ARRT Computed Tomography (CT) Certification Examination — Questions and Answers

Question 1: What is the minimum passing score typically required on the ARRT CT certification examination?

The ARRT uses a scaled score, not a percentage (Correct answer)
75
68
85

Correct answer: The ARRT uses a scaled score, not a percentage

ARRT reports exam results as a scaled score rather than a raw percentage, with 75 being the passing scaled score.

Question 2: Under ARRT's ethics requirements, a technologist who is convicted of a felony must do which of the following?

Request a voluntary suspension of registration
Immediately surrender their certificate
Self-report the conviction to ARRT (Correct answer)
Notify their state licensing board only

Correct answer: Self-report the conviction to ARRT

ARRT's Standards of Ethics require technologists to self-report criminal convictions, including felonies, to the ARRT within 30 days.

Question 3: What is the function of epithelial tissue?

To cover body surfaces, line cavities, and form glands (Correct answer)
To transmit electrical signals
To store fat
To contract and produce movement

Correct answer: To cover body surfaces, line cavities, and form glands

Epithelial tissue covers all body surfaces, lines body cavities and organs, and forms glands. It provides protection, absorption, secretion, and sensation.

Question 4: Which factor does NOT directly influence the CTDI_vol value displayed on the CT console?

Reconstruction kernel (filter) (Correct answer)
kVp
Pitch
Tube current (mAs)

Correct answer: Reconstruction kernel (filter)

Reconstruction kernel is a post-processing parameter applied after data acquisition and does not change the radiation output; CTDI_vol reflects acquisition parameters only.

Question 5: The annual occupational dose limit for the lens of the eye, as updated by NCRP Report No. 172, is:

20 mSv (Correct answer)
150 mSv
50 mSv
5 mSv

Correct answer: 20 mSv

NCRP Report No. 172 (2016) lowered the recommended annual occupational lens dose limit to 20 mSv/year averaged over 5 years, consistent with ICRP 103.

Question 6: Which entity must sponsor a continuing education activity for it to count toward ARRT CT recertification?

Any national radiology organization
The technologist's employing hospital
The American College of Radiology only
An ARRT-approved CE sponsor (Correct answer)

Correct answer: An ARRT-approved CE sponsor

ARRT only accepts Category A CE credits from activities provided by ARRT-approved sponsors, ensuring quality and relevance.

Question 7: Which CT post-processing technique displays only voxels above a selected threshold, making it useful for 3D visualization of bones and vascular structures?

Surface shaded display (SSD)
Volume rendering (VR)
Maximum intensity projection (MIP) (Correct answer)
Multiplanar reformation (MPR)

Correct answer: Maximum intensity projection (MIP)

Maximum intensity projection (MIP) selects and displays the highest attenuation voxel along each ray through the dataset, ideal for visualizing contrast-enhanced vessels or calcifications.

Question 8: Which CT quality control parameter is most directly affected by X-ray tube focal spot size?

Image noise
CT number uniformity
High-contrast spatial resolution (Correct answer)
Low-contrast detectability

Correct answer: High-contrast spatial resolution

A smaller focal spot produces sharper images with improved high-contrast spatial resolution because the geometric unsharpness is reduced.

Question 9: An applicant for ARRT CT certification discloses a prior misdemeanor conviction on their application. What happens next?

ARRT's Ethics Review Committee evaluates the disclosure on a case-by-case basis (Correct answer)
The application is automatically denied
The applicant must wait 10 years before reapplying
The conviction is ignored if more than 5 years old

Correct answer: ARRT's Ethics Review Committee evaluates the disclosure on a case-by-case basis

ARRT's Ethics Review Committee reviews all disclosed violations individually to determine eligibility.

Question 10: A candidate fails the ARRT CT examination. What is the minimum waiting period before their first retake?

6 months
3 months (Correct answer)
2 weeks
1 year

Correct answer: 3 months

ARRT requires a 3-month waiting period between examination attempts to allow candidates time for remediation.

Question 11: How many questions are typically included in the ARRT CT certification exam?

200
250
150 (Correct answer)
100

Correct answer: 150

The ARRT CT certification exam typically consists of 150 questions. This number includes both scored and unscored pilot questions, designed to comprehensively assess a candidate's knowledge across various domains of computed tomography. Candidates are given a specific time limit to complete all questions.

Question 12: A CT technologist is concerned about cumulative occupational dose. Which dosimeter provides the most accurate record of whole-body exposure?

Electronic personal dosimeter worn at waist
Finger ring TLD
Pocket ionization chamber
Optically stimulated luminescence (OSL) badge worn at collar level (Correct answer)

Correct answer: Optically stimulated luminescence (OSL) badge worn at collar level

An OSL badge worn at the collar (outside any lead apron) is the standard for whole-body occupational dose monitoring and provides accurate cumulative records.

Question 13: Partial volume averaging artifacts in CT are best reduced by which acquisition parameter adjustment?

Increasing kVp
Widening the display window
Increasing mAs
Using a thinner slice thickness (Correct answer)

Correct answer: Using a thinner slice thickness

Thinner slices reduce partial volume averaging by ensuring each voxel contains tissue from a smaller volume, improving accuracy of CT numbers.

Question 14: Which factor related to ARRT CT certification most directly contributes to long-term job security for a radiologic technologist?

ARRT monitors all employer actions against certified staff
Certification guarantees tenure after three years of employment
Employers cannot legally terminate certified employees
Certified technologists are more difficult to replace, increasing their value during staffing reductions (Correct answer)

Correct answer: Certified technologists are more difficult to replace, increasing their value during staffing reductions

Certified specialists are harder to replace than generalists, making them more valuable to departments and more likely to be retained during organizational changes.

Question 15: An applicant discloses a misdemeanor conviction on the ARRT ethics pre-application. What is the likely next step?

ARRT conducts an ethics review before granting or denying eligibility (Correct answer)
The misdemeanor is ignored if more than 5 years old
The applicant is approved with a probationary credential
The application is automatically denied

Correct answer: ARRT conducts an ethics review before granting or denying eligibility

Any disclosed violation triggers an ARRT ethics review, which evaluates the nature and context of the offense before deciding eligibility.

Question 16: The term 'NPO' means:

Non-painful observation
Nothing by mouth (Correct answer)
No prior operations
No pharmaceutical orders

Correct answer: Nothing by mouth

NPO is Latin for 'nil per os,' meaning nothing by mouth, and is used to restrict food and fluid intake before procedures or surgery.

Question 17: How does ARRT CT certification influence a technologist's ability to work at facilities affiliated with academic medical centers?

It only matters for technologists who also teach radiology students
Academic medical centers often require specialty certifications for positions involving advanced imaging modalities (Correct answer)
It is disqualifying because academic centers prefer non-certified staff
It is irrelevant because academic centers set their own competency standards independently of ARRT

Correct answer: Academic medical centers often require specialty certifications for positions involving advanced imaging modalities

Academic medical centers frequently list specialty ARRT certifications as required or preferred qualifications for CT positions due to their high-acuity patient populations.

Question 18: CT perfusion imaging requires specialized post-processing to generate which type of parametric maps?

Cerebral blood flow, cerebral blood volume, and mean transit time maps (Correct answer)
Standardized uptake value (SUV) maps
Hounsfield unit histograms
Bone mineral density scores

Correct answer: Cerebral blood flow, cerebral blood volume, and mean transit time maps

CT perfusion post-processing applies deconvolution or maximum slope models to time-attenuation curves to produce quantitative maps of CBF, CBV, and MTT.

Question 19: Under the ARRT ethics requirement, which of the following past offenses is MOST likely to result in denial of CT certification eligibility?

Unpaid parking tickets
A civil lawsuit unrelated to healthcare
Minor traffic violation
Felony conviction related to the practice of radiologic technology (Correct answer)

Correct answer: Felony conviction related to the practice of radiologic technology

Felony convictions, especially those related to healthcare practice, are subject to ARRT ethics review and can result in denial.

Question 20: A CT technologist who allows their ARRT registration to lapse must do which of the following to reinstate it?

Retake the primary certification exam
Complete a reinstatement application and pay the reinstatement fee (Correct answer)
Repeat clinical training
Apply through JRCERT for re-entry

Correct answer: Complete a reinstatement application and pay the reinstatement fee

Lapsed registrants must submit a reinstatement application with the appropriate fee and may need to fulfill CE requirements.

Question 21: On axial brain CT, the internal capsule is bounded medially by which structure?

Globus pallidus
Putamen
Thalamus
Caudate nucleus (Correct answer)

Correct answer: Caudate nucleus

The anterior limb of the internal capsule is bounded medially by the head of the caudate nucleus.

Question 22: CT of the knee shows a hyperdense line through the distal femoral epiphysis crossing the growth plate. This finding represents:

Osteochondral defect
Stress fracture
Salter-Harris type II fracture (Correct answer)
Physeal bar formation

Correct answer: Salter-Harris type II fracture

A Salter-Harris type II fracture extends through the physis and exits through the metaphysis, the most common physeal injury type.

Question 23: For a radiologic technologist considering subspecialty practice, which statement about ARRT CT certification scope is most accurate?

CT certification is equivalent to a fellowship in CT radiology
CT certification covers interventional radiology procedures as well
CT certification validates technical performance skills, not image interpretation or diagnosis (Correct answer)
CT certification qualifies technologists to independently interpret CT scans

Correct answer: CT certification validates technical performance skills, not image interpretation or diagnosis

ARRT CT certification validates technical performance and patient care competencies; image interpretation and diagnosis remain within the radiologist's scope.

Question 24: How is the ARRT Computed Tomography (CT) certification exam administered?

At a Pearson VUE testing center (Correct answer)
Through online remote proctoring
During an in-person workshop or seminar
In-person at a hospital or clinic

Correct answer: At a Pearson VUE testing center

The ARRT Computed Tomography (CT) certification exam is administered through a professional testing service. Candidates are required to schedule and take their exam at an authorized Pearson VUE testing center. These centers provide a standardized, secure, and proctored environment for examinations.

Question 25: Which of the following is a valid reason ARRT may revoke or suspend a technologist's CT certification?

Transferring employment to a different imaging facility
Failure to update a home address in the ARRT database
Violation of the ARRT Standards of Ethics (Correct answer)
Completing CE credits after the renewal deadline

Correct answer: Violation of the ARRT Standards of Ethics

ARRT can revoke or suspend certification for violations of its Standards of Ethics, which govern professional and personal conduct.

Question 26: Which CT feature of a pulmonary nodule is most associated with malignancy?

Laminated calcification pattern
Spiculated margins with pleural tethering (Correct answer)
Stippled central calcification
Smooth well-defined margins

Correct answer: Spiculated margins with pleural tethering

Spiculated margins with pleural tethering are high-risk features indicating likely malignant invasion of adjacent lung parenchyma.

Question 27: On a CT image at the level of C6, which structure occupies the anterior midline of the neck?

Common carotid artery
Trachea
Esophagus
Thyroid gland (Correct answer)

Correct answer: Thyroid gland

The thyroid gland wraps anteriorly around the trachea at the C5-C6 level, occupying the anterior midline.

Question 28: The ARRT CT post-primary examination is a computer-based test (CBT). Approximately how many scored questions does it contain?

165 questions (Correct answer)
75 questions
100 questions
200 questions

Correct answer: 165 questions

The ARRT CT examination consists of approximately 165 scored questions plus a small number of unscored pilot questions.

Question 29: ARRT certification in CT is best described as which type of credential?

Entry-level primary certification
Academic degree credential
Post-primary specialty certification (Correct answer)
State-issued license

Correct answer: Post-primary specialty certification

CT certification is a post-primary specialty credential, meaning it is layered on top of a primary ARRT certification in a related discipline.

Question 30: What is the role of the ARRT Board of Trustees in the accreditation and credentialing process?

They perform on-site inspections of clinical training sites
They issue state radiologic technology licenses
They directly score individual certification examinations
They govern ARRT policy, including eligibility requirements and ethical standards (Correct answer)

Correct answer: They govern ARRT policy, including eligibility requirements and ethical standards

The ARRT Board of Trustees is the governing body responsible for setting policy, eligibility criteria, and ethical standards for the organization.

Question 31: Which reconstruction kernel (filter) should be chosen to minimize noise when imaging soft tissue structures in the abdomen?

Smooth or standard soft tissue kernel (Correct answer)
Lung kernel
Ultra-high resolution kernel
Bone or edge-enhancing kernel

Correct answer: Smooth or standard soft tissue kernel

Soft tissue kernels apply low-pass filtering that smooths the image and reduces noise, which is appropriate for abdominal soft tissue evaluation.

Question 32: Which of the following would trigger an automatic review by the ARRT Ethics Review Committee?

A program director retiring
A technologist failing to submit CE on time
A technologist changing their employer
A credential holder being convicted of a felony (Correct answer)

Correct answer: A credential holder being convicted of a felony

A felony conviction is a serious ethics matter that ARRT's Ethics Review Committee must evaluate to determine whether the credential can be maintained.

Question 33: Which ACR-recommended CT quality control test should be performed if visual image artifacts are noted during clinical scanning?

Switch to a different reconstruction kernel and continue scanning
Perform artifact analysis using an appropriate phantom and document findings before continuing clinical use (Correct answer)
Immediately repeat the patient scan at higher mAs
Reduce the scan FOV and repeat without QC evaluation

Correct answer: Perform artifact analysis using an appropriate phantom and document findings before continuing clinical use

When clinical artifacts are observed, ACR guidelines require phantom-based artifact analysis and documentation before continuing patient scanning to ensure diagnostic image quality.

Question 34: Increasing the reconstruction field of view (FOV) while keeping matrix size constant will:

Decrease pixel size and increase spatial resolution
Increase pixel size and decrease spatial resolution (Correct answer)
Have no effect on spatial resolution
Increase noise while improving contrast

Correct answer: Increase pixel size and decrease spatial resolution

Larger FOV with the same matrix means each pixel covers more area, increasing pixel size and reducing spatial resolution.

Question 35: Which generator component is responsible for converting AC power to the high-voltage DC supply required by the X-ray tube in modern CT systems?

Autotransformer
High-frequency inverter generator (Correct answer)
Rectifier diode bridge
Filament transformer

Correct answer: High-frequency inverter generator

Modern CT systems use high-frequency inverter generators that convert line AC to high-frequency AC, then rectify it to produce a near-constant high-voltage DC supply for the tube.

Question 36: How many continuing education credits must ARRT-registered CT technologists earn during each 2-year renewal cycle?

12 credits
24 credits (Correct answer)
36 credits
48 credits

Correct answer: 24 credits

ARRT requires 24 Category A continuing education credits per 2-year renewal cycle for registered technologists.

Question 37: Curved planar reformation (CPR) in CT is most useful for:

Generating endoscopic views of hollow organs
Subtracting bone from CT angiography images
Straightening and displaying tortuous structures such as vessels or the spine along their entire length (Correct answer)
Creating color-coded perfusion maps

Correct answer: Straightening and displaying tortuous structures such as vessels or the spine along their entire length

CPR follows a user-defined curved path through the volume dataset to display a tortuous structure in a single unfolded plane, useful for coronary arteries or the aorta.

Question 38: A patient receiving IV contrast media suddenly develops stridor and facial edema 5 minutes after injection. These findings are most consistent with:

Contrast nephropathy
Vasovagal reaction
Phlebitis at the injection site
Anaphylactoid reaction (Correct answer)

Correct answer: Anaphylactoid reaction

Stridor (upper airway obstruction) and facial edema are hallmark signs of anaphylactoid reaction, requiring immediate epinephrine and airway management.

Question 39: The inverse square law states that radiation intensity is related to distance by which relationship?

Intensity decreases linearly with distance
Intensity is directly proportional to distance
Intensity is inversely proportional to the cube of the distance
Intensity is inversely proportional to the square of the distance (Correct answer)

Correct answer: Intensity is inversely proportional to the square of the distance

The inverse square law: I ∝ 1/d², meaning doubling the distance from the source reduces intensity to one-quarter of its original value.

Question 40: 3D volume rendering of CT data allows the display of internal structures through which technique?

Subtracting bone from the dataset
Selecting only the highest attenuation voxel per projection ray
Applying a smooth kernel to the raw data
Assigning opacity values to voxels based on their Hounsfield units (Correct answer)

Correct answer: Assigning opacity values to voxels based on their Hounsfield units

Volume rendering assigns transfer functions that map each HU value to a color and opacity, allowing semi-transparent visualization of multiple tissue types simultaneously.

Question 41: For a pediatric CT head scan, compared to an adult protocol, the technologist should generally:

Increase kVp to 140 kV to penetrate the skull
Reduce mAs significantly because children are more radiosensitive and smaller (Correct answer)
Extend scan length to cover the entire neuraxis
Use the same mAs to ensure adequate image quality

Correct answer: Reduce mAs significantly because children are more radiosensitive and smaller

Children have greater radiosensitivity and smaller body dimensions, so pediatric CT protocols use substantially lower mAs than adult protocols.

Question 42: What is the purpose of contrast media in CT scans?

To make the patient comfortable
To enhance the visibility of specific structures and pathology (Correct answer)
To reduce radiation dose
To speed up the scan

Correct answer: To enhance the visibility of specific structures and pathology

Contrast media (dye) enhances the visibility of blood vessels, organs, and abnormalities by changing how X-rays interact with specific tissues.

Question 43: Which structure forms the posterior boundary of the adrenal glands on axial CT images?

Quadratus lumborum muscle
Psoas major muscle
Diaphragmatic crura (Correct answer)
Perirenal fat

Correct answer: Diaphragmatic crura

The diaphragmatic crura form the posterior border of the adrenal glands, which lie in the perirenal space.

Question 44: Under the ARRT primary pathway, how must a Nuclear Medicine Technology (N) credential holder demonstrate CT clinical competency?

By substituting nuclear medicine competencies for CT competencies
By completing an online simulation module
By passing only the written CT exam without clinical requirements
By completing CT-specific competency tasks under the supervision of a qualified supervisor (Correct answer)

Correct answer: By completing CT-specific competency tasks under the supervision of a qualified supervisor

Regardless of primary credential, all CT candidates must complete designated CT clinical competencies under appropriate supervision.

Question 45: What happens to a technologist's post-primary CT certification if their primary ARRT registration lapses?

Only the primary registration lapses; post-primary certifications are unaffected
The CT certification converts to an inactive status automatically
The CT certification also lapses because it depends on primary registration status (Correct answer)
The CT certification remains active independently

Correct answer: The CT certification also lapses because it depends on primary registration status

Post-primary certifications such as CT are dependent on an active primary ARRT registration; if the primary lapses, so does the post-primary certification.

Question 46: What is the window level and window width on CT images?

Scan speed controls
Settings that control the brightness and contrast of displayed images (Correct answer)
Physical measurements of the CT scanner
Patient positioning parameters

Correct answer: Settings that control the brightness and contrast of displayed images

Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).

Question 47: Which artifact appears as bright or dark bands radiating from high-density structures like metal implants?

Beam hardening artifact
Ring artifact
Streak artifact (Correct answer)
Partial volume artifact

Correct answer: Streak artifact

Streak artifacts arise from highly attenuating objects (metal, dense bone) causing inconsistent projections that reconstruct as linear streaks.

Question 48: The spatial frequency at which the MTF falls to 10% is commonly used to define:

The limiting spatial resolution of the CT system (Correct answer)
The optimal reconstruction FOV
The detective quantum efficiency (DQE)
The noise power spectrum peak

Correct answer: The limiting spatial resolution of the CT system

MTF10% represents the highest spatial frequency the system can transfer with 10% modulation, effectively defining the limiting resolution.

Question 49: What is the chain of command?

A type of equipment
A combat formation
The hierarchical structure of authority in a military organization (Correct answer)
A supply system

Correct answer: The hierarchical structure of authority in a military organization

The chain of command is the line of authority along which orders pass from the highest rank to the lowest.

Question 50: Under NRC regulations, which of the following events involving a CT scanner MUST be reported as a medical event?

Using a slightly higher mAs than the standard protocol
Scanning without verbal confirmation of the patient's name
Delivery of a dose differing from the prescribed dose by more than 50 mSv effective dose or 500 mSv to an organ when not due to patient condition (Correct answer)
A scan performed 2 cm longer than prescribed due to patient movement

Correct answer: Delivery of a dose differing from the prescribed dose by more than 50 mSv effective dose or 500 mSv to an organ when not due to patient condition

A medical event under 10 CFR 35.3045 requires reporting when the wrong patient receives a dose, or dose differs from the prescribed dose by >50 mSv effective dose or >500 mSv to any organ.

Question 51: A ring or band artifact centered on the image is most likely caused by a malfunction of which CT component?

A single detector element (Correct answer)
Gantry motor
X-ray tube
Collimator

Correct answer: A single detector element

Ring artifacts result from a miscalibrated or malfunctioning detector element producing a circular artifact at a fixed radius from the isocenter.

Question 52: What is the primary purpose of selecting a small reconstruction FOV (field of view) during CT image reconstruction?

To reduce patient dose
To improve spatial resolution by sampling more detail per pixel (Correct answer)
To decrease image noise
To increase the pixel size for better soft tissue contrast

Correct answer: To improve spatial resolution by sampling more detail per pixel

A smaller reconstruction FOV divides the imaged area into the same matrix of pixels, resulting in smaller pixel size and therefore higher spatial resolution of the region of interest.

Question 53: What type of artifact appears as bright or dark streaks radiating from high-density objects like metal implants in CT images?

Ring artifact
Beam hardening artifact (Correct answer)
Motion artifact
Partial volume artifact

Correct answer: Beam hardening artifact

Beam hardening artifacts appear as streaks or dark bands radiating from dense metallic objects because lower-energy photons are preferentially absorbed.

Question 54: A CT myelography protocol requires which patient preparation step unique to this exam?

Intrathecal injection of iodinated contrast (Correct answer)
IV injection of gadolinium contrast
Fasting for 6 hours prior
Oral bowel prep the night before

Correct answer: Intrathecal injection of iodinated contrast

CT myelography requires intrathecal (subarachnoid) injection of water-soluble iodinated contrast to opacify the spinal canal.

Question 55: On axial brain CT, the sylvian fissure (lateral sulcus) separates which lobes?

Frontal lobe from the parietal lobe only
Frontal lobe from occipital lobe
Parietal lobe from occipital lobe
Frontal and parietal lobes from the temporal lobe (Correct answer)

Correct answer: Frontal and parietal lobes from the temporal lobe

The sylvian (lateral) fissure separates the frontal and parietal lobes superiorly from the temporal lobe inferiorly.

Question 56: Which daily CT quality control test verifies that CT numbers (Hounsfield Units) remain accurate and consistent?

High-contrast spatial resolution test
CT number accuracy/linearity test (Correct answer)
Noise index measurement
Slice thickness verification

Correct answer: CT number accuracy/linearity test

The CT number accuracy/linearity test confirms that scanned materials produce the expected HU values, ensuring diagnostic consistency.

Question 57: Which scenario best illustrates the career portability benefit of ARRT CT certification?

A technologist is locked into their current employer for 5 years after certification
The credential expires immediately upon leaving an employer
A certified CT tech is recognized by employers nationwide without needing to retake facility-specific competency exams (Correct answer)
Certification is only valid in the state where the exam was taken

Correct answer: A certified CT tech is recognized by employers nationwide without needing to retake facility-specific competency exams

Because ARRT is a national credential, certified technologists can demonstrate competency to employers anywhere in the US, facilitating geographic and career mobility.

Question 58: Which educational qualification is acceptable for ARRT CT certification?

A certification in sonography
Completion of an accredited educational program in computed tomography (Correct answer)
A diploma from a CT-specific online program
Any degree in health sciences

Correct answer: Completion of an accredited educational program in computed tomography

For ARRT CT certification, candidates must demonstrate a specific educational background directly relevant to CT imaging. This typically involves completing an accredited educational program that focuses on computed tomography. Such programs ensure candidates acquire the specialized knowledge and skills necessary for safe and effective CT practice.

Question 59: A horizontal band of decreased attenuation passing through the posterior fossa on a head CT is a classic example of which artifact?

Motion artifact from cardiac pulsation
Beam hardening between the petrous bones (Correct answer)
Ring artifact
Partial volume artifact

Correct answer: Beam hardening between the petrous bones

The dense petrous temporal bones cause preferential absorption of lower-energy photons, producing a dark band across the posterior fossa known as a beam hardening artifact.

Question 60: A delayed adverse reaction to iodinated contrast media most commonly occurs within what timeframe after injection?

Within 1 minute
1–60 minutes
1 hour to 1 week (Correct answer)
More than 2 weeks

Correct answer: 1 hour to 1 week

Delayed adverse reactions, often skin reactions such as rash or urticaria, typically occur between 1 hour and 1 week after contrast administration.

Question 61: A starburst pattern of streaks emanating from the edge of the patient's shoulders during a neck CT is most likely caused by:

Detector malfunction
Gantry tilt error
Beam hardening from bone and soft tissue interfaces (Correct answer)
Incorrect windowing

Correct answer: Beam hardening from bone and soft tissue interfaces

Dense cortical bone at the shoulder causes beam hardening, producing characteristic streak artifacts that radiate into adjacent soft tissues.

Question 62: What is the ALARA principle in radiation safety?

All Labs And Rooms Assessed
Automated Limiting Adjustment for Radiation Applications
As Low As Reasonably Achievable — minimize radiation exposure (Correct answer)
Always Lock And Restrict Access

Correct answer: As Low As Reasonably Achievable — minimize radiation exposure

ALARA means keeping radiation doses as low as reasonably achievable while still obtaining diagnostic-quality images, balancing benefit against risk.

Question 63: In CT, 'effective mAs' (mAs/pitch) is important because:

It determines the field of view
It controls the display window
It sets the rotation time only
It remains constant regardless of pitch, maintaining image noise consistency (Correct answer)

Correct answer: It remains constant regardless of pitch, maintaining image noise consistency

Effective mAs = mAs ÷ pitch; keeping this constant as pitch changes maintains consistent image noise regardless of table speed.

Question 64: Which of the following best describes a 'dual-phase' liver CT protocol?

Non-contrast and delayed phases only
Portal venous and delayed phases only
Non-contrast and arterial phases only
Arterial and portal venous phases (Correct answer)

Correct answer: Arterial and portal venous phases

A dual-phase liver protocol acquires images in both the hepatic arterial phase and the portal venous phase to characterize liver lesions.

Question 65: A technologist holds both ARRT Radiography (R) and MRI (MR) credentials. To add CT certification, which credential serves as the qualifying primary pathway?

Both credentials must be listed; neither alone qualifies
Only MRI (MR) qualifies
Only Radiography (R) qualifies
Either R or MR can serve as the qualifying primary credential (Correct answer)

Correct answer: Either R or MR can serve as the qualifying primary credential

ARRT allows multiple qualifying primary pathways for CT, so either an active R or MR credential can serve as the qualifying base.

Question 66: In CT dose reporting, CTDI_vol represents:

Dose at a single point in the patient
Total energy deposited in the room
Dose only at the center of the phantom
Volume-averaged radiation dose within the scan volume (Correct answer)

Correct answer: Volume-averaged radiation dose within the scan volume

CTDI_vol is the volume CT dose index, representing average dose within the irradiated volume; it accounts for pitch in helical scanning.

Question 67: How long is the ARRT CT post-primary certification credential valid before renewal is required?

2 years (biennium) (Correct answer)
Lifetime with no renewal
1 year
5 years

Correct answer: 2 years (biennium)

Like all ARRT credentials, CT post-primary certification must be renewed every two years through the biennial renewal process.

Question 68: How does ARRT CT certification support a technologist's participation in quality improvement initiatives within their department?

It only applies to patient scheduling improvements
It provides the advanced protocol and dose optimization knowledge needed to contribute meaningfully to QI projects (Correct answer)
It transfers QI responsibilities entirely to the radiologist
It disqualifies technologists from serving on quality committees

Correct answer: It provides the advanced protocol and dose optimization knowledge needed to contribute meaningfully to QI projects

The depth of CT knowledge required for ARRT certification equips technologists to identify protocol inefficiencies, dose issues, and image quality problems in QI settings.

Question 69: What is the primary purpose of ARRT's structured competency-based renewal requirements for CT certification?

To align with Medicare billing requirements
To increase revenue for the ARRT organization
To ensure technologists maintain current knowledge and skills (Correct answer)
To limit the number of active CT technologists

Correct answer: To ensure technologists maintain current knowledge and skills

ARRT's renewal structure is designed to ensure that certified professionals stay current with evolving technology, safety standards, and clinical practice.

Question 70: What is the primary advantage of CT over conventional X-ray?

CT provides cross-sectional images with superior soft tissue contrast (Correct answer)
CT takes less time
CT uses no radiation
CT is cheaper

Correct answer: CT provides cross-sectional images with superior soft tissue contrast

CT provides detailed cross-sectional images with much better soft tissue contrast resolution than conventional X-rays, allowing visualization of subtle differences between tissues.

Question 71: When performing a CT colonography, the technologist selects a 0.625 mm detector row width versus 5 mm. This change PRIMARILY improves:

Temporal resolution for cardiac gating
Contrast resolution for soft tissue differentiation
Patient dose efficiency
Longitudinal (z-axis) spatial resolution enabling multiplanar reformats (Correct answer)

Correct answer: Longitudinal (z-axis) spatial resolution enabling multiplanar reformats

Thinner detector rows provide finer z-axis sampling, enabling isotropic voxels and high-quality multiplanar reformats for polyp detection.

Question 72: Which of the following is the correct documentation entry after administering IV contrast?

Contrast given per radiologist order
Type of contrast, lot number, dose, route, rate, patient response, and technologist's signature (Correct answer)
Patient tolerated procedure well
Contrast given — no issues noted

Correct answer: Type of contrast, lot number, dose, route, rate, patient response, and technologist's signature

Complete contrast documentation must include the agent name, lot number, dose, route, rate of administration, patient response, and the administering technologist's identification.

Question 73: When transferring a patient from a wheelchair to the radiographic table, the wheelchair should be positioned at what angle relative to the table?

90 degrees
45 degrees (Correct answer)
Parallel and touching the table
180 degrees

Correct answer: 45 degrees

Positioning the wheelchair at approximately 45 degrees to the table allows the shortest, most controlled pivot transfer for the patient.

Question 74: What is the significance of ARRT accreditation reciprocity with respect to international technologists seeking U.S. credentials?

ARRT has formal reciprocity agreements with all countries
Foreign technologists are exempt from the ethics review
ARRT does not grant reciprocity; international candidates must meet all ARRT eligibility requirements independently (Correct answer)
Foreign credentials are automatically accepted as equivalent to ARRT certification

Correct answer: ARRT does not grant reciprocity; international candidates must meet all ARRT eligibility requirements independently

ARRT does not have reciprocity agreements with foreign credentialing bodies; all candidates must independently meet ARRT's eligibility and examination requirements.

Question 75: Which scan parameter adjustment would best reduce streak artifact from dental fillings on a head/neck CT?

Decrease tube voltage
Increase tube current (mA)
Decrease rotation time
Use gantry tilt to avoid the plane of the fillings (Correct answer)

Correct answer: Use gantry tilt to avoid the plane of the fillings

Tilting the gantry angles the scan plane away from dense dental hardware, reducing the metal streak artifact through structures of interest.

Question 76: In CT, the term 'isotropic voxel' means:

The voxel's HU value is calibrated to water
The voxel represents a single tissue type
The voxel dimensions are equal in all three axes (x, y, z) (Correct answer)
The voxel has no noise contribution

Correct answer: The voxel dimensions are equal in all three axes (x, y, z)

An isotropic voxel has equal dimensions in x, y, and z directions, enabling multiplanar reformats of equal quality in any plane.

Question 77: In CT, the filtered back projection (FBP) reconstruction algorithm applies a mathematical filter primarily to:

Remove quantum noise before reconstruction
Align misregistered projection data
Correct for star artifacts inherent in simple back projection (Correct answer)
Segment soft tissue from bone

Correct answer: Correct for star artifacts inherent in simple back projection

FBP applies a ramp or other convolution filter to projection data before back-projecting to eliminate the blurring ('star artifact') produced by simple back projection.

Question 78: What does the term 'half-scan reconstruction' refer to in CT?

Reconstructing only half the detector channels
Using 180° + fan angle of data instead of a full 360° to reduce motion artifact (Correct answer)
Acquiring data with only half normal mAs
Reducing matrix size by half to speed processing

Correct answer: Using 180° + fan angle of data instead of a full 360° to reduce motion artifact

Half-scan reconstruction uses approximately 180° + fan beam angle of data, which can reduce cardiac or other motion artifacts by shortening effective scan time.

Question 79: The Hounsfield unit (HU) value of pure water is:

+100
0 (Correct answer)
-1000
+1000

Correct answer: 0

By definition, pure water is assigned an HU value of 0 on the Hounsfield scale used in CT imaging.

Question 80: What is the fire triangle?

Three fire departments
Three fire escape routes
Three types of fire extinguishers
Heat, fuel, and oxygen — the three elements needed for fire (Correct answer)

Correct answer: Heat, fuel, and oxygen — the three elements needed for fire

The fire triangle illustrates the three elements required for combustion: heat (ignition source), fuel (combustible material), and oxygen. Removing any one element extinguishes the fire.

Question 81: When comparing filtered back projection (FBP) to model-based iterative reconstruction (MBIR) at matched noise levels, MBIR typically demonstrates:

Lower spatial resolution but equivalent noise
Equivalent resolution but increased beam hardening artifacts
Longer reconstruction times with no image quality advantage
Higher spatial resolution with fewer artifacts at lower dose (Correct answer)

Correct answer: Higher spatial resolution with fewer artifacts at lower dose

MBIR models the entire imaging chain including optics and statistics, achieving better resolution and artifact suppression at lower dose than FBP.

Question 82: Which reconstruction kernel (filter) choice produces the HIGHEST spatial resolution but MOST noise in CT?

Sharp/edge-enhancing kernel (Correct answer)
Lung kernel
Soft/smooth kernel
Standard kernel

Correct answer: Sharp/edge-enhancing kernel

Sharp or bone kernels enhance high-frequency data to improve edge detail but amplify noise, making them high-resolution but noisy.

Question 83: For a CT coronary angiography (CCTA) protocol, which heart rate range is generally ideal to minimize motion artifact?

<65 bpm (Correct answer)
>100 bpm
65–80 bpm
80–100 bpm

Correct answer: <65 bpm

Heart rates below 65 bpm allow longer diastolic rest periods, reducing cardiac motion artifact during CCTA acquisition.

Question 84: A technologist discovers an error in their ARRT certification record. What is the appropriate first step?

Contact ARRT directly to request a correction through official channels (Correct answer)
File a complaint with the state radiology board
Notify JRCERT of the discrepancy
Retake the examination to establish a new record

Correct answer: Contact ARRT directly to request a correction through official channels

ARRT manages its own credential records, so technologists should contact ARRT directly to resolve record discrepancies.

Question 85: Which statement best describes the principle of informed consent?

Consent is implied once the patient enters the radiology department
Consent may be obtained by any staff member regardless of their role
The patient must be given a full explanation of the procedure, risks, benefits, and alternatives before voluntarily agreeing (Correct answer)
The patient signs a form without needing a full explanation of the procedure

Correct answer: The patient must be given a full explanation of the procedure, risks, benefits, and alternatives before voluntarily agreeing

Informed consent requires full disclosure of the procedure, risks, benefits, and alternatives so the patient can make a voluntary, knowledgeable decision.

Question 86: Aliasing artifacts in CT most commonly occur due to:

Insufficient angular sampling of projection data (undersampling) (Correct answer)
High patient body mass index
Calibration errors in the slip ring
Overuse of iterative reconstruction

Correct answer: Insufficient angular sampling of projection data (undersampling)

Aliasing arises when the sampling rate of projection views is too low to accurately represent fine detail, producing Moiré-like or streak patterns.

Question 87: On axial CT of the knee, the iliotibial band is best identified at which location?

Anteromedial compartment between the patellar tendon and medial collateral ligament
Lateral aspect of the knee, inserting on Gerdy's tubercle of the tibia (Correct answer)
Posterolateral aspect of the knee, inserting on the femoral condyle
Posterior to the lateral collateral ligament at the fibular head

Correct answer: Lateral aspect of the knee, inserting on Gerdy's tubercle of the tibia

The iliotibial band runs along the lateral thigh and inserts on Gerdy's tubercle on the anterolateral tibia.

Question 88: A CT technologist retires and allows their ARRT registration to expire for 8 years, then wishes to return to practice. What is required?

A letter of recommendation from a radiologist
Submission of a reinstatement fee only
Completion of 24 CE credits and a reinstatement fee
Retaking the ARRT CT certification examination (Correct answer)

Correct answer: Retaking the ARRT CT certification examination

After an extended lapse beyond ARRT's reinstatement window, technologists are typically required to retake the certification examination to demonstrate current competency.

Question 89: CT window width (WW) setting controls which aspect of image display?

The center Hounsfield unit of the gray scale
The spatial resolution of the image
The overall brightness of the image
The range of Hounsfield units displayed as the full gray scale from black to white (Correct answer)

Correct answer: The range of Hounsfield units displayed as the full gray scale from black to white

Window width determines the range of CT numbers (HU) mapped to the grayscale; a narrow window increases contrast but limits the HU range displayed.

Question 90: When evaluating a CT image for streak artifacts emanating from a hip prosthesis, the BEST corrective technique is:

Decreasing the mAs by 50%
Metal artifact reduction (MAR) reconstruction algorithm (Correct answer)
Increasing the kVp to 140
Widening the reconstruction FOV

Correct answer: Metal artifact reduction (MAR) reconstruction algorithm

Metal artifact reduction algorithms use iterative or sinogram-based techniques to model and subtract metal-induced streaks from the image.

Question 91: The windmill artifact seen in helical CT is most commonly associated with which acquisition parameter?

High pitch values (Correct answer)
Low kVp
Large detector collimation
Small reconstruction FOV

Correct answer: High pitch values

Windmill artifacts appear as alternating dark and bright streaks rotating around structures and are caused by the under-sampling that occurs at high pitch values.

Question 92: Which statement BEST describes the relationship between CT noise and mAs?

Noise is inversely proportional to mAs
Noise is proportional to 1/√mAs (Correct answer)
Noise is directly proportional to mAs
Noise is unaffected by mAs changes

Correct answer: Noise is proportional to 1/√mAs

CT noise follows Poisson statistics; doubling mAs quadruples photons but only reduces noise by a factor of √2, making noise proportional to 1/√mAs.

Question 93: On a CT scanner, what does image uniformity testing evaluate?

The linearity of dose output versus mAs
The consistency of CT numbers across the field of view in a homogeneous phantom (Correct answer)
The accuracy of the patient table indexing
The ability to visualize small high-contrast structures

Correct answer: The consistency of CT numbers across the field of view in a homogeneous phantom

Image uniformity testing measures whether a homogeneous phantom (e.g., water) produces consistent HU values across the entire reconstructed image.

Question 94: Which of the following best describes the continuing education requirement to maintain ARRT CT certification?

10 credits per year with no renewal cycle
No continuing education is required once certified
50 continuing education credits every 5 years
24 continuing education credits every 2 years (Correct answer)

Correct answer: 24 continuing education credits every 2 years

ARRT requires 24 continuing education credits biennially to maintain all post-primary certifications including CT.

Question 95: When noise in a CT image is described as 'quantum mottle,' it most directly reflects:

Electronic noise in the detector
Software processing errors
Statistical variation in the number of photons detected (Correct answer)
Mechanical vibration of the gantry

Correct answer: Statistical variation in the number of photons detected

Quantum mottle (quantum noise) results from statistical variations in photon fluence reaching the detector, following Poisson statistics.

Question 96: What should a candidate do immediately after passing the ARRT CT certification exam?

Submit documentation of continuing education hours
Wait for the official certification certificate to be mailed (Correct answer)
Apply for state licensure in radiology
Begin their recertification process

Correct answer: Wait for the official certification certificate to be mailed

After successfully passing the ARRT CT certification exam, the immediate next step for a candidate is to await the official documentation. The ARRT will process the results and mail the certification certificate to the newly certified technologist. This certificate serves as formal proof of their credential.

Question 97: Which reconstruction field of view (FOV) is most appropriate when performing targeted high-resolution CT of the temporal bone?

50 cm (full body FOV)
10–15 cm (small targeted FOV) (Correct answer)
25 cm (medium FOV)
40 cm (large FOV)

Correct answer: 10–15 cm (small targeted FOV)

A 10–15 cm reconstruction FOV over the temporal bone maximizes pixel density within the small region of interest, yielding the highest possible spatial resolution.

Question 98: What is the function of red blood cells?

To fight infection
To produce hormones
To transport oxygen from lungs to tissues and CO2 back (Correct answer)
To clot blood

Correct answer: To transport oxygen from lungs to tissues and CO2 back

Red blood cells (erythrocytes) contain hemoglobin that binds oxygen in the lungs and delivers it to tissues, then carries carbon dioxide back for exhalation.

Question 99: An imaging manager reviewing candidates for a CT position ranks an ARRT(CT)-certified applicant higher than an uncertified one. Which professional benefit does this reflect?

Lower salary demands from certified candidates
Guaranteed productivity metrics from certified staff
Competitive advantage in the job market due to validated specialty competency (Correct answer)
Reduced need for the certified technologist to attend department meetings

Correct answer: Competitive advantage in the job market due to validated specialty competency

ARRT CT certification provides a competitive edge during hiring by assuring employers of validated, standardized CT competency without requiring internal testing.

Question 100: Which scan phase best demonstrates hepatic metastases that are hypervascular?

Portal venous phase
Delayed phase
Non-contrast phase
Hepatic arterial phase (Correct answer)

Correct answer: Hepatic arterial phase

Hypervascular metastases enhance avidly during the hepatic arterial phase when liver parenchyma enhancement is low, maximizing lesion-to-liver contrast.

Question 101: A newly certified CT technologist wants to transition from a general hospital to an outpatient imaging center. How does ARRT CT certification help?

It automatically transfers the technologist's state license to the new facility
It demonstrates specialized competency that outpatient centers increasingly require for hiring (Correct answer)
It eliminates the need for any additional facility orientation
It restricts employment to inpatient facilities only

Correct answer: It demonstrates specialized competency that outpatient centers increasingly require for hiring

Outpatient imaging centers often prefer or require ARRT CT certification as proof of specialized competency, making job transitions easier.

Question 102: A CT abdomen reveals a liver lesion that is hypodense on non-contrast, enhances intensely on arterial phase, and becomes isodense to liver on portal venous phase. This pattern is most consistent with:

Cholangiocarcinoma
Hepatocellular carcinoma (Correct answer)
Hepatic hemangioma
Focal nodular hyperplasia

Correct answer: Hepatocellular carcinoma

Arterial hyperenhancement with washout on portal venous phase is the classic CT hallmark of hepatocellular carcinoma.

Question 103: Which of these statements is true about eligibility for ARRT CT certification?

Applicants must hold an existing ARRT certification in an eligible primary pathway discipline. (Correct answer)
Clinical competencies must be completed after passing the CT exam.
Holding a state radiography license is enough to apply for certification.
Only professionals with a master's degree can apply for CT certification.

Correct answer: Applicants must hold an existing ARRT certification in an eligible primary pathway discipline.

ARRT CT certification is considered a post-primary certification, meaning it builds upon a foundational credential. Therefore, a prerequisite for applying is holding an active ARRT certification in a primary pathway discipline such as radiography, nuclear medicine technology, or radiation therapy. This ensures applicants have a core understanding of medical imaging principles.

Question 104: On axial CT of the chest, the right and left main bronchi are best distinguished because:

The right main bronchus is shorter and more vertical, making aspiration more likely (Correct answer)
The left main bronchus is shorter and more vertical than the right
The right main bronchus is longer and more horizontal than the left
The left main bronchus has a larger caliber than the right

Correct answer: The right main bronchus is shorter and more vertical, making aspiration more likely

The right main bronchus is shorter, wider, and more vertical, which is why aspirated foreign bodies most commonly lodge on the right side.

Question 105: Which of the following best describes an out-of-field artifact in CT?

Noise from low mAs
Streaking caused by anatomy extending beyond the scan FOV (Correct answer)
Ring caused by detector failure
Blurring from respiratory motion

Correct answer: Streaking caused by anatomy extending beyond the scan FOV

Out-of-field artifacts occur when part of the patient's anatomy lies outside the calibrated scan FOV, causing truncation of projection data and bright peripheral streaks.

Question 106: Which measurement best quantifies the amount of iodine delivered to a patient per unit time during a CT angiography injection?

Iodine concentration in mg/mL alone
Total contrast volume in mL
Injection pressure in PSI
Iodine delivery rate (IDR) expressed as grams of iodine per second (Correct answer)

Correct answer: Iodine delivery rate (IDR) expressed as grams of iodine per second

Iodine delivery rate (IDR = concentration [mgI/mL] × flow rate [mL/s]) determines the rate of iodine reaching the vascular system and predicts enhancement quality better than volume alone.

Question 107: In multi-detector CT (MDCT), increasing the number of detector rows primarily allows:

Elimination of pitch requirements
Higher kVp settings
Simultaneous acquisition of more slices per rotation, improving z-axis coverage speed (Correct answer)
Reduced x-ray tube heat loading per scan

Correct answer: Simultaneous acquisition of more slices per rotation, improving z-axis coverage speed

More detector rows mean more slice data acquired per rotation, covering a larger anatomical volume per gantry revolution and reducing scan time.

Question 108: Stochastic effects of radiation are characterized by which of the following?

Occurring only in radiosensitive tissues such as bone marrow
A threshold dose below which the effect cannot occur
Severity increasing proportionally with dose above the threshold
No dose threshold; probability of occurrence increases with dose (Correct answer)

Correct answer: No dose threshold; probability of occurrence increases with dose

Stochastic effects (e.g., radiation-induced cancer) are assumed to have no threshold; their probability, not severity, increases with dose.

Question 109: A CT technologist with ARRT CT certification wants to teach at a community college radiologic technology program. How does the certification help?

It demonstrates content expertise that many programs require or prefer for adjunct CT instructors (Correct answer)
It only qualifies the technologist to teach radiography, not CT specifically
It automatically grants a teaching license in all states
It is a disqualifying credential for educational roles

Correct answer: It demonstrates content expertise that many programs require or prefer for adjunct CT instructors

Community college and vocational radiologic technology programs often require or prefer instructors to hold advanced ARRT credentials in the specialty they are teaching.

Question 110: What is the purpose of a risk assessment?

To identify potential hazards and determine mitigation measures (Correct answer)
To track inventory levels
To calculate financial budgets
To assign work shifts

Correct answer: To identify potential hazards and determine mitigation measures

Risk assessments identify potential hazards, evaluate the likelihood and severity of harm, and determine appropriate controls to minimize risk.

Question 111: Which category of ARRT continuing education credit requires direct patient care activities or case-based learning?

Category B
Category A (Correct answer)
Category D
Category C

Correct answer: Category A

ARRT Category A credits are structured learning activities, often directly tied to clinical or patient-care-relevant content.

Question 112: On CT pulmonary angiography, a saddle embolus is identified. Where is this embolus located?

Straddling the main pulmonary artery bifurcation (Correct answer)
Left main pulmonary artery only
Right main pulmonary artery only
Within segmental pulmonary arteries bilaterally

Correct answer: Straddling the main pulmonary artery bifurcation

A saddle embolus straddles the bifurcation of the main pulmonary artery, occluding both left and right pulmonary arteries.

Question 113: Which factor primarily determines the z-axis (longitudinal) resolution in a multislice CT scanner?

kVp setting
Detector row width (Correct answer)
Reconstruction matrix size
Gantry rotation speed

Correct answer: Detector row width

Z-axis resolution is primarily determined by detector row width (collimation), which defines slice thickness in the longitudinal direction.

Question 114: What is homeostasis?

A type of cell division
An organ system
The body's ability to maintain stable internal conditions (Correct answer)
A disease state

Correct answer: The body's ability to maintain stable internal conditions

Homeostasis is the body's dynamic process of maintaining stable internal conditions (temperature, pH, blood sugar) despite external changes.

Question 115: A CT enterography protocol differs from a standard abdominal CT primarily in which way?

Use of oral contrast to distend the small bowel (Correct answer)
Intravenous contrast is not used
Higher tube current for better resolution
Scanning only the large intestine

Correct answer: Use of oral contrast to distend the small bowel

CT enterography uses large volumes of neutral oral contrast (e.g., VoLumen) to distend and visualize the small bowel mucosa.

Question 116: Aliasing artifacts in CT, which appear as fine streaks or Moiré patterns, are caused by which factor?

Excessive patient size
Incorrect table speed
High kVp settings
Insufficient detector sampling (Correct answer)

Correct answer: Insufficient detector sampling

Aliasing artifacts occur when the object being imaged contains spatial frequencies higher than the detector sampling rate can capture, per the Nyquist theorem.

Question 117: Windowing in CT (setting window width and level) affects:

Only the display of contrast by mapping HU values to gray shades (Correct answer)
Radiation dose to the patient
The actual CT numbers in the reconstructed data
The spatial resolution of the image

Correct answer: Only the display of contrast by mapping HU values to gray shades

Windowing is a display operation that maps selected HU ranges to the visible gray scale; it does not alter the underlying image data.

Question 118: A CT image shows ring artifacts. The MOST likely cause is:

Incorrect kVp selection
Too low an mAs setting
A malfunctioning or miscalibrated detector element (Correct answer)
Patient motion during scanning

Correct answer: A malfunctioning or miscalibrated detector element

Ring artifacts appear as circular bands centered on the isocenter and are caused by a single detector element producing consistently incorrect readings.

Question 119: A technologist reconstructs axial CT images with 5 mm thickness then reforms sagittal images showing 'staircase' appearance. The BEST solution is:

Reconstruct using thinner overlapping slices before reformatting (Correct answer)
Increase mAs for the next scan
Use a sharper reconstruction kernel
Increase the reconstruction FOV

Correct answer: Reconstruct using thinner overlapping slices before reformatting

Staircase artifact on reformats results from thick axial slices; reconstructing thinner overlapping slices provides finer z-axis sampling and smoother multiplanar reformats.

Question 120: A patient with a cardiac pacemaker presents for chest CT. Which artifact should the technologist anticipate?

Cupping artifact
Windmill artifact
Metallic streak artifact from the pacemaker leads and generator (Correct answer)
Ring artifact

Correct answer: Metallic streak artifact from the pacemaker leads and generator

Pacemaker generators and leads are highly attenuating metallic objects that produce characteristic beam hardening streak artifacts on chest CT.

Question 121: Which professional organization co-sponsors ARRT's Standards of Ethics alongside the Society of Radiologic Technologists?

American Medical Association
American Society of Radiologic Technologists (ASRT) (Correct answer)
Joint Commission on Allied Health Personnel in Ophthalmology
American College of Radiology

Correct answer: American Society of Radiologic Technologists (ASRT)

ARRT developed its Standards of Ethics in collaboration with the American Society of Radiologic Technologists (ASRT), the primary professional association for RT professionals.

Question 122: On axial CT of the pelvis, the obturator internus muscle is best identified by its location:

Lining the lateral wall of the true pelvis adjacent to the obturator foramen (Correct answer)
Between the iliacus and psoas muscles in the iliac fossa
Anterior to the pubic symphysis forming the pelvic floor
Posterior to the sacrum in the gluteal region

Correct answer: Lining the lateral wall of the true pelvis adjacent to the obturator foramen

The obturator internus lines the lateral wall of the true pelvis, arising from the inner surface of the obturator foramen.

Question 123: What is the primary purpose of the CT dose index (CTDI)?

To characterize radiation output of a CT scanner independent of patient size (Correct answer)
To measure patient absorbed dose in a single organ
To determine scatter radiation levels in the control room
To calculate the effective dose to the technologist

Correct answer: To characterize radiation output of a CT scanner independent of patient size

CTDI characterizes the radiation output of a CT scanner and allows standardized comparison between scanners and protocols.

Question 124: A pregnant patient requires urgent abdominal CT. What is the approximate threshold fetal dose below which deterministic effects (e.g., malformations) are considered negligible?

50 mGy (Correct answer)
100 mGy
5 mGy
500 mGy

Correct answer: 50 mGy

Below approximately 50 mGy, deterministic effects such as malformations or growth retardation are not expected; however, stochastic risk remains and dose should be minimized.

Question 125: How does ARRT define 'structured education' for CT post-primary eligibility?

Any on-the-job training logged by the supervisor
Self-study using any radiology textbook
Attendance at a single CT conference or symposium
Formal coursework covering specific CT content areas as defined by ARRT (Correct answer)

Correct answer: Formal coursework covering specific CT content areas as defined by ARRT

ARRT requires formal coursework in specific CT content areas as part of its structured education requirement for post-primary eligibility.

Question 126: Which CT finding most reliably indicates complicated acute pancreatitis?

Pancreatic necrosis (non-enhancing parenchyma) (Correct answer)
Peripancreatic fat stranding
Pancreatic enlargement
Peripancreatic fluid collections

Correct answer: Pancreatic necrosis (non-enhancing parenchyma)

Pancreatic necrosis, identified as non-enhancing parenchyma after IV contrast, is the defining feature of necrotizing pancreatitis.

Question 127: Which of the following correctly defines 'effective dose' (E) in radiation protection?

The absorbed dose to a single organ multiplied by the quality factor
The total energy deposited in the patient during a CT scan
The dose measured at the surface of a standard phantom
The weighted sum of equivalent doses to all irradiated tissues, reflecting overall stochastic risk (Correct answer)

Correct answer: The weighted sum of equivalent doses to all irradiated tissues, reflecting overall stochastic risk

Effective dose uses tissue weighting factors to sum equivalent doses across organs, yielding a single value (in mSv) that represents whole-body stochastic risk.

Question 128: A patient arrives for a radiographic exam and states they are allergic to iodine. Which action should the radiologic technologist take FIRST?

Administer prophylactic antihistamines
Cancel the exam without further action
Notify the radiologist or ordering physician immediately (Correct answer)
Proceed with non-contrast imaging only

Correct answer: Notify the radiologist or ordering physician immediately

The radiologist or ordering physician must be notified immediately so they can determine the appropriate course of action, including whether premedication is needed.

Question 129: Which financial benefit is most commonly associated with passing the ARRT CT certification exam for staff technologists?

Permanent exemption from performance reviews
Free continuing education paid by ARRT
Eligibility for a certification differential or bonus pay (Correct answer)
Automatic promotion to radiologist

Correct answer: Eligibility for a certification differential or bonus pay

Many hospitals and imaging facilities offer a certification differential—extra hourly pay or a one-time bonus—when staff earn specialty credentials.

Question 130: What does CT stand for in medical imaging?

Clinical Therapy
Central Treatment
Cardiac Testing
Computed Tomography (Correct answer)

Correct answer: Computed Tomography

CT (Computed Tomography) uses X-ray technology and computer processing to create detailed cross-sectional images of the body.

Question 131: Which of the following is an example of a breach of patient confidentiality?

Discussing a patient's case with a family member without patient consent (Correct answer)
Confirming a patient's identity before beginning a procedure
Documenting contrast administration in the patient's chart
Sharing patient imaging results with the ordering physician

Correct answer: Discussing a patient's case with a family member without patient consent

Under HIPAA, patient health information may not be shared with family members without the patient's explicit consent, except in specific circumstances.

Question 132: What is the window level and window width on CT images?

Patient positioning parameters
Scan speed controls
Physical measurements of the CT scanner
Settings that control the brightness and contrast of displayed images (Correct answer)

Correct answer: Settings that control the brightness and contrast of displayed images

Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).

Question 133: The window level (WL) in CT display refers to:

The minimum threshold for bone segmentation
The reconstruction matrix size
The total range of Hounsfield units shown
The center Hounsfield unit value of the displayed grayscale range (Correct answer)

Correct answer: The center Hounsfield unit value of the displayed grayscale range

Window level sets the midpoint of the HU range being displayed, determining which tissue densities appear as medium gray on the monitor.

Question 134: A CT technologist is audited by ARRT and cannot produce records for completed CE activities. What is the most likely consequence?

ARRT will contact the CE sponsors on their behalf
Their CE credits may be disallowed and registration revoked (Correct answer)
A formal written warning is issued
They are required to repeat the certification exam

Correct answer: Their CE credits may be disallowed and registration revoked

During an audit, failure to document CE activities can result in disallowance of credits and potential revocation of registration.

Question 135: A patient states, 'I am Jehovah's Witness and refuse any blood transfusion.' The radiologic technologist should:

Disregard the statement as the patient may not understand their condition
Contact the patient's family to override the decision
Document the statement and notify the supervising clinician immediately (Correct answer)
Proceed with the procedure and allow physicians to decide later

Correct answer: Document the statement and notify the supervising clinician immediately

A competent adult patient has the right to refuse treatment; the technologist must document this and notify the care team to ensure informed refusal is properly handled.

Question 136: The ARRT Standards of Ethics is incorporated into the CT certification process primarily to:

Ensure candidates demonstrate professional integrity and moral character (Correct answer)
Confirm candidates' insurance coverage
Verify candidates' financial standing
Assess candidates' academic GPA

Correct answer: Ensure candidates demonstrate professional integrity and moral character

The Standards of Ethics screening ensures that only individuals with demonstrated professional integrity are certified.

Question 137: What is a SITREP?

A supply request
An intelligence brief
A training exercise
A situation report providing current status to command (Correct answer)

Correct answer: A situation report providing current status to command

SITREP (Situation Report) provides commanders with timely information about the current operational situation.

Question 138: A radiologic technologist notices that CT images of the liver appear uniformly noisy despite using standard mAs. The MOST appropriate first corrective action is:

Reduce the reconstruction FOV by 50%
Verify that the correct reconstruction kernel and algorithm are applied (Correct answer)
Double the mAs for the repeat scan immediately
Switch to a narrower window width for display

Correct answer: Verify that the correct reconstruction kernel and algorithm are applied

Verifying protocol settings (kernel, algorithm, slice thickness) first ensures the source of apparent noise is identified before unnecessarily increasing dose.

Question 139: Partial volume averaging artifact in CT is BEST minimized by:

Decreasing the tube current
Using a smoother reconstruction kernel
Increasing the reconstruction matrix
Using thinner slice collimation (Correct answer)

Correct answer: Using thinner slice collimation

Thinner slices reduce the z-axis extent of each voxel, decreasing the chance that multiple tissue types are averaged into a single voxel.

Question 140: When creating coronal MPR images from a helical chest CT, image quality is best when the original acquisition used:

Thick slices (5–10 mm) reconstructed at 5 mm intervals
Thin slices (≤1 mm) reconstructed at overlapping intervals (0.5–0.7 mm) (Correct answer)
Large FOV and minimal overlap
High pitch with standard soft tissue kernel only

Correct answer: Thin slices (≤1 mm) reconstructed at overlapping intervals (0.5–0.7 mm)

Thin, overlapping reconstructions produce near-isotropic voxels that allow high-quality coronal and sagittal reformations without visible stair-step artifacts.

Question 141: The 'cupping artifact' in CT, where the center of a uniform object appears less dense than its periphery, is a manifestation of which phenomenon?

Partial volume averaging
Quantum noise
Beam hardening (Correct answer)
Aliasing

Correct answer: Beam hardening

Cupping artifact is a form of beam hardening where the edges of the object appear brighter because the beam hardens less traveling a shorter path length.

Question 142: Which post-processing technique is most appropriate for evaluating luminal stenosis of the carotid arteries on a CT angiogram?

Standard axial images only
Volume rendering alone
Multiplanar reformation combined with MIP (Correct answer)
Minimum intensity projection (MinIP)

Correct answer: Multiplanar reformation combined with MIP

Combining MPR (which shows vessel walls and plaques in cross-section) with MIP (which shows the lumen in projection) gives the most complete assessment of carotid stenosis.

Question 143: What is the primary purpose of the portal venous phase in a multiphasic liver CT protocol?

To detect hypervascular lesions at peak arterial enhancement
To demonstrate maximum enhancement of the liver parenchyma for lesion detection (Correct answer)
To assess the early arterial supply to renal tumors
To evaluate the hepatic veins and biliary ducts exclusively

Correct answer: To demonstrate maximum enhancement of the liver parenchyma for lesion detection

The portal venous phase (approximately 60–70 seconds post-injection) provides peak liver parenchymal enhancement, optimizing detection of hypovascular metastases.

Question 144: Which pancreatic landmark on CT imaging marks the junction between the head and body of the pancreas?

The splenic artery origin from the celiac axis
The main pancreatic duct (duct of Wirsung)
The superior mesenteric vein crossing the pancreas (Correct answer)
The common bile duct entering the pancreatic head

Correct answer: The superior mesenteric vein crossing the pancreas

The superior mesenteric vein crosses the anterior surface of the pancreas at the junction of the head and body.

Question 145: Which of the following contrast media reactions is classified as a severe (anaphylactoid) reaction requiring immediate intervention?

Nausea without vomiting
Mild urticaria (hives) with no other symptoms
Warm flushing sensation at the injection site
Bronchospasm with hypotension (Correct answer)

Correct answer: Bronchospasm with hypotension

Bronchospasm with hypotension constitutes a severe anaphylactoid reaction that requires immediate administration of epinephrine and emergency support.

Question 146: What is the correct order for donning PPE?

Any order is acceptable
Gloves, gown, mask, eye protection
Gown, mask, eye protection, gloves (Correct answer)
Mask, gloves, gown, eye protection

Correct answer: Gown, mask, eye protection, gloves

The correct donning sequence is gown first, then mask/respirator, eye protection/face shield, and gloves last. This prevents contamination during application.

Question 147: Which of the following CE topics would be MOST directly relevant to CT recertification requirements?

Fluoroscopy guided interventional procedures
MRI safety screening protocols
Ultrasound transducer maintenance
Advances in CT radiation dose reduction techniques (Correct answer)

Correct answer: Advances in CT radiation dose reduction techniques

CE focused on CT-specific topics like dose reduction directly supports the knowledge base required for CT certification maintenance.

Question 148: What is the NATO phonetic alphabet letter for 'B'?

Beta
Boy
Bravo (Correct answer)
Baker

Correct answer: Bravo

In the NATO phonetic alphabet, 'B' is represented by 'Bravo.' This ensures clear radio communication.

Question 149: On axial CT of the chest at the level of the aortic root, the right ventricle is identified by its characteristic location:

Between the right atrium and pulmonary trunk
Posterior to the left atrium
Posterior and leftward, forming the cardiac apex
Anterior and rightward, forming the anterior cardiac border (Correct answer)

Correct answer: Anterior and rightward, forming the anterior cardiac border

The right ventricle is the most anterior cardiac chamber and forms the anterior cardiac border on axial CT at the level of the aortic root.

Question 150: An employer lists 'ARRT(CT)' as a preferred qualification in a job posting. What does this abbreviation signify?

Certification by the American College of Tomography
Completion of a CT vendor-specific training course
ARRT registered with CT post-primary certification (Correct answer)
The applicant holds a general radiology license only

Correct answer: ARRT registered with CT post-primary certification

ARRT(CT) denotes that an individual holds ARRT registration and has passed the CT post-primary certification examination.

Question 151: Which CT image quality parameter is measured using a modulation transfer function (MTF)?

Contrast resolution
Spatial resolution (Correct answer)
Temporal resolution
Noise power spectrum

Correct answer: Spatial resolution

The MTF quantifies spatial resolution by describing how faithfully the CT system reproduces objects of varying spatial frequencies.

Question 152: The dose length product (DLP) is calculated by multiplying CTDI_vol by which parameter?

Number of detector rows
Scan length (cm) (Correct answer)
Rotation time
Pitch factor

Correct answer: Scan length (cm)

DLP = CTDI_vol × scan length (cm), providing a single value that reflects the total radiation energy deposited during the scan.

Question 153: What is the primary radiation hazard associated with CT compared to conventional radiography?

Significantly greater patient dose due to multiple rotational acquisitions and extended scan volumes (Correct answer)
Use of radioactive isotopes as contrast agents
Greater secondary radiation reaching personnel in adjacent rooms
Higher peak kilovoltage

Correct answer: Significantly greater patient dose due to multiple rotational acquisitions and extended scan volumes

CT delivers substantially higher patient doses than conventional radiography because it involves multiple rotational X-ray acquisitions covering large anatomical volumes.

Question 154: Which CT quality control phantom is most commonly used to evaluate CT number accuracy, noise, uniformity, and spatial resolution?

Leeds TOR phantom
MOSFET dosimetry phantom
Alderson Rando phantom
AAPM CT performance phantom (Correct answer)

Correct answer: AAPM CT performance phantom

The AAPM CT performance phantom contains inserts for testing multiple image quality parameters including HU accuracy, noise, and spatial resolution.

Question 155: What is a nosocomial infection?

An infection acquired in a healthcare facility (Correct answer)
A childhood disease
A respiratory infection
A genetic condition

Correct answer: An infection acquired in a healthcare facility

Nosocomial (healthcare-associated) infections are acquired during the course of receiving medical treatment in a healthcare facility, not present at admission.

Question 156: What is the purpose of an emergency action plan?

To assign parking spaces
To manage budgets
To schedule daily activities
To establish procedures for responding to various emergencies (Correct answer)

Correct answer: To establish procedures for responding to various emergencies

Emergency action plans outline specific procedures for different emergency scenarios, ensuring organized, efficient response that protects personnel.

Question 157: On axial CT at the level of the pelvis, the external iliac artery is located relative to the external iliac vein in which position?

Lateral to the vein
Posterior to the vein
Medial to the vein
Anterior and medial to the vein (Correct answer)

Correct answer: Anterior and medial to the vein

The external iliac artery lies anteromedial to the external iliac vein along the pelvic brim.

Question 158: On axial CT of the neck, the hypopharynx is best visualized at which vertebral level?

C1-C2
C3-C4
C4-C6 (Correct answer)
C7-T1

Correct answer: C4-C6

The hypopharynx extends from the level of the hyoid bone (C3) to the cricopharyngeus muscle (C6), and is best visualized on CT at C4-C6.

Question 159: Increasing the CT reconstruction matrix from 512×512 to 1024×1024 while keeping FOV constant will:

Increase pixel size and reduce spatial resolution
Reduce scan time
Decrease pixel size and potentially improve spatial resolution (Correct answer)
Decrease image noise

Correct answer: Decrease pixel size and potentially improve spatial resolution

Doubling the matrix halves the pixel size (FOV/matrix), which can improve displayed spatial resolution but also increases image noise and data storage requirements.

Question 160: CT calcium scoring of the coronary arteries uses which post-processing method to quantify calcification?

Subtraction of non-contrast from contrast images
MIP projection over the cardiac cycle
Volume rendering with opacity mapping
Agatston scoring based on lesion area and peak Hounsfield unit density (Correct answer)

Correct answer: Agatston scoring based on lesion area and peak Hounsfield unit density

Agatston scoring multiplies the area of each calcified lesion by a density factor based on peak HU (1–4 scale), then sums all lesions to yield the total calcium score.

Question 161: Minimum intensity projection (MinIP) post-processing is particularly useful for displaying which anatomical structures?

Dense bone and calcifications
Air-filled airways and lung parenchyma (Correct answer)
Contrast-enhanced blood vessels
Solid abdominal organs

Correct answer: Air-filled airways and lung parenchyma

MinIP projects the lowest attenuation voxel along each ray, making it ideal for displaying air-containing structures like the tracheobronchial tree or emphysematous lung.

Question 162: Which technique is most commonly used to reduce metal artifact in CT imaging of patients with hip prostheses?

Increasing slice thickness
Using a smaller FOV
Decreasing kVp
Metal artifact reduction (MAR) software (Correct answer)

Correct answer: Metal artifact reduction (MAR) software

Metal artifact reduction (MAR) algorithms replace corrupted projection data near metal with interpolated data, significantly reducing streaking artifacts.

Question 163: In CT colonography (virtual colonoscopy), which type of contrast material is used to 'tag' residual stool and fluid?

Rectal gadolinium solution
Oral barium and/or dilute iodinated contrast ingested before the exam (Correct answer)
CO2 gas instilled into the colon
IV iodinated contrast to enhance the colonic mucosa

Correct answer: Oral barium and/or dilute iodinated contrast ingested before the exam

Fecal tagging uses oral barium and/or iodinated contrast ingested in the days before CTC to label residual stool and fluid, allowing software subtraction.

Question 164: On a CT KUB (kidneys, ureters, bladder), which stone type appears LEAST dense (lowest Hounsfield units)?

Calcium oxalate monohydrate
Struvite
Uric acid (Correct answer)
Cystine

Correct answer: Uric acid

Uric acid stones are the least dense urinary calculi on CT (100–400 HU), compared to calcium-based stones which exceed 800 HU.

Question 165: Respiratory motion artifacts on chest CT can best be minimized by:

Increasing slice thickness
Using breath-hold technique during acquisition (Correct answer)
Increasing kVp
Widening the display window

Correct answer: Using breath-hold technique during acquisition

Instructing the patient to suspend respiration during CT acquisition eliminates breathing motion, preventing blurring and step artifacts in the chest.

Question 166: A radiographer whose ARRT credential has lapsed for more than 2 years wishes to apply for CT certification. What must they do first?

Complete a CT-only refresher course
Apply directly for CT without reinstating
Submit a waiver request to ARRT
Reinstate the primary credential to active unrestricted status (Correct answer)

Correct answer: Reinstate the primary credential to active unrestricted status

A lapsed primary credential must be fully reinstated to active unrestricted status before CT post-primary eligibility is granted.

Question 167: Which statement best describes an isotropic voxel in CT imaging?

A voxel with equal dimensions in x, y, and z axes (Correct answer)
A voxel that contains only one tissue type
A voxel reconstructed using iterative algorithms
A voxel with maximum attenuation value

Correct answer: A voxel with equal dimensions in x, y, and z axes

Isotropic voxels have equal measurements in all three spatial dimensions, enabling high-quality MPR and 3D reconstructions in any plane without stair-step degradation.

Question 168: What prerequisite must a radiologic technologist fulfill before sitting for the ARRT CT certification examination?

Completing a two-year CT fellowship program
Holding a current ARRT primary certification and meeting CT clinical experience requirements (Correct answer)
Obtaining approval from the state radiologic technology board
Passing the American Board of Radiology oral examination

Correct answer: Holding a current ARRT primary certification and meeting CT clinical experience requirements

Candidates must hold a current ARRT primary certification and document the required number of CT clinical procedures before applying for the CT post-primary exam.

Question 169: A patient has a Foley catheter in place. When transferring this patient, the urinary drainage bag should be positioned:

Clamped during all transfers to avoid spillage
Above the level of the bladder to maintain drainage
Below the level of the bladder to prevent backflow (Correct answer)
Disconnected temporarily during the move

Correct answer: Below the level of the bladder to prevent backflow

The drainage bag must remain below bladder level at all times to use gravity for urine drainage and prevent backflow that could cause infection.

Question 170: What is the primary purpose of the bow-tie filter in a CT scanner?

Increase tube current
Compensate for the cylindrical shape of patients to reduce peripheral dose (Correct answer)
Remove scatter radiation from the detector
Calibrate the detector array

Correct answer: Compensate for the cylindrical shape of patients to reduce peripheral dose

The bow-tie (wedge) filter shapes the beam so less radiation hits the thinner periphery of the patient, reducing dose and preventing detector saturation.

Question 171: The windmill artifact in multislice CT helical acquisitions is MOST pronounced when:

High kVp is used with thin collimation
Small FOV is selected with fine matrix
High pitch values are combined with thick slice reconstruction (Correct answer)
Low mAs is used with a smooth kernel

Correct answer: High pitch values are combined with thick slice reconstruction

Windmill artifact stems from undersampling in the z-direction; it is most visible with high pitch (sparse data) and thick reconstructions that exaggerate interpolation errors.

Question 172: To meet ARRT’s ethics requirements, which of the following is necessary?

Submit a personal statement of professional ethics
Pass a background check and provide character references
Agree to follow the ARRT Standards of Ethics and report any potential violations (Correct answer)
Take a separate ethics exam during the certification process

Correct answer: Agree to follow the ARRT Standards of Ethics and report any potential violations

The ARRT places a strong emphasis on ethical conduct within the radiologic technology profession. To meet their ethics requirements, candidates must formally agree to adhere to the ARRT Standards of Ethics, which outline professional responsibilities and conduct. This commitment includes reporting any potential violations, upholding the integrity of the profession.

Question 173: What is homeostasis?

A disease state
The body's ability to maintain stable internal conditions (Correct answer)
A type of cell division
An organ system

Correct answer: The body's ability to maintain stable internal conditions

Homeostasis is the body's dynamic process of maintaining stable internal conditions (temperature, pH, blood sugar) despite external changes.

Question 174: The pitch value in helical CT is defined as:

Slice thickness divided by detector row width
Table travel per rotation divided by total beam collimation width (Correct answer)
Gantry rotation speed divided by table speed
kVp divided by mA

Correct answer: Table travel per rotation divided by total beam collimation width

Pitch = table distance traveled per 360° rotation ÷ total collimated beam width, and values >1 indicate gaps in data coverage.

Question 175: What are the four basic tissue types in the human body?

Brain, heart, lung, and liver
Epithelial, connective, muscle, and nervous (Correct answer)
Skin, bone, blood, and fat
Smooth, rough, dense, and loose

Correct answer: Epithelial, connective, muscle, and nervous

The four fundamental tissue types are epithelial (covering/lining), connective (support/connection), muscle (movement), and nervous (communication/control).

Question 176: In CT, iterative reconstruction (IR) algorithms primarily allow dose reduction by:

Eliminating beam hardening artifacts entirely
Producing diagnostic-quality images at lower mAs settings than filtered back projection (Correct answer)
Reducing the number of detector rows required
Increasing spatial resolution without any dose penalty

Correct answer: Producing diagnostic-quality images at lower mAs settings than filtered back projection

Iterative reconstruction models image noise mathematically, allowing lower mAs protocols to produce acceptable image quality compared to filtered back projection.

Question 177: Which of the following is the primary reason for using a low-osmolar, non-ionic iodinated contrast agent for intravenous CT contrast?

It significantly reduces the risk of adverse reactions compared to ionic agents (Correct answer)
It requires a lower injection rate
It is less expensive than ionic contrast
It provides higher iodine concentration per mL

Correct answer: It significantly reduces the risk of adverse reactions compared to ionic agents

Non-ionic, low-osmolar contrast agents have a much lower rate of adverse reactions (including severe reactions) compared to older high-osmolar ionic agents.

Question 178: A CT chest post-lobectomy shows a new fluid collection with an air-fluid level adjacent to the bronchial stump. What complication does this suggest?

Pleural effusion
Normal post-operative change
Bronchopleural fistula with empyema (Correct answer)
Pulmonary edema

Correct answer: Bronchopleural fistula with empyema

An air-fluid level adjacent to a bronchial stump indicates bronchopleural fistula, allowing air to enter the pleural space, often with secondary empyema.

Question 179: Which employment sector has seen the fastest growth in demand for ARRT CT-certified technologists in recent years?

Outpatient and freestanding imaging centers (Correct answer)
Veterinary imaging clinics
Film-based radiology departments
Dental radiography offices

Correct answer: Outpatient and freestanding imaging centers

The rapid expansion of outpatient and freestanding imaging centers has driven increased demand for ARRT CT-certified technologists outside traditional hospital settings.

Question 180: What is the purpose of an After Action Review (AAR)?

To analyze what happened, why, and how to improve (Correct answer)
To assign blame
To plan the next mission only
To write performance reviews

Correct answer: To analyze what happened, why, and how to improve

AARs are structured reviews analyzing what was planned, what happened, why there were differences, and what can be improved.

Question 181: What are the four basic tissue types in the human body?

Skin, bone, blood, and fat
Brain, heart, lung, and liver
Smooth, rough, dense, and loose
Epithelial, connective, muscle, and nervous (Correct answer)

Correct answer: Epithelial, connective, muscle, and nervous

The four fundamental tissue types are epithelial (covering/lining), connective (support/connection), muscle (movement), and nervous (communication/control).

Question 182: When a CT abdomen protocol specifies 'nephrographic phase,' scanning typically occurs at what delay after IV contrast injection?

15–25 seconds
80–120 seconds (Correct answer)
5–10 minutes
30–45 seconds

Correct answer: 80–120 seconds

The nephrographic phase occurs at approximately 80–120 seconds post-injection when both cortex and medulla enhance uniformly, optimizing renal parenchymal visualization.

Question 183: Within what timeframe must newly certified CT technologists complete their first renewal cycle?

When their primary registration expires (Correct answer)
Two years from certification date
One year from certification date
Three years from certification date

Correct answer: When their primary registration expires

Post-primary certification renewal is typically aligned with the technologist's primary registration renewal date, not a separate independent cycle.

Question 184: Which artifact appears as a dark band between two high-density objects on a CT image and is caused by beam hardening?

Windmill artifact
Ring artifact
Moiré artifact
Shadowing or 'dark band' artifact (Correct answer)

Correct answer: Shadowing or 'dark band' artifact

Dark bands (also called 'shadowing' or 'cupping' between dense objects) arise from extreme beam hardening where few low-energy photons survive to reach the detector between two dense structures.

Question 185: What is the role of the ARRT Standards of Ethics in the recertification process?

They define conduct requirements that technologists must uphold to maintain certification (Correct answer)
They establish the minimum number of CE hours above 24
They determine the passing score for the CT exam
They set minimum clinical hours for renewal

Correct answer: They define conduct requirements that technologists must uphold to maintain certification

The ARRT Standards of Ethics outline the professional and personal conduct required for technologists to maintain good standing and certification.

Question 186: Multiplanar reformation (MPR) in CT refers to:

Applying color to CT images based on Hounsfield units
Generating 3D surface models from volumetric data
Subtracting pre-contrast from post-contrast images
Reconstructing axial images into coronal, sagittal, or oblique planes (Correct answer)

Correct answer: Reconstructing axial images into coronal, sagittal, or oblique planes

MPR uses the volumetric CT dataset to create reformatted images in any anatomical plane without additional radiation exposure to the patient.

Question 187: Which of the following is NOT an acceptable method for documenting completed CE credits with ARRT?

Submitting certificates directly to ARRT upon renewal
Having the approved sponsor report credits to ARRT directly
Online entry through the ARRT website
Verbal confirmation from a supervisor (Correct answer)

Correct answer: Verbal confirmation from a supervisor

ARRT requires verifiable documentation of CE credits; verbal confirmation from a supervisor is not an accepted method.

Question 188: On axial CT at the level of L4-L5, which structure is found anterior to the vertebral body?

Inferior mesenteric artery origin
Celiac axis
Superior mesenteric artery origin
Abdominal aortic bifurcation (Correct answer)

Correct answer: Abdominal aortic bifurcation

The abdominal aorta bifurcates into the common iliac arteries at approximately the L4 vertebral level.

Question 189: CT colonoscopy (virtual colonoscopy) relies on which post-processing technique to create a simulated fly-through view of the colon lumen?

Subtraction imaging
Maximum intensity projection
Volume rendering with endoluminal navigation (Correct answer)
Minimum intensity projection

Correct answer: Volume rendering with endoluminal navigation

Volume rendering with endoluminal navigation uses the air-distended colon as a flight path, generating a simulated colonoscopic perspective of the mucosal surface.

Question 190: A CT pelvis shows a complex ovarian mass with solid components, calcifications, fat density, and hair-like structures. This is most consistent with:

Serous cystadenocarcinoma
Endometrioma
Mature cystic teratoma (dermoid cyst) (Correct answer)
Mucinous cystadenoma

Correct answer: Mature cystic teratoma (dermoid cyst)

Mature cystic teratomas contain fat, calcium, and soft tissue elements (including teeth or hair) from multiple germ cell layers.

Question 191: Which of the following scan parameters most directly affects the z-axis (longitudinal) spatial resolution in CT?

Field of view (FOV)
Window width
Matrix size
Slice thickness (Correct answer)

Correct answer: Slice thickness

Slice thickness determines the size of the voxel in the z-direction and therefore directly controls longitudinal (through-plane) spatial resolution.

Question 192: Which of the following BEST describes noise power spectrum (NPS) in CT?

The ratio of signal to total detector noise
A test of detector linearity across HU ranges
A measure of how noise is distributed across spatial frequencies in an image (Correct answer)
The standard deviation of HU values in a uniform phantom

Correct answer: A measure of how noise is distributed across spatial frequencies in an image

NPS characterizes the frequency content of image noise, showing whether noise is more granular (high-frequency) or blotchy (low-frequency) depending on reconstruction parameters.

Question 193: A candidate applies for CT certification under the structured education pathway. Which type of program must they have completed?

A CT-specific structured education program accredited by a recognized body (Correct answer)
Any radiology-related online course
A self-designed independent study program
A hospital orientation program

Correct answer: A CT-specific structured education program accredited by a recognized body

The structured education pathway requires completion of a CT program accredited by a body recognized by ARRT, such as JRCERT.

Question 194: A traveling radiologic technologist wants to maximize placement opportunities across the country. Which credential most broadly enhances CT assignment eligibility?

A local hospital's internal CT competency checklist
State-specific CT operator permit from one state only
ARRT CT post-primary certification recognized by travel staffing agencies nationwide (Correct answer)
A vendor training certificate from a single CT manufacturer

Correct answer: ARRT CT post-primary certification recognized by travel staffing agencies nationwide

Travel staffing agencies and their client facilities consistently recognize ARRT CT certification as the standard credential for CT assignment eligibility across the US.

ARRT Computed Tomography (CT) Certification Examination

The ARRT CT certification exam assesses entry-level knowledge and cognitive skills required for computed tomography practice, covering patient care, radiation safety, image production, and CT imaging procedures across all major anatomical regions.

195

Questions

180 min

Time Limit

75%

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