ARRT Thorax and Abdomen Procedures 3 — Questions and Answers
Question 1: When performing an AP projection of the chest on a supine trauma patient, how should the IR be positioned relative to the patient?
- Angled 5° caudad toward the feet
- Perpendicular to the long axis, centered at T7 (Correct answer)
- Perpendicular centered at the xiphoid
- Angled 15° cephalad
Correct answer: Perpendicular to the long axis, centered at T7
For a supine AP chest, the IR is centered at T7 with the central ray perpendicular to the IR to minimize distortion of the mediastinal structures.
Question 2: A patient with suspected right middle lobe pneumonia would be best evaluated with which additional view beyond the standard PA and lateral chest?
- Left anterior oblique
- Right anterior oblique (Correct answer)
- Apical lordotic
- Right lateral decubitus
Correct answer: Right anterior oblique
The right anterior oblique (RAO) rotates the right lung forward, separating the middle lobe from overlapping structures and improving its visualization.
Question 3: The AP axial (lordotic) projection of the chest is obtained by angling the central ray how many degrees cephalad when the patient stands upright?
- 5–10°
- 15–20° (Correct answer)
- 25–30°
- 35–40°
Correct answer: 15–20°
A 15–20° cephalad angle (or equivalent patient lean-back) projects the clavicles above the lung apices, revealing the apical lung zones.
Question 4: For an upper GI series, which position places the duodenal bulb in profile and best demonstrates a posterior duodenal ulcer?
- RAO
- LAO
- LPO
- Right lateral (Correct answer)
Correct answer: Right lateral
The right lateral position places the duodenal bulb in a true lateral projection, profiling the anterior and posterior walls to demonstrate posterior ulcers.
Question 5: On an AP abdomen (KUB) radiograph, which organ's shadow is normally visible in the right upper quadrant?
- Spleen
- Liver (hepatic shadow) (Correct answer)
- Left kidney
- Gallbladder
Correct answer: Liver (hepatic shadow)
The hepatic shadow (liver) is routinely visible as a homogeneous soft-tissue density occupying the right upper quadrant on an AP abdomen.
Question 6: A chest radiograph shows the trachea deviated to the left. Which condition is most likely responsible if the mediastinum is also shifted left?
- Right-sided pneumothorax
- Left-sided pleural effusion
- Left upper lobe collapse/atelectasis (Correct answer)
- Right lower lobe consolidation
Correct answer: Left upper lobe collapse/atelectasis
Left upper lobe collapse causes volume loss on the left, pulling the trachea and mediastinum toward the affected (left) side due to negative pressure.
Question 7: What SID (source-to-image distance) is standard for PA chest radiography to minimize cardiac magnification?
- 40 inches (102 cm)
- 48 inches (122 cm)
- 72 inches (183 cm) (Correct answer)
- 60 inches (152 cm)
Correct answer: 72 inches (183 cm)
A 72-inch SID is standard for PA chest radiographs; the increased distance reduces magnification of the heart and other thoracic structures.
ARRT Thorax and Abdomen Procedures 3
When performing an AP projection of the chest on a supine trauma patient, how should the IR be positioned relative to the patient?