Radiography Exam Digital Radiography and PACS

Question 1

In computed radiography (CR), the image is captured by a photostimulable phosphor (PSP) plate. To read the image, the PSP plate is exposed to:

Accepted Answer

A laser beam that stimulates the stored energy to emit visible light

Answer

A high-voltage electric field

Answer

Ultraviolet light

Answer

A second x-ray exposure

Question 2

Direct digital radiography (DR) flat panel detectors using amorphous selenium (a-Se) are classified as:

Accepted Answer

Direct conversion detectors (x-rays directly produce electrical charge)

Answer

Indirect conversion detectors (x-rays produce light, then electrical charge)

Answer

Photostimulable phosphor detectors

Answer

Computed tomography detectors

Question 3

In digital radiography, the exposure index (EI) number primarily reflects:

Accepted Answer

The amount of radiation exposure received by the image detector

Answer

The mAs used for the exposure

Answer

The kVp selected for the technique

Answer

The SID used during the exposure

Question 4

PACS (Picture Archiving and Communication System) uses which standard protocol for storing, transmitting, and displaying medical images?

Accepted Answer

DICOM (Digital Imaging and Communications in Medicine)

Answer

HL7 (Health Level 7)

Answer

JPEG 2000

Answer

PDF

Question 5

The primary advantage of using indirect conversion flat panel detectors with cesium iodide (CsI:Tl) over gadolinium oxysulfide (GOS) screens is:

Accepted Answer

CsI:Tl has a needle-like crystal structure that channels light to the detector, reducing light spreading and improving spatial resolution

Answer

CsI:Tl requires less radiation dose

Answer

CsI:Tl is more resistant to humidity

Answer

CsI:Tl produces more light per x-ray photon

Question 6

Detective quantum efficiency (DQE) in digital radiography describes:

Accepted Answer

How efficiently the detector converts x-ray exposure into a useful signal relative to ideal detector performance

Answer

The number of pixels per square millimeter in the detector

Answer

The maximum dose the detector can receive before saturation

Answer

The speed at which the detector reads out the image