CRI Image Quality & Artifacts 2

Question 1

Which artifact appears as a bright linear streak on a radiograph when a high-density object is present in the beam path of a CT scanner?

Accepted Answer

Beam hardening streak

Answer

Beam hardening streaks occur when polychromatic X-rays pass through dense objects like metal implants, causing low-energy photons to be preferentially absorbed and producing bright linear artifacts.

Question 2

What term describes the minimum detectable flaw size in a radiographic inspection, often expressed as a percentage of material thickness?

Accepted Answer

Sensitivity

Answer

Radiographic sensitivity is the smallest detectable discontinuity size, commonly expressed as 2% of material thickness for acceptable industrial inspections.

Question 3

A radiograph shows a diffuse, foggy appearance across the entire image without exposure to the primary beam. What is the most likely cause?

Accepted Answer

Radiation fog from scatter or secondary exposure

Answer

Background or radiation fog results from stray scatter radiation, leaky cassettes, or film exposed to secondary radiation before or after primary exposure.

Question 4

In digital radiography, what is the primary purpose of a flat-field correction?

Accepted Answer

To compensate for non-uniform detector response and sensitivity

Answer

Flat-field correction normalizes pixel response across the detector panel, compensating for variations in detector element sensitivity and beam intensity distribution.

Question 5

Which factor has the GREATEST influence on reducing geometric unsharpness in radiography?

Accepted Answer

Increasing source-to-object distance (SOD)

Answer

Increasing SOD reduces geometric unsharpness (Ug) because Ug = f × OFD/SOD, so a larger SOD directly decreases the penumbra effect.

(CRI) Certified Radiographic Interpreter Practice Test

(CRI) Certified Radiographic Interpreter Practice Test

CRI Image Quality & Artifacts 2