ARRT Radiography Practice Test
ARRT Image Acquisition & Evaluation Practice Questions
Image Acquisition & Evaluation makes up 7 of every 50 questions on a Tigertest ARRT practice test. Here are 10 of the 28 questions on it, each with the answer and the reason.
Updated by the Tigertest team. Based on the ARRT Radiography Examination Content Specifications. Original questions; 50 per test, weighted like the real exam. Not affiliated with ARRT.
1. A technique uses 300 mA and 0.05 second. What is the mAs?
- A.150 mAs
- B.15 mAs
- C.6 mAs
- D.60 mAs
Answer: B. mAs = mA x seconds: 300 x 0.05 = 15 mAs. 60 would come from treating 0.05 s as 0.2 s.
2. An exposure needs 25 mAs at 500 mA. What exposure time should be set?
- A.0.02 second
- B.0.005 second
- C.0.5 second
- D.0.05 second
Answer: D. Time = mAs / mA: 25 / 500 = 0.05 second. 0.5 second is ten times too long.
3. A knee needs 10 mAs at 40 inches SID. What mAs keeps receptor exposure the same at 72 inches?
- A.32.4 mAs
- B.3.09 mAs
- C.18 mAs
- D.5.6 mAs
Answer: A. Direct square law: new mAs = 10 x (72/40) squared = 10 x 3.24 = 32.4 mAs. 18 forgets to square the distance ratio.
4. A technique is 70 kVp at 20 mAs. Using the 15% rule, what mAs goes with 80 kVp?
- A.20 mAs
- B.5 mAs
- C.10 mAs
- D.40 mAs
Answer: C. Raising kVp by about 15% (70 to 80) roughly doubles receptor exposure, so halve the mAs to 10. 40 mAs would double it again.
5. A part needs 4 mAs without a grid. Using a 12:1 grid (conversion factor 5), what mAs is needed?
- A.48 mAs
- B.9 mAs
- C.20 mAs
- D.12 mAs
Answer: C. Multiply by the grid conversion factor: 4 x 5 = 20 mAs. 48 would wrongly multiply by the ratio itself.
6. A study uses 12 mAs with an 8:1 grid (factor 4). What mAs is needed with a 16:1 grid (factor 6)?
- A.18 mAs
- B.8 mAs
- C.72 mAs
- D.24 mAs
Answer: A. New mAs = 12 x 6/4 = 18 mAs. 24 assumes doubling the ratio doubles the mAs.
7. SID is 40 inches and SOD is 32 inches. What is the magnification factor?
- A.8
- B.0.8
- C.1.5
- D.1.25
Answer: D. Magnification factor = SID / SOD = 40 / 32 = 1.25. 0.8 is SOD / SID, inverted.
8. An object measures 6 cm on the image with a magnification factor of 1.25. What is its actual size?
- A.6.0 cm
- B.4.8 cm
- C.7.5 cm
- D.4.0 cm
Answer: B. Object size = image size / MF: 6 / 1.25 = 4.8 cm. Multiplying gives 7.5 cm, the wrong direction.
9. Which factor is the primary control of the number of photons reaching the receptor?
- A.OID
- B.mAs
- C.kVp
- D.Focal spot size
Answer: B. mAs directly controls x-ray quantity and so receptor exposure. kVp also affects it but mainly controls penetration and contrast.
10. Raising kVp while adjusting mAs to keep exposure the same produces an image with:
- A.More magnification
- B.Less spatial resolution
- C.Higher contrast
- D.Lower contrast
Answer: D. Higher kVp penetrates more evenly and adds Compton scatter, giving more shades of gray (lower contrast, longer scale).
Practice all 28 image acquisition & evaluation questions, and the rest of the 200-question bank, in the free ARRT training sets. Questions you miss come back until you have mastered them.
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