# Image Noise Analysis: Which Scanner Stands Out?

## Which scanner has the least amount of image noise based on the provided data?

A. Water phantom average = -0.5 HU, Water phantom standard deviation = 1.2, Line pairs = 12 lp/cm

B. Water phantom average = 1.0 HU, Water phantom standard deviation = 3.1, Line pairs = 14 lp/cm

C. Water phantom average = -11 HU, Water phantom standard deviation = 0.2, Line pairs = 13 lp/cm

D. Water phantom average = 2.0 HU, Water phantom standard deviation = 2.0, Line pairs = 10 lp/cm

Final answer: Scanner C

## Answer:

Scanner C, with a water phantom standard deviation of 0.2 HU, has the least amount of image noise among the options provided.

Explanation:

To determine which scanner has the least amount of image noise, we look at the standard deviation values that represent image noise levels in Hounsfield units (HU) from the water phantom tests. Lower standard deviation indicates less noise. If we compare the provided options, scanner C with a water phantom standard deviation of 0.2 HU has the least noise, significantly lower than the other scanners. Although the scanner has an average of -11 HU, which seems far from the expected 0 HU for water, the noise level is the concern here, not the accuracy of the average. Therefore, it's the standard deviation of the water phantom readings that matters for assessing noise. Other factors like line pairs per centimeter (lp/cm) affect the resolution but not necessarily the noise directly.