Radiologist experience effects on contrast detection.

Current literature shows that radiologist experience does not affect detection tasks when the object does not require medical training to detect. However, the research was never sufficiently detailed to examine if the contrast detection threshold is also the same for radiologists versus nonradiologists. Previously, contrast threshold research was performed predominantly on nonradiologists. Therefore, any differences could lead to over- or under-estimation of the performance capabilities of radiologists. Fourteen readers, evenly divided between radiologists and nonradiologists, read a set of 150 mammogram-like images. The study was performed with the location of the objects known and unknown, requiring two separate readings. No difference in the contrast detection threshold between reader groups for either the location-unknown (4.9 just noticeable differences) or location-known (3.3 just noticeable differences) images was seen. The standard deviation for the location-unknown condition had no difference (p 0.91). But for the location-known condition, a significant difference (p 0.0009) was seen between radiologists and nonradiologists. No difference in contrast detection based on reader experience was observed, but decreased variance was seen with radiologists in the location-known condition.