Contrast enhancement: diagnostic significance from a statistical viewpoint.

Contrast enhancement attenuation units were calculated from 13 tissues and organs of 20 rats at five different times after bolus 125I-diatrizoate administration. Percent distribution volume of diatrizoate was calculated from these results. The statistical significance of differences in contrast enhancement between each of 72 tissue pairs was determined at each of the five times. A similar treatment of percent distribution volume for 60 tissue pairs was determined. The time elapsed after contrast medium injection appears to be of pivotal importance in contrast enhancement diagnosis. Calculation of percent contrast distribution volume is of potential diagnostic importance, since it reveals contrast medium behavior not evident from a visual perusal of scans. The above methods can be readily adapted to computed tomography scanning.