MRI IN SCROTAL DIAGNOSIS OF SEMINOMA, TER ATOMA AND INFLAMMATION BY MEANS OF A STATISTICAL SCORE

Purpose: To differentiate scrotal pathology via MRI by means of a stat istical score. Methods: Between 1989 and 1995 MR images of 105 patient s with scrotal pathology were rated retrospectively. In 69 cases linea r discriminant analysis was used to differentiate seminoma, teratoma a nd inflammation. Six MRI attributes were found to be necessary and wer e weighted with a factor according to their importance. These factors were used to build a score. Results: Criteria found to be important co ntained the distribution of the variate extensions of elements inside the pathological area and their maximal and minimal signal intensities . Furthermore, the contrast pattern of the pathological area and the v isibility of healthy tissue in the pathological testicle was of import ance. Seminoma was found to be homogeneous and well demarcated against healthy tissue. Teratoma was also well defined but characterised by i nhomogeneous distribution of signal intensities. Inflammation showed d iffuse signal increase of the pathological testicle, especially in T-1 -sequences. Using the score differentiation between tumors and inflamm ation succeeded in 94.2% between seminoma and teratoma in 89.7%. Concl usions: Compared to other studies using visual MR image analysis diffe rentiation of scrotal diseases was improved by using a statistical sto re.