Histological analysis of ultrasonic images of the prostate: an accurate technique.

Ultrasonography of the prostate furnishes images which still cannot be fully interpreted morphologically. In a cadaver study, the ultrasound images of two groups (21 and 19) prostates, obtained in a water bath, were compared with histology slides taken at corresponding levels. In the first part of the study, using a 4 MHz probe, there was a correlation between hyperechoic lesions and stone formations in 9 out of 15 cases. A relation between hypoechoic lesions and the existence of a carcinoma could also be established in 4 out of 12 cases. In the second part of the study, using a 7 MHz probe, there was a correlation between hyperechoic lesions and stone formations in all cases. Hypoechoic lesions correlated with the presence of a carcinoma in 1 out of 8 cases. The technique used appears to be well suited for the comparative study of ultrasound images and histology. Application of the 7 MHz probe is preferable as, because of a better resolution, smaller lesions can be detected. The results of this study are not very encouraging for the use of transrectal ultrasound for the detection of small prostatic carcinomas.