Quantitative analysis of ultrasonogram of the prostate.

In 51 cases with prostatic cancer, 88 with prostatic hypertrophy, 109 with prostatitis, and 174 normal subjects, the following five parameters were calculated from prostatic ultrasonograms scanned transrectally; prostatic weight (W), presumed circle area ratio (PCAR), anteroposterior diameter/transverse diameter (ATR), asymmetry index (ASI), and dissimilarity index (DSI). The W and PCAR were higher in cancer and hypertrophy than in prostatitis and normal subjects. The ATR and ASI were higher in cancer. The DSI was lower in hypertrophy. A canonical discriminant analysis using these five parameters disclosed two canonical variates that were useful to separate the disease entities: one separated cancer and hypertrophy from prostatitis and normal subjects, and the other separated cancer from hypertrophy. The coefficients of these variates indicated that cancer was separated from prostatitis and normal subjects by increases in W and ATR and from hypertrophy by the greater effect of increases in ATR (as compared to PCAR) and the small increases in W.