MR characteristics of prostatic carcinoma and benign prostatic hyperplasia at 1.5 T

Sixty-one patients with histologically proven disorders of the prostate [prostatic carcinoma (PC), 41; benign prostatic hyperplasia (BPH), 9; PC and BPH, 11] underwent magnetic resonance imaging at 1.5 T. Using single [spin echo (SE) 400/30] and dual (SE 1,600/30, 90) SE sequences, multislice contiguous scans were obtained in transverse, sagittal, and coronal planes through the prostate. In 27 patients (PC 14, BPH 6, PC and BPH 7) multiecho sequences with eight echoes (SE 1,600/30, 60, 90, 120, 150, 180, 210, 240) were acquired and T2 images were calculated in the planes with best depiction of circumscribed prostatic pathology. In these patients the Bhattacharyya coefficient, a quantitative criterion for the discrimination between normal and pathological tissue, derived by means of mathematical decision theory, was applied. This analysis showed the best discrimination between PC and normal prostate with echo time (TE) 90 and 120 ms [error rate (ER) for confusing these tissues 20-30%]. There was no significant difference between the signal intensities of PC and BPH at any parameter setting, but PC could be discriminated from the compressed peripheral glandular regions that often accompany BPH [minimal ER (20-30%) at TE 90 and 120 ms]. This distinction is of clinical value, since PC usually arises in the periphery of the prostate. Calculated T2 images did not show advantages for the detection of PC.