Ultrasonography of prostatic carcinoma employing amplitude-enveloped (AM) and frequency-demodulated (FM) imaging: in vivo, in vitro, and pathologic correlation

Thirty patients with biopsy proven carcinoma of the prostate were examined with transrectal (TR) (5-MHz linear array transducer) and transabdominal (TA) (3-MHz sector scanner) ultrasonography prior to prostatectomy. All patients had clinical stage A (n = 5) or B (n = 25) disease. Following retropubic radical prostatectomy, in vitro waterbath studies of the resected specimens were performed obtaining both conventional amplitude-enveloped (AM) images and frequency-demodulated (FM) images. The ability of each imaging modality (TR, TA, AM, FM) to detect the cancerous lesion was determined, and in all cases correlation with pathology was obtained. Transabdominal suprapubic ultrasonography did not prove helpful in detecting early carcinoma. Longitudinally oriented linear array transrectal ultrasonography was positive in nearly two thirds of the patients. Insignificantly lower positive correlation with pathologic findings was obtained from in vitro AM images; the lesions were often better visualized on transverse than on longitudinal images. The highest correlation with pathology was obtained from the in vitro frequency-demodulated images.