W D Middleton

PURPOSE: To determine the spectrum of sonographic findings, clinical implications, and pathologic correlation in patients with testicular microlithiasis (TM). MATERIALS AND METHODS: The cases of 42 patients with the characteristic appearance of TM on sonograms were retrospectively evaluated for the number, pattern, and distribution of echogenic foci and for associated intratesticular abnormalities. Medical records and pathologic reports were reviewed. RESULTS: Considerable variation was found in the number and distribution of occurrences of TM (five to 60 echogenic foci per transducer field). In some patients, peripheral clustering was seen. Most patients demonstrated side-to-side symmetry, but asymmetric distribution was seen in eight patients and unilateral foci were seen in one patient. In 17 patients, a germ cell neoplasm was seen. One additional patient had a focal lesion that was proved to be an infarct. CONCLUSION: TM has a characteristic sonographic appearance. Because of the 40% occurrence of primary testicular neoplasm in association with it, TM cannot continue to be considered a benign finding.

Ultrasonography of the rotator cuff and biceps tendon was investigated in 106 patients who had been referred for arthrography of the shoulder. Both the sensitivity and the specificity of ultrasound in detecting a tear of the rotator cuff were 91 per cent. The predictive value of a negative sonogram was 95 per cent and the predictive value of a positive sonogram was 84 per cent. Ultrasonography proved to be superior to arthrography in the examination of the normal and abnormal biceps tendon. Sonographically detectable effusions from the tendon sheath of the biceps were present in 19 per cent of this population of patients. This finding was statistically highly associated (90 per cent) with rotator cuff tears and other soft-tissue abnormalities of the shoulder. Based on these results, it appears that ultrasonography can be used as the initial imaging test for many patients with suspected abnormalities of the rotator cuff or biceps tendon.

Color Doppler ultrasound with point spectral analysis was performed on 30 testes of 15 asymptomatic volunteers. Intratesticular arteries and testicular capsular arteries were imaged in all 30 cases. Waveforms from these vessels were similar and consistently showed a low-impedance pattern with high levels of diastolic flow. This reflects the low vascular resistance of the testis. Supratesticular arteries were also identified in all 30 cases. In addition to the low-impedance-type waveforms from the testicular artery, waveforms obtained in the supratesticular region also originated from the deferential and/or cremasteric arteries. This resulted in some waveforms with high-impedance patterns, reflecting the high vascular resistance of the epididymis and peritesticular tissues. We believe that color Doppler ultrasound is capable of reliably showing the normal testicular arterial anatomy by imaging intraarterial blood flow. Knowledge of the normal color Doppler appearance and waveform characteristics of the testicular artery should aid in diagnosing scrotal conditions that alter blood flow.

Color Doppler ultrasound was used to image the ureteral jets in 17 healthy subjects and 26 patients with ureteral calculi proved with intravenous urography. In patients with ureteral calculi, three patterns of ureteral jets were seen: no detectable urine flow from the symptomatic side (12 patients), low-level continuous flow from the symptomatic side (four patients), and periodic ureteral jets on the symptomatic side that were not significantly different from ureteral jets of healthy subjects (10 patients). Of the 12 patients with high-grade obstruction on urograms, 11 had ureteral jets significantly different from those of healthy subjects (either no detectable ureteral jets or continuous low-level jets on the symptomatic side). Only three of the 11 patients with low-grade obstruction or nonobstructing stones had ureteral jets that were different from those of healthy subjects. It is concluded that analysis of ureteral jets with color Doppler can enable detection and qualitative determination of the degree of ureteral obstruction in many patients with unilateral ureteral calculi.

MR imaging was performed through the carpal tunnel in 18 wrists of nine normal volunteers and compared with cryomicrotome sections from cadaver wrists. MR reliably imaged the flexor retinaculum and carpal bones and thus defined the borders of the carpal tunnel. In all cases the median nerve was seen as an ovoid structure of moderate signal intensity and was easily distinguished from the flexor tendons of the hands running in the carpal tunnel. The tendons were separated from each other by their tendon sheaths, and this allowed for identification of the various tendons. Anatomic variations encountered in the normal volunteers included anomalous positioning of the origin of the lumbrical muscles within the carpal tunnel in two, persistent median arteries in two, and interposition of the median nerve between the flexor pollicis longus and the superficial flexor tendon to the index finger in one. Preliminary observations in 10 wrists of patients with carpal tunnel syndrome include segmental and diffuse swelling of the median nerve in six, distortion of the nerve in one, and thickening of the tendon sheaths in one. We conclude that MR imaging accurately and reliably displays the normal anatomy of the carpal tunnel and can detect morphologic changes in patients with carpal tunnel syndrome.