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SUMMARY Both diagnostic ultrasound and magnetic resonance imaging (MRI) are used for investigation of the presence and severity of rotator cuff lesions. There is no consensus as to which is the more accurate and cost-effective study. We sought to examine the sensitivity of ultrasound, when used by one experienced radiologist with modern equipment. We compared the ultrasound and surgical results obtained from 68 patients. Ultrasound showed a sensitivity of 89% and specificity of 100% (Positive Predictive Value 100%) for full-thickness tears, and a sensitivity of 79% and specificity of 94% (Positive Predictive Value 87%) for partial-thickness tears. We found that shoulder ultrasound, in the hands of an experienced radiologist with the use of modern high-resolution equipment, is highly sensitive in differentiating complete tears and partial-thickness tears. Our results are similar to the best published results for MRI and given that ultrasound is significantly cheaper and more available, ultrasound by an experienced radiologist should be considered as a primary diagnostic tool for imaging the rotator cuff.

Seven cases of urachal anomalies are presented. The spectrum of the disorder and the criteria for ultrasound diagnosis are described. Six of seven cases were correctly diagnosed pre-operatively with diagnostic ultrasound, but one case with no cystic component was missed. The appearance of a fixed, midline, cystic, extraperitoneal swelling between the umbilicus and the bladder should suggest the diagnosis.

Reports of biological effects following insona tion with B-mode equipment are compared anc put into perspective with respect to the dosage employed in diagnostic ultrasound examinations Cellular changes have been observed in vitro following irradiation with diagnostic intensities but where the duration of insonation of a fixed tissue target was extended. A small increase in the frequency of sister chromatid exchanges was reported after insonation for 7.5 minutes with a stationary real time transducer. In B-mode imaging the transducer scans the examined tissue and an equivalent single point exposure would be achieved by repeating 560 simple scans of the same plane. In similar studies by the authors this bioeffect occurred only at greatly increased total energy exposure, resulting from an increase in both the energy content within each pulse and the duration of insonation of a fixed target. Further research is required to determine whether the dosage relationship is linear producing the same effect if a constant total amount of energy is distributed in a varying time relationship.

Ultrasonic visualisation procedures provide the clinician with additional diagnostic information to allow a high level of patient care, which is particularly valuable in pregnancy management. The benefit will invariably exceed any risk from the examination in symptomatic patients. The safety of diagnostic ultrasound in pregnancy is assumed from negative findings in epidemiological studies, and on the absence of any report of adverse effects in children following in utero in-sonation. Reports of subtle biological responses to ultrasound relate to in vitro insonation of cells under specially selected conditions. Neither the importance of cellular bioeffects nor their possible extrapolation to the human in vivo situation is clearly understood. Overseas Government bodies and Ultrasound Societies, and the Australian Society for Ultrasound in Medicine agree that there is no independently verified evidence of harmful effects of diagnostic ultrasound, and advocate its use wherever a medical reason exists.