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The sonographic appearance of echinococcal lesions of the liver was studied in 59 patients. We have proposed a classification of these lesions that reflects the pathology and natural history of the disease: type I, simple fluid-filled cysts; type IR, lesions containing undulated membranes that represent detached endocyst secondary to rupture; type II, lesions that contain daughter cysts and/or a formed echogenic material we call matrix; and type III, dead, densely calcified lesions. The natural progression of hepatic echinococcal cysts is from type I to type III. Daughter cyst formation is part of the natural aging process. When hydatid cysts are infected, they lose their characteristic sonographic appearance and become diffusely hyperechoic.

A retrospective analysis was made of the radiologic features of 30 cases of mycetoma. Conventional radiographs, computerized tomography (CT), and isotope bone scans were assessed. Soft-tissue swelling was the only abnormality in 27%. Periosteal reaction was present in 67%, sclerosis in 53%, endosteal reaction in 50%, and cortical erosions in 43%. Cavities which were found in 33% are important as predictors of the causative micro-organism. Conventional radiographs are essential to the management of mycetoma as bone involvement makes non-surgical cure unlikely. The role of CT in diagnosis and management appears to be minor, except when the thigh is involved. Isotope bone scanning appears to have no value in either diagnosis or management.

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This paper describes a prospective study of the diagnostic radiation doses received in a neonatal intensive care unit (NICU) for a representative radiological technique used at our institution for a number of years and a "low dose" technique similar to that recommended by the Commission of the European Communities (CEC). A 400 speed film-screen combination was used in both techniques. A total of 363 anteroposterior (AP) chest and abdominal films of 77 neonates were accrued. For each radiograph, the entrance skin dose (FSD), energy imparted (EI) and mean whole body dose were determined. For a neonatal AP chest, there was an 18% reduction in the mean ESD per radiograph from 20.0 muGy for the representative technique to 16.4 muGy for the low dose technique (p < 0.0005). The reduction in the mean EI per radiograph values for the two techniques from 7.9 muJ to 7.1 muJ (10%) was statistically significant at the p < 0.017 level, after compensating for the difference in mean field dimensions between the two patient cohorts. The mean whole body dose per radiograph reduction from 4.4 to 3.5 muGy (20%) was statistically significant at the p < 0.0028 level. It was determined that the ESD and EI could be fitted by an exponential function in the equivalent patient diameter, a single parameter indicative of neonate size. Absolute excess childhood cancer mortality risk per film was estimated using risk factors derived for fetal exposures. A "worst case" absolute excess mortality risk per chest radiograph was estimated to be 1.40 x 10(-7) for the conventional technique and was further reduced to 1.11 x 10(-7) for the low dose technique. A blind comparison of patient-matched film pairs for each technique was performed by three radiologists using criteria similar to those specified by the CEC. No statistically significant difference in clinical image quality was found between the two techniques.

Four hundred ninety-two patients, including 449 pregnant patients, 39 nonpregnant control patients, and 4 patients with pelvic masses, had renal ultrasonography using gray scale technique. Measurements of renal pelvic diameters in the normal pregnant patients revealed an overall incidence of 63 percent renal pelvic dilatation over the nonpregnant controls. Maximum normal renal pelvic diameters were 1.1 cm on the right and 0.9 cm on the left. The maximum normal expected renal pelvic diameter (97.5 percent confidence level) in pregnancy is 2.7 cm on the right and 1.8 cm on the left in the last two trimesters of pregnancy. There was no significant difference between primiparous and multiparous patients, but pregnant patients were significantly different from controls in every trimester (p less than 0.01). Maximum dilatation occurred at 24--28 weeks of gestation. The right renal pelvis was enlarged to the greatest degree in 90 percent of normal patients. Patients with pelvic masses showed a similar pattern of right-sided hydronephrosis.

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