No abstract

Sonograms and radiographs of the lumbar spine in 51 fetuses and neonates with thanatophoric dwarfism, achondroplasia, and osteogenesis imperfecta type II were retrospectively evaluated. Study data included 27 prenatal and 27 neonatal sonograms and radiographs in 40 fetuses and neonates and 11 cases described in the radiology literature. To precisely compare the sonographic and radiographic appearances of platyspondyly in dysplasia, a simple vertebral ratio was obtained from measurement of vertebral interspace and vertebral body height. Normal ranges were obtained from sonograms in 125 normal fetuses and from radiographs in 55 normal fetuses. The severe platyspondyly of thanatophoric dysplasia and the milder platyspondyly of achondroplasia were detected by about 20 menstrual weeks. The vertebral bodies appeared slightly larger on sonograms than on radiographs in both normal fetuses and fetuses with dysplasia.

The authors report two cases of coexistent pneumomediastinum and diabetic ketoacidosis. One patient had pneumothorax as well. Hyperpnea or vomiting, or a combination of the two, may be the etiologic agent in such cases. The prognosis is excellent and there is prompt regression of the pneumomediastinum following correction of the ketoacidosis.

Inflammatory effusions and diffuse neoplasia in the fatty retroperitoneal space, which can alter the perirenal fat, can be recognized radiographically because of density differences. The opacity of fluid and tumor accentuates the remaining fat which conforms to the renal contour. This perirenal fatty border appears as a lucent strip when the perirenal fat is not violated and as abnormal perirenal streakiness when the perirenal fat is infiltrated by fluid or tumor. Six cases are described.

Ultrasound followed by aortography, if necessary, has been a useful approach in the diagnosis of suspected renal agenesis.