Imaging of common problems in pediatric urology.

Many imaging modalities are available to study children with urologic disorders. Ultrasonography, renal scintigraphy, and voiding cystourethrography are best for study of patients with infection and antenatal hydronephrosis; intravenous urography, for hematuria and wetting; ultrasonography and CT, for tumor; and CT, for trauma.

Flat chest in chronic bronchopulmonary dysplasia.

In patients with chronic bronchopulmonary dysplasia, the anteroposterior dimension of the chest on the lateral radiograph is often relatively narrow compared with the chest width on the frontal radiograph. A prospective comparison was made of pediatric clinic outpatients who had chest radiography during a 1-month period. Chest widths and thicknesses were measured from the anteroposterior and lateral radiographs, respectively, and a dimensionless ratio of width to thickness was calculated. The chest thus measured was significantly flatter (p less than 10(-6] in 18 patients with chronic bronchopulmonary dysplasia than it was in 128 unaffected patients and in 18 unaffected age-matched patients; there was, however, considerable overlap in chest dimensions between patients with and without bronchopulmonary dysplasia. We speculate that the abnormality results from a combination of demineralized bones, prolonged recumbent positioning, and chronic sternal retraction. It is plausible, but remains to be proved, that this chest wall deformity may be clinically deleterious because it interferes with respiratory mechanics. This prospective comparison of patients with and without bronchopulmonary dysplasia shows that despite considerable overlap in chest dimensions, patients with bronchopulmonary dysplasia tend to have a distinctive chest deformity whose measured difference from control patients is statistically significant.

Trisomy 21 in newborn infants: chest radiographic diagnosis.

Chest radiographs of 30 infants with trisomy 21 and 881 unaffected infants were evaluated for the following findings common in trisomy 21: multiple manubrial ossification centers, 11 rib pairs, and a bell-shaped chest. Radiographs were obtained in the first 48 hours of life. Of the 881 unaffected infants, 85 (9.6%) exhibited multiple manubrial ossification centers; 46 (5.2%), 11 rib pairs; and 208 (23.6%), bell-shaped chest. Of the 30 infants with trisomy 21, 24 (80%) exhibited multiple manubrial ossification centers; ten (33%), 11 rib pairs; and 24 (80%), bell-shaped chest. The probability of trisomy 21 in routinely radiographed newborn infants is 0.05% when none of the three findings is present, 1.6% with multiple manubrial ossification centers alone, 0.2% with 11 rib pairs alone, and 0.7% with bell-shaped chest alone. The probability of trisomy 21 increases in patients with two findings and reaches 58.4% in patients with all three findings.

Genitourinary malformation with calcified intraluminal meconium and pulmonary hypoplasia.

Calcified intraluminal meconium is a rare finding in newborn infants that is often associated with communication between the urinary and gastrointestinal tracts. Frequently such infants die because of respiratory problems. An illustrative case is presented, and pulmonary hypoplasia is suggested as an etiology of the respiratory difficulties observed.

Three-dimensional ultrasonographic imaging of the neonatal brain in high-risk neonates: preliminary study.

The aim of this investigation was to compare the utility of three-dimensional ultrasonography versus two-dimensional ultrasonography in imaging the neonatal brain. Thirty patients in the neonatal intensive care unit underwent two-dimensional and three-dimensional ultrasonography. The resultant two- and three-dimensional images recorded on film and three-dimensional volumes (reviewed on a workstation) were evaluated independently. Comparable numbers of normal and abnormal studies were diagnosed by each modality. Axial images were considered useful in approximately 50% of three-dimensional cases. Image quality, overall and in the far-field, was rated higher on two-dimensional images. Three-dimensional sonographic acquisition time in the neonatal intensive care unit (1.7 min+/-0.7 standard deviation) was significantly shorter than that for two-dimensional sonography (9.0+/-4.5 min). The total time for evaluation on the three-dimensional workstation (4.4+/-1.1 min) was significantly less than that for two-dimensional images on film (10.6+/-4.7 min). In conclusion, three-dimensional ultrasonography is a promising, diagnostically accurate, and efficient imaging tool for evaluation of the neonatal brain; however, visualization must improve before it can replace two-dimensional ultrasonography.