Efraim Avni

US demonstration of pyelitis and ureteritis in children.

The authors report a new ultrasonic sign of urinary tract infection in children: thickening of the renal pelvis and/or ureteral wall. This thickening as encountered in 10 children, (10 months to 12 years) all with urinary tract infection, appears to result from inflammatory changes and to correspond to a sonographic sign of pyelitis and ureteritis. These alterations of the walls are similar to striations and folds described in this pathology on intravenous pyelograms. The thickening was the only sign of abnormality of the urinary tract in two cases; it was observed without reflux in four cases. The demonstration of this pattern should lead to further uroradiological investigations and to appropriate treatment.

Hyaline membrane disease in the newborn: diagnosis by ultrasound.

The authors report a new method of diagnosing hyaline membrane disease (HMD) in newborns: ultrasound. Babies with HMD display a specific pattern with retrohepatic hyperechogenicity on abdominal ultrasound. The specificity of the pattern was verified in 40 prematures with respiratory distress syndrome. The sign was present in 24, and in 22 of these the final diagnosis was moderate or marked HMD. In the last 2, mild HMD was suggested. The pattern was absent in the 16 others, none of whom had HMD. The pattern probably results from an ultrasound artifact: summation of multiple aerated airways surrounded by collapsed alveoli. Follow-up examinations were possible in 13 babies with HMD. Hyperechogenicity disappeared in 8 of these patients within 6–9 days and in 3 within 10–20 days; it persisted for 60 and 70 days in 2 with bronchopulmonary dysplasia. In conclusion, retrohepatic hyperechogenicity in newborns is pathognomonic for HMD and allows an instant diagnosis. The persistence of the pattern could be a useful criterion for evaluation of the prognosis.

Hepatic cysts and hyperechogenicities: Perinatal assessment and unifying theory on their origin

The authors report their experience with the perinatal diagnosis of six cases of hepatic cyst and six of liver hyperchogenicities. The in utero diagnosis of hepatic cysts was difficult when the cysts were large or subhepatic. A precise diagnosis was sometimes achieved only after surgery. Small intraparenchymal cysts tended to regress spontaneously. Liver hyperechogenicities were diffuse or localized. They were unrelated to liver infection, tumors, meconium peritonitis or biliary tract anomaly. Both entities could be related to vascular disruption phenomenon (VDP) in which structural anomalies result from damage to normal development of embryonic or fetal vessels with anomalies of perfusion to the developing organs. The consequences of VDP to the liver are variable depending on the time and duration of the phenomenon. Localized infarct or ischemia can fibrose or calcify leading to segmental hyperechogenicities. Necrosis with tissue reabsorption can be the origin of some (sub)hepatic cysts. When such anomalies are detected there should be a careful study of the placentation, and a search for potential associated anomalies should be undertaken.

A hypothesis for the higher incidence of vesico-ureteral reflux and primary megaureters in male babies

The authors propose a new explanation for the male preponderance in cases with prenatally diagnosed vesico-ureteral reflux and primary megaureters. The theory is based on conclusions drawn from the characteristics of 4 patients (3 perinatal cases and 1 occurring in a 14-year-old boy) presenting with unusual anomalies of the lower urinary tract. In this hypothesis, the male preponderance could be related to an abnormal dilatation of the posterior urethra occurring during the embryological development of the male urethra. The dilatation leads to a flap valve mechanism and to a functional obstruction of the bladder outlet and finally to secondary dilatation of the upper urinary tract. This obstruction may be transitory; reflux and megaureters found in utero or after birth could be considered as sequellae of this phenomenon.

Perinatal renal vein thrombosis. Sonographic demonstration.

The use of ultrasound (US) in the diagnosis of renal vein thrombosis (RVT) remains ill defined because the classical features lack specificity. The authors report three cases of renal vein thrombosis with a common US pattern: hyperechoic streaks in the interlobulary spaces confirming previous reports with the same pattern. The pattern has been observed in neonates as well as in utero. Associated vena cava thrombosis was present in two cases. This sign might be a specific sign of RVT.

Atypical and equivocal sonographic features of the spinal cord in neonates

Thanks to the wider use of sonography to examine the spinal content in the neonate, normal anatomy and anomalies may be detected easily. Yet, unusual sonographic patterns are also observed. These must be differentiated from true pathologies. During a prospective study of 103 neurologically asymptomatic neonates, atypical sonographic patterns were found in 16 patients, corresponding to normal variants in 13. Nine of these 13 patients presented with a widening of the distal part of the central echo complex (one had a dilated ventriculus terminalis). Nerve roots of the cauda equina were disposed asymmetrically in three patients; the spinal cord movements were still present. In two of these babies, this distribution was associated with thin arachnoid pseudocysts. One patient presented with transitorily hyperechoic and narrow subdural spaces, probably related to neonatal dehydration. None of the 13 patients showing normal variants required any treatment. The other 3 patients (of 16) presented with equivocal entities of unknown evolution: sonographic tethered cord, fibrolipoma of the filum terminale and epidural varices. Sonography is highly accurate in evaluating the spinal cord content and aids differentiation of normal and normal variants from equivocal or pathological entities.

Renal duplications : the impact of perinatal ultrasound on diagnosis and management

Perinatal urology is a rapidly expanding field in pediatric urology bringing significant changes in the diagnosis and management of congenital uropathies. Renal duplication was detected by antenatal and perinatal ultrasound in 19 cases (22 duplicated systems). In most cases, no precise diagnosis could be established in utero (4 of 13), but this lack of accuracy is of little clinical significance since all newborns with suspected uropathies undergo complete urological investigations in the perinatal period. Voiding cystogram demonstrated reflux in 11 of 22 cases. On postnatal urography a functioning upper pole was demonstrated in 11 of 22 kidneys. There were 12 ureteroceles: in 8 a nonfunctioning upper pole was removed, while 3 were endoscopically incised with good functional improvement and 1 was reimplanted. Early recognition of congenital uropathies in association with duplication by prenatal ultrasound significantly improves patient care allowing early postnatal relief of obstruction by less invasive methods and before infection or persistent obstruction worsens the prognosis.

Pulmonary sequestration-like anomaly presenting as a spontaneously resolving mass

A premature baby boy presented at birth with respiratory distress. A right lower lobe opacity was found on chest X-ray. Pulmonary sequestration was the diagnosis suggested by ultrasound. The size of the mass decreased on subsequent examinations. 4 months later X-rays and sonography failed to demonstrate any remaining mass. This case illustrates another example of involutive pathology and suggests that not all pulmonary sequestration-like anomalies should be operated on.

Prenatal diagnosis of atypical gastroschisis

Perinatal ultrasonography is very important for thedetection, identification, and follow-up of abdominalwall defects. The ability to distinguish between typesof abdominal wall defects and reach a correct diag-nosis is not always easy. We present two unusualcases of gastroschisis with change in the ultrasono-graphic appearance as pregnancy progressed anddiscuss perinatal management.

Antenatal diagnosis of short-limb dwarfism: Sonographic approach

Based on the findings in 12 patients with skeletal dysplasia diagnosed antenatally, the authors propose a tailored approach to the evaluation of foetuses with shortened long bones, depending on the time of discovery, the degree of shortening and the associated findings. During the second trimester, a very short femur [2 standard deviations (SD) −5 mm and less] most probably corresponds to a bone dysplasia, although the differential diagnosis is mainly early intra-uterine growth retardation, and the foetal skeleton should be surveyed completely in order to find supplementary features suggestive of dwarfism. Anomalies of long bones in their shape, thickness or contour, or spinal ossification disorders or under-mineralisation (best evaluated at the level of calvarial bones) are most helpful in determining the type of dysplasia. A short femur (between 2 SD and 2 SD −4 mm) may indicate growth retardation, a chromosomal anomaly or dwarfism. Follow-up examinations are mandatory in order to differentiate between them. During the third trimester a very short femur may indicate a bone dysplasia and the work-up should be the same as in the second trimester. A short femur may correspond to dwarfism of late development, a growth-retarded foetus or constitutional shortness. Various ratios, especially that of the femur/foot, are helpful in differentiating between them. In case of previous family history, a short or very short femur usually indicates recurrence of the dwarfism. In all cases of antenatal diagnosis, confirmation of the sonographic findings should be obtained either by foetal or neonatal radiographs. The approach proposed by the authors should provide sufficient information to counsel the family not only for the ongoing pregnancy but also for subsequent ones.