MRI provided complete visualisation of the fetal GI tract, showed specific signal intensities, identified the level of an obstruction, detected a microcolon, and demonstrated communication between urinary and GI tracts. It shows great potential.

We describe the magnetic resonance (MR) patterns of a variety of fetal gastrointestinal (GI) abnormalities. Thirty-two fetuses between 23 and 38 weeks' gestation with abnormal appearance of the GI tract by ultrasound underwent MR imaging with T1- and T2-weighted sequences. The MR aspect of intestinal atresia (duodenal atresia, one case; small bowel atresia, nine cases) included dilatation of the bowel loops, accurate assessment of the normal bowel distal to the atresia (except in the patient with multiple atresia and apple-peel syndrome), and micro-rectum with decreased T1 signal (except in the patient with duodenal atresia). Megacystis-microcolon-intestinal hypoperistalsis syndrome (one case) was indicated by an abnormal signal of the entire bowel and an abnormal pattern for the urinary tract. Meconium pseudocysts (two cases) were easily differentiated from enteric cysts (two cases). High anorectal malformations with (two cases) or without (one case) urinary fistula and cloacal malformation (one case) are described and MR findings are discussed. The capability of MR imaging to demonstrate the normal bowel with intraperitoneal anomalies (e.g., congenital diaphragmatic hernia, and sacrococcygeal teratoma) is emphasized. MR imaging is informative in the diagnosis of GI tract abnormalities, especially the severe malformations, with much more accuracy than sonography.

High resolution ultrasonography based management of acute scrotum is reliable and reproducible. Thanks to its high sensitivity and specificity for the diagnosis of spermatic cord torsion, high resolution ultrasonography can significantly improve the management of acute scrotum in children.

The detection of spermatic cord spiral twist appears a reliable US sign of torsion whatever the testicular consequences.

The finding of a twisted spermatic cord is a highly reliable sign for the diagnosis of testicular torsion. Whereas normal intratesticular perfusion does not dispense with emergency exploratory surgery, direct and complete visualization of a nontwisted spermatic cord strongly indicates that surgery is unnecessary. Strict conditions are required, including time spent on HRUS should not exceed 30 minutes, which generally can only be achieved by a senior pediatric radiologist.

Brain ultrasonography plays a central role in the detection and management of neonatal disease in the preterm infant. Although morphological study, using high-frequency transducers, remains the cornerstone of imaging, pulsed and colour Doppler scans provide additional information and improve the diagnostic and prognostic accuracy of ultrasonography. Particular features of normal brain US in the extremely preterm infant are reported. Cerebral haemorrhage and its different patterns (intraventricular haemorrhage and periventricular hemorrhagic infarction) are described. The value of Doppler techniques is emphasized, e.g. demonstration of coloured signal within the aqueduct of Sylvius, visualization of patency of the terminal veins, demonstration of Doppler spectrum fluctuations, recognition of low blood flow, and the detection of vasodilatation. The sonographic diagnosis of periventricular leucomalacia and its difficulties are documented. Some uncommon brain lesions of the premature infant are illustrated, e.g. gangliothalamic ischaemic damage, cortical necrosis, focal infarcts, etc. The importance of repeating the US examinations until near term is highlighted.

The strategy for morphological investigations in children with acute pyelonephritis (APN) remains debatable. We studied 70 children (median age 2.0 years) admitted with a first episode of pyelonephritis using a high-resolution ultrasound technique (RUS) and compared the results with 99m technetium-dimercaptosuccinic acid (DMSA) renal scintigraphy. The DMSA scan was abnormal in 62 children (89%). However, using a high-frequency transducer we found abnormal sonogram changes in 61 children (87%), consisting of an increased kidney volume in 42, and/or a thickening of the wall of the renal pelvis in 42, and/or a focal hyper- or hypoechogenicity in 36, and/or a diffuse hyperechogenicity in 31 children. Micturating cystourethrography was performed in all children, revealing vesicoureteral reflux (VUR) in 22 (31%). Among those children with VUR, 4 had a normal DMSA scan, 2 an abnormal RUS, and 2 a normal DMSA scan and RUS. Our data suggest that B-mode RUS performed with a high-frequency transducer by a trained radiologist is nearly as sensitive as the DMSA scan in diagnosing renal involvement in children with unobstructed APN and in predicting VUR.

The authors report the use of high frequency ultrasound (7.5-10 MHz probes) for the detection of intestinal complications in 14 children with Henoch-Schönlein purpura. Ultrasound gave information of 3 levels: (1) It explained the acute abdominal pain by showing in all cases the oedematous haemorrhagic infiltration of the intestinal wall, which appeared thickened (3-11 mm): lesions were diffuse (6 cases) or focal (duodenal in 5 cases, jejunal in 2 cases and ileal in one). (2) It followed the evolution of the disease: extension of lesions (5 cases) or resolution (progressive decrease of parietal thickening, reexpansion of small bowel lumen, reappearance of peristalsis). (3) It always detected surgical complication: ileo-ileal intussusception (3 cases), perforation (1 case).