The significance of MRI abnormalities in children with neurofibromatosis.

We prospectively evaluated 47 children with neurofibromatosis to determine whether the previously reported high signals on magnetic resonance imaging (MRI) (prolonged T2) correlated with CT, brainstem auditory evoked responses (BAER), EEG, clinical examinations, cognitive abilities, or seizure disorder. Thirty percent of children had a history of seizures and 70% had either learning disabilities or mental retardation. Overall, 74% had an abnormal MRI examination. Sixty-two percent had high signals (prolonged T2) on T2-weighted images. Abnormal signals were located primarily in the basal ganglia, brainstem, and cerebellum. Twenty-five percent of patients had abnormal EEGs, 28% had abnormal CTs, and 27% had abnormal BAER examinations. The abnormal signals on MRI did not consistently relate to findings on CT, BAER, EEG, school placement, or clinical examination. The abnormal signals presumably reflect areas of abnormal brain parenchyma, either hamartomas, heterotopias, or local areas of brain dysplasia.

Familial total ophthalmoplegia with iris transillumination (a neurocristopathy).

A family with total (internal and external) ophthalmoplegia had associated iris transillumination. No abnormal visual-evoked response brain lateralization indicative of albinism was found. On the basis of avian chimera experiments showing iris muscles to be derived from neural crest cells, we proposed a neurocristopathic theory to explain all clinical findings in this family.

Diabetic ketoacidosis. Neurologic collapse during treatment followed by severe developmental morbidity.

Diabetic Ketoacidosis (DKA) remains the leading cause of death in children with type 1 diabetes mellitus. Complications occurring during DKA treatment include cerebral edema and neurologic collapse. Developmental outcomes following neurologic deterioration during DKA have varied from no sequelae to severe developmental disabilities. A total of three children developed neurologic deterioration during treatment of DKA at Buffalo Children's Hospital between 1984 and 1987. The authors treated aggressively for cerebral edema. Characteristic findings on the computed tomography (CT) scans and magnetic resonance imaging (MRI) of the brain included hemorrhagic infarctions of the thalami, basal ganglia and lentiform nuclei. The authors conducted developmental follow-up examinations between 1-1/2 - 3 years following recovery from DKA coma. Although they noted significant recoveries over time, developmental disabilities persisted. The clinical courses and neuroradiographic findings of these patients are compatible with sequelae of central brain stem herniation and cytotoxic brain injury. Continued efforts are needed in the prevention and early detection of clinically significant cerebral edema during treatment of DKA.

Imaging of a pediatric abdominal mass.

The approach to the child with an abdominal mass will be aided by careful consideration of the radiographic imaging modalities available at an institution. The relative advantages, disadvantages, costs, and radiation of each modality are presented. The recommended workup of a pediatric abdominal mass, as well as the most common masses and their differential diagnosis, are outlined.

Allograft epiphysiodesis for slipped capital femoral epiphysis.

During this retrospective investigation, use of freeze-dried irradiated allograft for achieving epiphysiodesis in patients with Grade I or Grade II slipped capital femoral epiphyses was evaluated. The study reviewed 40 grafting procedures in 33 patients: 20 patients were boys and 13 were girls, whose average age was 13 years old. The group included 31 Grade I slips and 9 Grade II slips. Six were unstable and 34 were stable. Procedure time averaged 1 hour 57 minutes and blood loss averaged 360 ml. The average time to complete physeal closure was 28 weeks. An incomplete bony physeal bridge, apparent at an average 11 weeks, may impart earlier stability. Thirty-eight cases had followup averaging 3 years 6 months. At most recent evaluation, according to the Harris hip rating system, 35 hips had excellent ratings, 1 had a good rating, and 2 had fair ratings. Six patients were identified with major postoperative complications, including 1 case each of segmental avascular necrosis, chondrolysis, femoral neck fracture, subtrochanteric hip fracture, bilateral progressive coxa vara deformities requiring corrective osteotomies, and a unilateral progressive coxa vara deformity. The senior author (TLS) currently uses a fluoroscopically guided percutaneous lateral approach, a cannulated reaming system, and freeze-dried irradiated cortical allograft. The procedure promotes premature physeal closure. Allograft epiphysiodesis is an alternative operating technique for treating patients with a slipped capital femoral epiphysis.

Hypercalcemia and pancreatitis in a child with adynamic bone disease.

We report a 12-year-old boy receiving long-term peritoneal dialysis who developed marked hypercalcemia and pancreatitis. Hypercalcemia was successfully treated by conducting dialysis with non-calcium-containing dialysate fluid. Factors predisposing to the development of hypercalcemia included the presence of adynamic bone disease and the use of vitamin D and calcium carbonate therapy. This case is presented to emphasize potential complications that can be associated with the adynamic bone lesion in patients on peritoneal dialysis.

Normal pituitary stalk size in children: CT study.

A retrospective study was undertaken of 1005 normal contrast-enhanced head computed tomographic (CT) scans in children to determine normal standards for pituitary stalk diameter, basilar artery diameter, and their ratio for age and gender. The pituitary stalk enlarges with age, and girls have larger stalks than do boys after age 8. The pituitary stalk-to-basilar artery ratio is easily estimated visually. Ratios greater than or equal to 1 are unusual in normal children. A ratio greater than or equal to 1 should prompt direct measurement of the stalk and comparison with age-matched normal values. If the stalk measurement is greater than 2 SD above the age-matched mean, it is presumably abnormal and deserves further evaluation for numerous possible pathologic conditions including histiocytosis X, pituitary adenoma, hypothalamic lesions, Rathke cleft cysts, metastases, sarcoidosis, hypothyroidism, and infection.

Metastatic Wilms' tumor to the liver with MR findings simulating cysts: case report emphasizing need for integrated imaging.

A case of Wilms' tumor metastatic to the liver with previously undescribed MR findings is presented. Although there is no evidence that there were hepatic metastases at presentation in this case, small lesions with this appearance would be difficult to detect with MRI. This could lead to incorrect staging of Wilms' tumor examined by MRI alone.

CT evaluation of blunt abdominal trauma in children: comparison of ultrafast and conventional CT.

Previous reports describing the use of ultrafast CT have emphasized its value in evaluating the heart, chest, and airway. We describe our experience using this technology on children with blunt abdominal trauma. We retrospectively reviewed 54 consecutive ultrafast CT studies and 30 consecutive conventional dynamic CT studies performed on children after blunt abdominal trauma. Thirty percent of the scans showed abnormalities. CT or pathologic follow-up was available for all abnormal cases. We compared scans made with these two techniques for diagnostic accuracy, amount of visible motion on each slice, and contrast enhancement seen on each study. A protocol of 0.4-sec images and 2 ml/kg IV contrast material administered before scanning was used for the ultrafast CT scans. A standard protocol of 2-sec scanning and 3 ml/kg IV contrast material was used for conventional CT studies. There was no difference in diagnostic accuracy between the two techniques. There was significantly less visible motion (p less than .0001) and significantly better contrast enhancement (p less than .0001) seen on the ultrafast CT studies. Two of 54 ultrafast scans had images with sufficient motion to require repeated scanning, compared with 13 of 30 conventional CT studies. In addition, ultrafast scans required less sedation, decreased radiation dose, and improved accessibility of the patient to support personnel. Ultrafast CT is a valuable technique for abdominal imaging, offering equal diagnostic accuracy with improved image quality and important benefits to the patient.

Airway evaluation in children with use of ultrafast CT: pitfalls and recommendations.

Ultrafast computed tomographic (CT) evaluation of the airway can be performed with either 50-msec low-resolution images (cine CT) or 100-msec high-resolution images (high-resolution CT). To determine the best imaging strategy for ultrafast CT of the pediatric airway, the authors prospectively compared ultrafast CT and endoscopy in 20 children. Both studies were performed in 11 patients; cine CT alone was performed in six and high-resolution CT alone in three. Six patients had normal anatomy. Six patients had focal tracheal stenoses, four had tracheomalacia or laryngomalacia, one had a laryngoesophageal cleft, one had irregularity and narrowing in the subglottic area, one had laryngeal papillomas, and one had focal stenosis with stoma granuloma. Cine CT results agreed with those of endoscopy in 10 of 17 cases. In five cases focal stenosis was misinterpreted with cine CT as tracheomalacia. High-resolution CT results agreed with those of endoscopy in 10 of 14 cases. The results of a technique that combined high-resolution CT for the entire airway and cine CT at selected areas agreed with those of endoscopy in 10 of 11 cases; only a tracheoesophageal cleft was missed with the combined technique. For the greatest diagnostic accuracy with ultrafast CT in evaluation of the pediatric airway, both cine and high-resolution modes should be used.

Renal malposition in patients with omphalocele.

We describe a boy with a history of omphalocele who presented with gross hematuria. Subsequent evaluation revealed a cephalad right kidney malposition and the hematuria was of lower tract origin. To investigate the frequency of this radiographic finding the medical records of 15 patients with omphalocele who presented between 1979 and 1985 were reviewed. Studies of the urinary tract were performed after omphalocele closure. Of 7 cases (46 per cent) with abnormal cephalad renal displacement the kidney was on the right side only in 3 and it was bilateral in 4. The omphalocele contents consisted of gastrointestinal tract only in 9 patients, and liver and gastrointestinal tract in 6. All 6 patients with omphaloceles that included the liver had cephalad renal displacement. One patient with small bowel alone in the omphalocele had right kidney displacement. Clinicians should be aware of this variation to avoid confusion and further unnecessary evaluation.

Diagnosis and management of the hydronephrotic type of multicystic dysplastic kidney. Use of antegrade pyelography.

The distinction between the hydronephrotic type of multicystic kidney disease and ureteropelvic junction obstruction can be difficult using conventional imaging techniques. Antegrade pyelography with or without percutaneous nephrostomy may be performed to confirm the diagnosis of complete ureteral obstruction and to guide management decisions. One may elect either immediate nephrectomy or observation after performance of this diagnostic procedure. Reconstruction of nonsalvageable kidneys is avoided.

Intrathecal administration of iopamidol in children: clinical and diagnostic results.

An open label, noncomparative clinical trial of intrathecal iopamidol in children was performed. Sixty-one subjects between the ages of 24 days and 17 years were studied. Opacification of the subarachnoid space was adequate in all cases. Mild adverse reactions were detected in 10% of the participants. Seizures, EEG alterations or other severe reactions did not occur. The findings confirm the efficacy and safety of iopamidol as an intrathecal contrast medium in pediatrics.

John Caffey Award paper. Avascular necrosis: early MR imaging and histologic findings in a canine model.

To examine the early MR and histologic changes of avascular necrosis, we surgically devascularized the distal femur of adult beagle dogs and performed short TR/short TE MR imaging and histologic examinations. MR showed increasing areas of low signal, and histologic examination showed changes of fat necrosis, inflammatory infiltrate, and fibrocytic and bony repair. These processes were divided into four stages. Stage 1 is seen in the first days after surgery and consists of homogeneous high signal on MR and only subtle histologic changes of early fat necrosis. Stage 2, seen by 7 days after surgery, shows linear low-signal areas within the high-signal marrow on MR and fat necrosis and an inflammatory infiltrate on histologic sections. Stage 3, seen by 16 days after surgery, shows patchy low signal occupying more of the marrow on MR with a fibrocytic infiltrate on histologic sections. Stage 4, seen by 23 days after surgery, shows a more homogeneous low and intermediate signal on MR and histologic findings of more organized fibrocytes and the onset of new bone formation. Using this model, we have proved that MR imaging can show marrow changes as soon as 1 week after the onset of avascular necrosis. Whereas MR imaging showed a progression of increasing areas of low signal, the histologic findings seen during this time were diverse, including inflammatory infiltration (a previously unreported finding), fat necrosis, and fibrocytic and osseous repair.

Glomerulocystic kidney disease: case report.

A newborn infant with abdominal masses was found to have Glomerulocystic Kidney Disease. Imaging showed markedly enlarged kidneys with multiple macroscopic cysts. Radiographic and clinical findings are discussed.

Neonatal nasopharyngeal hairy polyp: CT and MR appearance.

We report a rare tumor of the nasopharynx in the neonate: the teratoid or hairy polyp. In addition to the traditional modes of evaluation (barium swallow, plain radiography, and indirect laryngoscopy), CT and magnetic resonance were used to assess this unusual cause of respiratory distress and vomiting in a newborn.