Magnetic deflection forces from atrial septal defect and patent ductus arteriosus-occluding devices, stents, and coils used in pediatric-aged patients.

Magnetic deflection forces and imaging artifact were assessed for 13 pediatric interventional cardiology devices. The magnetic deflection forces incurred by these devices are small compared with physiologic forces experienced in the cardiovascular system.

Efficacy of recombinant human deoxyribonuclease I in the hospital management of respiratory syncytial virus bronchiolitis.

OBJECTIVE: To evaluate the effect of recombinant human deoxyribonuclease I (rhDNase) in shortening the length of the hospitalization and improving the chest radiographs (CXRs) in hospitalized infants with respiratory syncytial virus (RSV) infection as a result of its mucolytic properties. METHODS: Randomized, double-blind, placebo-controlled investigation of 75 patients with RSV bronchiolitis. The study was conducted at the University of Michigan Medical Center and St. Joseph Mercy Hospital, both in Ann Arbor, MI. RESULTS: The respiratory rate, wheezing, and retraction difference scores, obtained by subtracting the hospital discharge score from the corresponding hospital admission score, show no difference between the two groups, but the CXR difference scores show that the rhDNase group improved by 0.46 while the placebo group worsened by 0.60 (p < 0.001). Analysis of covariance for the hospital discharge CXR score after adjusting for the hospital admission score for both groups was done. There was a difference in scores between the two groups, with adjusted mean for the study group of 2.03, and 2.76 for the placebo group (p < 0.001). Paired t test statistics in each of the two groups were computed. For the placebo group, the mean increase of 0.60 was significant (p = 0.02), and the mean decrease of 0.46 for the rhDNase group was also significant (p = 0.02). A one-way analysis of covariance with the hospital discharge CXR scores as the dependent variable and the hospital admission score as the covariate showed that there was a significant difference between the groups (p = 0.01). CONCLUSION: In patients with RSV bronchiolitis, there was significant improvement in the CXRs with the use of rhDNase compared to significant worsening in the placebo group. To our knowledge, this is the first report of the use of rhDNase to treat RSV bronchiolitis.

Pediatric renal neoplasms.

The clinical presentation and radiologic features of neoplastic lesions of the pediatric kidney are presented. Emphasis is placed on Wilms' tumor because it is overwhelmingly the most common pediatric renal neoplasm. Other malignant and benign neoplasms are discussed. Nonneoplastic differential diagnoses are briefly considered.

Use of computerized tomography and chest x-rays in evaluating efficacy of aerosolized recombinant human DNase in cystic fibrosis patients younger than age 5 years: a preliminary study.

The aim of this study was to evaluate the ability of high-resolution computerized tomography (HRCT) of the chest and chest x-rays (CXR) to determine efficacy of inhaled recombinant human DNase (rhDNase) in cystic fibrosis (CF) patients younger than 5 years of age. A randomized, double-blind, placebo-controlled pilot study of 12 patients with CF younger than 5 years of age, attending the University of Michigan Cystic Fibrosis Center (Ann Arbor, MI) was conducted. The changes in the HRCT and CXR score from baseline to day 100 of therapy were assessed using a previously validated scoring system. The mean changes of HRCT scores between the rhDNase and placebo groups were found to be significant at the 95% level, with mean change +/- SE mean of - 1.00 +/- 0.53 and 0.58 +/- 0.24 for rhDNase and placebo groups, respectively (P = 0.02). The difference in CXR score was not significant between the two groups. An analysis was performed to relate HRCT subscores to CXR score; only thickening of the intra-interlobular septae was significantly correlated with the total CXR score (r = - 0.7, P < 0.01). There was improvement in the parents' assessments of the patients' well-being, with improvement in physical activity, decreased cough, sleep quality, and appetite in those subjects receiving rhDNase. We conclude that the administration of rhDNase was associated with improvement in the HRCT scan in CF patients younger than 5 years of age. Findings indicate that HRCT of the chest is useful and sensitive in studying responses to therapy in patients with CF lung disease. To our knowledge, this is the first report of the use of HRCT to assess the effectiveness of a therapeutic modality in so young a CF patient population.

Cervical spine standards for flexion radiograph interspinous distance ratios in children.

RATIONALE AND OBJECTIVES: The purpose of this study was to quantitate the interspinous distances in a group of children as they underwent flexion during lateral radiography. MATERIALS AND METHODS: The cases of 59 children with minor trauma who underwent lateral flexion radiography were studied retrospectively. Measurements of each cervical interspinous distance and anteroposterior diameter of the adjacent body were used to calculate a ratio of interspinous distance to vertebral body diameter at each level. Linear regression analyses of each ratio to patient age were performed, and means and standard deviations of the ratios at each level were calculated. RESULTS: The ratios did not correlate in a statistically significant manner at any level with age. Therefore, data from all 59 children were used to calculate the mean and standard deviation at each cervical level. Most children with severe ligamentous injury who were considered for fusion had interspinous ratios greater than 2 standard deviations above the mean for the control group. CONCLUSION: Standards for interspinous distances during flexion by children are presented. These standards may prove to be helpful in the evaluation of children for cervical ligamentous injury.

Facet coverage in children on flexion lateral cervical radiographs.

STUDY DESIGN: This radiographic study was designed to attempt to develop standards of facet coverage (overlap) on lateral cervical radiographs during voluntary flexion. OBJECTIVE: To produce normative standards for minimum facet coverage in children. SUMMARY OF BACKGROUND DATA: Previous studies on normative standards of facet coverage have been performed only in adults. METHODS: Thirty-six children with minor trauma had lateral flexion-extension radiographs. A standard filming sequence was used in all. Facet joint overlap at each level was divided by the anteroposterior diameter of the upper adjacent cervical body at each level. RESULTS: On linear regression analysis, these ratios did not vary significantly with age at C2-C3 through C6-C7. Means and standard deviations were determined for C2-C7. CONCLUSIONS: These ratios may prove useful in evaluation of children with possible ligamentous injury.

Imaging and the child with abdominal pain.

Abdominal pain is a common presenting symptom in children. A substantial percent of unscheduled paediatric office visits and paediatric emergency room visits are due to abdominal pain. Children may present with an acute episode of pain or with chronic, recurrent pain. Only a small fraction of children presenting with abdominal pain will prove to have an organic cause necessitating interventional management. In this essay, a discussion of abdominal pain is presented, with particular emphasis on the role of radiologic imaging tests to investigate potential causes of abdominal pain. The more common and clinically significant causes of abdominal pain in a child will be discussed in greater detail.

Clinics in diagnostic imaging (74). Midgut malrotation with volvulus.

Midgut malrotation with volvulus is a life-threatening surgical emergency. Prompt diagnosis and treatment is paramount to good outcome. Imaging plays a key role in confirming the diagnosis. A two-day-old male infant presented with bilious vomiting and was diagnosed by upper GI examination to have midgut malrotation and volvulus. The gut was ischaemic but viable at surgery. Radiological features of malrotation and volvulus are presented and discussed.

Clinics in diagnostic imaging (80). Ileocolic intussusception.

Intussusception is a common but life threatening gastrointestinal emergency that occurs in the infant or young child. A three-year-old boy presenting with abdominal pain and vomiting was diagnosed to have the target sign on ultrasonography. An ileocolic intussusception was initially reduced using air enema. Recurrent intussusception 12 hours later was reduced by barium enema. In the proper hands, ultrasonography has a high diagnostic accuracy rate for intussusception. For treatment, air enema is usually perferred to barium enema. Air enema is a safe, rapid, and clean procedure that has been shown to achieve a high reduction rate, comparable to that of barium enema. Ultrasonographically-guided hydrostatic reduction of intussusception has also been recently described and is an effective alternative.

MR of physeal fractures of the adolescent knee.

The aim of this study was to assess physeal fractures of the pediatric knee identified by MR imaging and to describe the MR findings of such fractures. The authors reviewed 315 consecutive pediatric knee MR examinations done to assess for traumatic injury. The MR images were reviewed for evidence of physeal fracture. Fractures were classified by the Salter-Harris system, and associated findings and injuries were noted. Plain radiographs and medical records were reviewed. Seven distal femoral physeal fractures (Salter II, n = 6; Salter III, n = 1) and two proximal tibia physeal fractures (Salter III, n = 1; complex Salter IV, n = 1) were identified. Magnetic resonance demonstrated widening of a portion of the physis with visualization of a metaphyseal/epiphyseal fracture line. Periosteal elevation was observed in six cases. Four patients had associated ligamentous or meniscal injuries. Plain radiographs were available for review in eight patients. Bone abnormalities suggesting fracture were evident in six of eight patients; however, the fracture was fully delineated in only one patient. The diagnosis or confirmation of fracture by MR changed clinical management in seven of eight patients in whom follow-up was available. Physeal fractures of the pediatric knee are occasionally diagnosed by MR. Magnetic resonance provides improved delineation of non-displaced physeal fractures of the knee, while simultaneously allowing for evaluation of soft tissue structures.

Fractures of the first rib in child abuse.

PURPOSE: To evaluate the incidence and specificity of fracture of the first rib as an indicator of child abuse and to determine a mechanism of fracture. MATERIALS AND METHODS: All infants and young children with rib fractures who were seen at the radiology department of an academic medical center over a 2-year period were identified from the radiology data base. RESULTS: Rib fractures were attributed to child abuse in 12 of 35 children identified. Apart from a neonate with congenital osteogenesis imperfecta, only three children, all abused, had first-rib fracture, one bilaterally. Two additional children with first-rib fracture were identified from years prior to the study period. In four children, first-rib fractures were "isolated," without fractures of adjacent bones. CONCLUSION: Child abuse should be considered in cases of pediatric rib fracture, particularly fracture of the first rib. Possible mechanisms for first-rib fracture include impact force, compressive force, and shaking or acute axial load (slamming), which cause an indirect fracture.

Sonography of the shoulder: evaluation of the subacromial-subdeltoid bursa.

The purpose of this essay is to illustrate the sonographic findings in patients with abnormalities of the subacromial-subdeltoid bursa. The anatomy of the subacromial-subdeltoid bursa is complex. This paper illustrates the complexity of the normal bursa and the findings in shoulders with bursal distension.

Fatal lymphoproliferative disease as a complication of Evans syndrome.

A 9-month-old boy had bruising and petechiae. Investigation revealed a Coombs-positive hemolytic anemia and immune-mediated thrombocytopenia. The infant was treated with intravenous immunoglobulin and steroids. The infant eventually had recurrent fevers, hepatosplenomegaly, pulmonary nodules, and parenchymal central nervous system (CNS) lesions develop. Results of a lung biopsy revealed a polyclonal lymphoproliferative disease. Polymerase chain reaction analysis showed the presence of the Epstein-Barr (EB) viral genome in the lung nodules. The infant died from progressive lung disease 6 months after the initial symptoms of Evans syndrome. Lymphoproliferative disease is known to occur in a variety of settings after immunosuppression, especially in solid organ transplant recipients. We report a case of polyclonal lymphocyte proliferation in a patient with Evans syndrome.

Pitfall: anomalous umbilical vein and absent ductus venosus in association with right congenital diaphragmatic hernia.

Congenital abnormalities of the umbilical venous system are rare. A case of fatal right congenital diaphragmatic hernia (CDH) in association with an anomalous umbilical vein bypassing the liver and directly entering the right atrium is presented. The ductus venosus was absent. Although much of the liver was within the right hemithorax, radiographs showed an apparently normal umbilical venous catheter (UVC) course, suggesting a normally positioned liver and mitigating against the diagnosis of CDH. Aberrant umbilical drainage, yielding a falsely normal appearing UVC course, may delay the diagnosis of CDH.

MR imaging differentiation of soft-tissue hemangiomas from malignant soft-tissue masses.

OBJECTIVE: The purpose of this study was to determine whether MR imaging features can reliably distinguish hemangiomas from malignant soft-tissue masses. MATERIALS AND METHODS: We retrospectively reviewed MR imaging studies of 22 patients with soft-tissue hemangiomas and 22 patients with malignant soft-tissue masses. Images were reviewed and agreement reached by a consensus interpretation of two observers and by an independent observer. Masses were evaluated for signal intensity on T1- and T2-weighted images, for enhancement with gadolinium administration, and for morphology (lobulation, septation, central low-intensity dots). Lesion T2 signal and lesion enhancement with gadolinium administration were also objectively measured using regions of interest and comparison with skeletal muscle. RESULTS: Signal intensity on T1-weighted imaging of hemangiomas and malignant soft-tissue masses was similar. Subjective analysis showed greater T2 signal and gadolinium enhancement in hemangiomas; however, the differences were not statistically significant on objective analysis. Lobulation, septation, and central low-signal-intensity dots were all more common in hemangiomas, with statistical significance achieved; the combination of all three findings was specific for hemangioma. CONCLUSION: Although no single MR imaging feature was diagnostic in this study, analysis of lesion morphology, signal intensity, and enhancement with gadolinium allowed MR imaging differentiation of hemangiomas from malignant soft-tissue masses.

Ileocolic intussusception presenting with bilious vomiting due to extrinsic duodenal obstruction.

We present a case of a child presenting with bilious vomiting due to extrinsic duodenal obstruction by an ileocolic intussusception. The clinical presentation, radiographic findings, and use of sonography are discussed.