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To compare whole-body magnetic resonance (MR) imaging with conventional imaging for detection of distant metastases in pediatric patients with common malignant tumors.This institutional review board-approved, HIPAA-compliant, multicenter prospective cohort study included 188 patients (109 male, 79 female; mean age, 10.2 years; range,1 to 21 years) with newly diagnosed lymphoma, neuroblastoma, or soft-tissue sarcoma. Informed consent was obtained and all patients underwent noncontrast material-enhanced whole-body MR imaging and standard-practice conventional imaging. All images were reviewed centrally by 10 pairs of readers. An independent panel verified the presence or absence of distant metastases. Detection of metastasis with whole-body MR and conventional imaging was quantified by using the area under the receiver operating characteristic curve (AUC). The effects of tumor subtype, patient age, and distant skeletal and pulmonary disease on diagnostic accuracy were also analyzed.Of the 134 eligible patients, 66 (33 positive and 33 negative for metastasis) were selected for image review and analysis. Whole-body MR imaging did not meet the noninferiority criterion for accuracy when compared with conventional imaging for detection of metastasis (difference between average AUCs was -0.03 [95% confidence interval: -0.10, 0.04]); however, the average AUC for solid tumors was significantly higher than that for lymphomas (P = .006). More skeletal metastases were detected by using whole-body MR imaging than by using conventional imaging (P = .03), but fewer lung metastases were detected (P.001). Patient age did not affect accuracy.The noninferior accuracy for diagnosis of distant metastasis in patients with common pediatric tumors was not established for the use of whole-body MR imaging compared with conventional methods. However, improved accuracy was seen with whole-body MR imaging in patients with nonlymphomatous tumors.

To perform a meta-analysis to evaluate the diagnostic performance of ultrasonography (US) and computed tomography (CT) for the diagnosis of appendicitis in pediatric and adult populations.Medical literature (from 1986 to 2004) was searched for articles on studies that used US, CT, or both as diagnostic tests for appendicitis in children (26 studies, 9356 patients) or adults (31 studies, 4341 patients). Prospective and retrospective studies were included if they separately reported the rate of true-positive, true-negative, false-positive, and false-negative diagnoses of appendicitis from US and CT findings compared with the positive and negative rates of appendicitis at surgery or follow-up. Clinical variables, technical factors, and test performance were extracted. Three readers assessed the quality of studies.Pooled sensitivity and specificity for diagnosis of appendicitis in children were 88% (95% confidence interval [CI]: 86%, 90%) and 94% (95% CI: 92%, 95%), respectively, for US studies and 94% (95% CI: 92%, 97%) and 95% (95% CI: 94%, 97%), respectively, for CT studies. Pooled sensitivity and specificity for diagnosis in adults were 83% (95% CI: 78%, 87%) and 93% (95% CI: 90%, 96%), respectively, for US studies and 94% (95% CI: 92%, 95%) and 94% (95% CI: 94%, 96%), respectively, for CT studies.From the diagnostic performance perspective, CT had a significantly higher sensitivity than did US in studies of children and adults; from the safety perspective, however, one should consider the radiation associated with CT, especially in children.

PURPOSE: To evaluate the ability of fluoroscopic images obtained during air enemas to depict or exclude lead points of intussusceptions and other abnormalities that require surgical treatment in the absence of intussusception. MATERIALS AND METHODS: The clinical, radiologic, surgical, and pathologic findings were reviewed in 14 patients with lead points or other lesions. RESULTS: Fluoroscopic images failed to depict a lead point in 10 patients. The air enema easily reduced intussusceptions with benign lead points in seven patients. Fluoroscopic images depicted pathologic lead points in two patients and were normal in two patients with intussusception. Fluoroscopic images failed to depict an abnormality that required surgery in the absence of intussusception in two patients. CONCLUSION: Successful reduction of an intussusception does not always rule out a lead point. Other imaging studies, the patient's condition, and laparotomy may also be necessary to diagnose and treat lead points and other lesions.

PURPOSE: To evaluate previously described radiologic prognostic factors in extremity osteosarcoma. MATERIALS AND METHODS: In 47 pediatric patients, available images were evaluated for seven prognostic factors at diagnosis and seven additional factors after preoperative chemotherapy. These factors were correlated with histopathologic response and clinical outcome. The association of histopathologic response and outcome was also evaluated. RESULTS: Metastases at presentation and a > 20-cm-diameter soft-tissue mass were predictive of a poor outcome but occurred in few patients. Factors most predictive of < 90% tumor necrosis after chemotherapy included an increase or no change in soft-tissue mass size and increased bone destruction. Although a significant relationship (P < .05) was found between histopathologic response and outcome, no factors predictive of histopathologic response were also predictive of outcome. The accuracy of pathologic response in predicting outcome was 66%. CONCLUSION: Radiologic studi...

To determine the effect of sedative and anesthetic administration on the duration and costs of pediatric magnetic resonance (MR) imaging.This prospective study was approved by the institutional research ethics board; informed consent and/or assent was obtained from all participants or their parents. A patient flow study was conducted in a pediatric MR imaging clinic in which research assistants tracked participants' progress through the clinic. Demographic, visit process, and medication information was collected for 237 participants, categorized as awake, sedated, or anesthetized. The data were analyzed to (a) determine total visit duration differences, (b) investigate variations in visit stage durations according to patient type, and (c) estimate visit costs on the basis of human resource and medication use. Linear regression, the Shapiro-Wilk test, the two-tailed t test, and the nonparametric Mann-Whitney test were used.Complete data sets were obtained for 148 awake, 28 sedated, and 27 anesthetized participants. Data revealed 12 stage sequences among patient visits; dominant sequences differed according to patient category. An awake patient's average visit duration (2 hours 21 minutes) differed significantly from that of sedated (3 hours 38 minutes, P.001) and anesthetized (4 hours 7 minutes, P.001) patients; sedated and anesthetized visit durations did not differ significantly (P.073), although this finding may be attributable to the small sample sizes. Variation in stage durations was also evident within and among patient types. Visit costs for sedated and anesthetized patients were 3.24 and 9.56 times higher, respectively, than those for awake patients. Costs for anesthetized patients were 2.95 times higher than those for sedated patients.Visit durations were significantly longer for anesthetized and sedated patients. Anesthetized patients incurred the highest costs, followed by sedated patients.

To determine whether absence of bowel wall perfusion at color Doppler ultrasonography (US) is indicative of bowel necrosis in neonates with necrotizing enterocolitis (NEC).This study was approved by the research ethics board, and informed consent was obtained. Sixty-two neonates enrolled in the prospective study underwent US of the bowel wall. Neonates were divided into two groups. Group A included 30 control subjects with gestational ages (GAs) ranging from 24 to 41 weeks. Group B included 32 neonates with GAs ranging from 24 to 40 weeks who were clinically proved to have or suspected of having NEC. All neonates in group B underwent abdominal radiography. Normative values were calculated in group A. In group B, the sensitivities and specificities of color Doppler US and abdominal radiography for detection of bowel necrosis were computed by using the modified Bell staging criteria for NEC as the reference standard.Two neonates were excluded from group B; thus, a total of 60 neonates were included in the study. In group A, bowel wall thickness ranged from 1.1 to 2.6 mm. Bowel wall perfusion was detected with color Doppler US in all 30 neonates. Color Doppler signals ranged from one to nine dots per square centimeter. Twenty-two of 30 neonates in group B received a diagnosis of NEC. Mild to moderate NEC was diagnosed in 12 neonates. Color Doppler US depicted an isolated segment of bowel-absent blood flow in two neonates; this finding was confirmed with laparotomy. In 10 neonates with severe NEC, color Doppler US depicted isolated or multiple segments of bowel with absent perfusion. Pneumoperitoneum was present in only four neonates. The remaining eight neonates at risk for NEC had no evidence of loops without perfusion at color Doppler US. The sensitivity of free air at abdominal radiography as a positive sign for severe NEC with necrotic bowel was 40% compared with the 100% sensitivity of absence of flow at color Doppler US (P = .03).Color Doppler US is more accurate than abdominal radiography in depicting bowel necrosis in NEC.