Effect of Intravenous Administration of Contrast Media on Serum Creatinine Levels in Neonates.

Purpose To assess the effect of intravenous contrast media on renal function in neonates. Materials and Methods Institutional review board approval was obtained with waiver of consent. Electronic health records from January 2011 to April 2013 were reviewed retrospectively. Measures of renal function were obtained in inpatient neonates who underwent magnetic resonance (MR) imaging or computed tomography (CT) and for whom serum creatinine (Cr) levels were obtained within 72 hours before imaging and at least one time after imaging (>1 day after administration of contrast material). A total of 140 neonates who received contrast material (59 who underwent CT with iohexol or iodixanol and 81 who underwent MR imaging with gadopentetate dimeglumine) were identified. These neonates were frequency matched according to sex, gestational and postnatal age, and preimaging serum Cr levels with neonates who underwent unenhanced MR imaging or CT. Cr levels and glomerular filtration rates (GFRs) were grouped according to when they were obtained (before imaging, 1-2 days after imaging, 3-5 days after imaging, 6-9 days after imaging, 10-45 days after imaging, and more than 45 days after imaging). Serum Cr levels and GFRs for each time period were compared between groups by using hierarchic regressions or χ2 or Fisher exact tests and with repeated-measures analysis of variance to compare groups on the rate of change in serum Cr levels and GFRs from before to after imaging. Results Cr levels decreased and GFRs increased in both groups from before to after imaging (CT group, P ≤ .01; MR imaging group, P ≤ .01). The neonates who underwent contrast material-enhanced imaging and the neonates who underwent unenhanced imaging showed similar serum Cr levels at all examined time periods. Groups also did not differ in the proportion of neonates with serum Cr levels higher than the reference range (>0.4 mg/dL) at any time point (iodine- [P > .12] or gadolinium-based [P > .13] contrast material). Similar findings were observed for GFRs. None of the neonates developed nephrogenic systemic fibrosis. Conclusion In the absence of known renal failure, neonates receiving standard inpatient care do not appear to be at increased risk for developing renal toxicity due to administration of intravenous iodine- and gadolinium-based contrast material. © RSNA, 2017.

Comparative evaluation of local control strategies in localized Ewing sarcoma of bone: a report from the Children's Oncology Group.

BACKGROUND: Patients with Ewing sarcoma require local primary tumor control with surgery, radiation, or both. The optimal choice of local control for overall and local disease control remains unclear. METHODS: Patients with localized Ewing sarcoma of bone who were treated on 3 consecutive protocols with standard-dose, 5-drug chemotherapy every 3 weeks were included (n=465). Propensity scores were used to control for differences between local control groups by constructing multivariate models to assess the impact of local control type on clinical endpoints (event-free survival [EFS], overall survival, local failure, and distant failure) independent of differences in their propensity to receive each local control type. RESULTS: Patients who underwent surgery were younger (P=.02) and had more appendicular tumors (P<.001). Compared with surgery, radiation had higher unadjusted risks of any event (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.18-2.44), death (HR, 1.84; 95% CI, 1.18-2.85), and local failure (HR, 2.57; 95% CI, 1.37-4.83). On multivariate analysis, compared with surgery, radiation had a higher risk of local failure (HR, 2.41; 95% CI, 1.24-4.68), although there were no significant differences in EFS (HR, 1.42; 95% CI, 0.94-2.14), overall survival (HR, 1.37; 95% CI, 0.83-2.26), or distant failure (HR, 1.13; 95% CI, 0.70-1.84) between local control groups. CONCLUSIONS: In this large group of similarly treated patients, choice of the mode of local control was not related significantly to EFS, overall survival, or distant failure, although the risk of local failure was greater for radiation compared with surgery. These data support surgical resection when appropriate, whereas radiotherapy remains a reasonable alternative in selected patients.

Skeletal muscles of ambulant children with Duchenne muscular dystrophy: validation of multicenter study of evaluation with MR imaging and MR spectroscopy.

PURPOSE: To validate a multicenter protocol that examines lower extremity skeletal muscles of children with Duchenne muscular dystrophy (DMD) by using magnetic resonance (MR) imaging and MR spectroscopy in terms of reproducibility of these measurements within and across centers. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review boards of all participating centers, and informed consent was obtained from each participant or a guardian. Standardized procedures with MR operator training and quality assurance assessments were implemented, and data were acquired at three centers by using different 3-T MR imaging instruments. Measures of maximal cross-sectional area (CSAmax), transverse relaxation time constant (T2), and lipid fraction were compared among centers in two-compartment coaxial phantoms and in two unaffected adult subjects who visited each center. Also, repeat MR measures were acquired twice on separate days in 30 boys with DMD (10 per center) and 10 unaffected boys. Coefficients of variation (CVs) were computed to examine the repeated-measure variabilities within and across centers. RESULTS: CSAmax, T2 from MR imaging and MR spectroscopy, and lipid fraction were consistent across centers in the phantom (CV, <3%) and in the adult subjects who traveled to each site (CV, 2%-7%). High day-to-day reproducibility in MR measures was observed in boys with DMD (CSAmax, CV = 3.7% [25th percentile, 1.3%; 75th percentile, 5.1%]; contractile area, CV = 4.2% [25th percentile, 0.8%; 75th percentile, 4.9%]; MR imaging T2, CV = 3.1% [25th percentile, 1.2%; 75th percentile, 4.7%]; MR spectroscopy T2, CV = 3.9% [25th percentile, 1.5%; 75th percentile, 5.1%]; and lipid fraction, CV = 4.7% [25th percentile, 1.0%; 75th percentile, 5.3%]). CONCLUSION: The MR protocol implemented in this multicenter study achieved highly reproducible measures of lower extremity muscles across centers and from day to day in ambulatory boys with DMD.

ACR Appropriateness Criteria® limping child--ages 0 to 5 years.

The appropriate imaging for pediatric patients (ages 0-5 years) being evaluated for limping depends on the clinical presentation, specifically, the presence of signs of infection, any localization of pain, and history of or suspected trauma. Common diagnoses causing limping in children are briefly reviewed, and recommended imaging techniques are discussed, including toddler's fracture, transient synovitis, septic arthritis, Legg-Calvé-Perthes disease, and osteomyelitis. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Imaging modalities in pediatric oncology.

This article reviews the roles of specific imaging modalities in the diagnosis and management of noncentral nervous system childhood cancer. Imaging modalities to be discussed include conventional radiography, ultrasound, computed tomography, magnetic resonance imaging, and nuclear medicine, including positron emission tomography. Emerging imaging techniques will also be discussed. Current literature will be referenced for more in-depth review.

ACR Appropriateness Criteria(®) on suspected physical abuse-child.

The appropriate imaging for pediatric patients being evaluated for suspected physical abuse depends on the age of the child, the presence of neurologic signs and symptoms, evidence of thoracic or abdominopelvic injuries, and whether the injuries are discrepant with the clinical history. The clinical presentations reviewed consider these factors and provide evidence-based consensus recommendations by the ACR Appropriateness Criteria(®) Expert Panel on Pediatric Imaging.

CR/PACS for scoliosis: a turn for the better?

As radiology departments convert to digital imaging, the acquisition, reading,and management of scoliosis studies pose unique challenges. This case study assesses the actual impact on efficiency,file management, cost, and clinical acceptability after a conversion to see whether goals were accomplished. As digital imaging for scoliosis studies became the new standard of care in the Children's Hospital of Philadelphia radiology department, it renewed interest and attention to these disorders and facilitated improved patient care.

Musculoskeletal MR imaging at 3 T.

MR imaging plays a major role in the assessment of pediatric musculoskeletal disease. Compared with 1.5 T MR imaging, 3 T magnets provide images with an increased signal-to-noise ratio, which is particularly helpful when assessing small body parts and structures in children. This article discusses the advantages and challenges associated with musculoskeletal MR imaging at 3 T, basic scanning protocols, image optimization techniques, and specific clinical applications in a pediatric population.

Imaging guidelines for children with Ewing sarcoma and osteosarcoma: a report from the Children's Oncology Group Bone Tumor Committee.

The Children's Oncology Group (COG) is a multi-institutional cooperative group dedicated to childhood cancer research that has helped to increase the survival of children with cancer through clinical trials. These clinical trials include a standardized regimen of imaging examinations performed prior to, during, and following therapy. This article presents imaging guidelines developed by a multidisciplinary group from the COG Bone Tumor Committee. These guidelines provide both required and recommended studies. Recommended examinations may become required in the future. These guidelines should be considered a work in progress that will evolve with advances in imaging and childhood cancer research.

Lack of association of CT findings and surgical drainage in pediatric neck abscesses.

OBJECTIVE: To evaluate the relationship between neck abscess characteristics on computerized tomography (CT) scan and surgical drainage in pediatric patients. METHODS: Retrospective data warehouse review identified 43 children younger than 19 years admitted to a tertiary care pediatric hospital during the first quarters of 2000 through 2003 who underwent CT imaging for suspicion of head and neck abscesses involving the neck; face; and peritonsillar, retropharyngeal, and parapharyngeal spaces. A total of 45 scans were graded by a radiologist blinded to management. Thickness of the prevertebral soft tissue; location, dimensions, and degree of enhancement of the abscess; patient age; steroid and preadmission antibiotic use; and surgical intervention were recorded. RESULTS: Surgical drainage was performed in 32 of 43 patients (74%). We found no significant correlation between prevertebral soft tissue thickness, abscess dimensions or enhancement on CT scan, and surgical drainage. There was no significant association between surgical drainage and patient age, administration of steroids, or preadmission antibiotic use. CONCLUSIONS: Neck abscess appearance on CT scan did not predict surgical drainage, although prevertebral soft tissue thickness and abscess dimensions may be important features. Abscess enhancement, patient age, and the use of steroids and prehospitalization antibiotics were not found to correlate with surgical drainage.

Which MRI sequence of the spine best reveals bone-marrow metastases of neuroblastoma?

BACKGROUND: MRI is an effective tool in evaluating bone marrow metastases. However, no study has defined which MRI sequences or image characteristics best correlate with bone-marrow metastases in neuroblastoma. OBJECTIVE: To identify and refine MRI criteria and sequence selection for the diagnosis of bone-marrow metastases in children with neuroblastoma. MATERIALS AND METHODS: Ninety-one children (mean age: 3.2 years; standard deviation: 2.8 years) enrolled in the RDOG IV study participated in our study. Forty-five children had bone metastases determined by bone-marrow aspiration or biopsy (n=4), radionuclide imaging (n=2), or both (n=39). Spine lesions were characterized using coronal T1-weighted (T1W) sagittal short tau inversion recovery (STIR) and coronal gadolinium-enhanced T1-weighted (GAD) MR sequences. Contingency table analysis was performed to determine which MRI sequences and characteristics were associated with metastases. The MRI criteria for metastatic disease were then developed for each imaging sequence. The sensitivity, specificity, predictive values, and accuracy of these criteria were determined for the whole group, children younger than 12 months old, and children 12 months and older. RESULTS: The MR characteristics that had significant (P

Malignant bone tumors and limb-salvage surgery in children.

Limb-salvage surgery plays a major role in the management of children with malignant bone tumors. This article provides background on the clinical presentation and imaging evaluation of children with malignant bone tumors and describes various limb-salvage procedures used in the treatment of these children.

Role of magnetic resonance imaging and clinical criteria in predicting successful nonoperative treatment of osteochondritis dissecans in children.

Magnetic resonance imaging (MRI) offers promise as a noninvasive method to determine the potential of an osteochondritis dissecans (OCD) lesion to heal without surgical intervention. The purpose of this study was to compare the value of MRI, plain radiographs, and clinical findings in predicting the success of nonoperative treatment of juvenile OCD lesions. Twenty-seven lesions in 24 patients (mean age 12.2 y) with OCD of the distal femur diagnosed based on MRI were identified. A radiologist or orthopaedist, blinded to the clinical status of the patients, correlated the MRIs with patient outcome. MRIs were assessed for lesion size, location, and four criteria evaluating signal intensity changes and articular surface defects to determine lesion stability. Older, more skeletally mature patients with at least one sign of instability on MRI were most likely to have nonoperative treatment fail. Nonoperative treatment failed most often in patients with large lesions in weightbearing areas, as seen on lateral radiographs. However, location based on anteroposterior radiographs was not statistically significant for predicting treatment outcome. Although no single factor was uniformly predictive of successful nonoperative treatment, younger, skeletally immature patients with no MRI criteria of instability were most amenable to nonoperative treatment.

Imaging of neuroblastoma and Wilms' tumor.

Neuroblastoma and Wilms' tumor are the most common noncentral nervous system solid tumors in children. Imaging plays a crucial role in the evaluation of the primary tumor and regional and metastatic disease. There is a growing body of literature supporting the use of MRI as the technique of choice for the evaluation of local and regional disease in children with suspected neuroblastoma; however, in children with suspected Wilms' tumor, MRI will likely continue to play a role as a problem-solver when the results of CT are equivocal or indeterminant.

Ultrasound of a torsed ovary: characteristic gray-scale appearance despite normal arterial and venous flow on Doppler.

BACKGROUND: We present the case of an 8-year-old girl with acute onset of intermittent lower abdominal pain. The gray-scale US examination showed an enlarged right ovary with peripheral cysts, reflecting ovarian congestion and strongly suggesting the diagnosis of torsion. Normal arterial and venous flow, however, was found on Doppler US. OBJECTIVE: To demonstrate the importance of gray-scale US findings despite the presence of blood flow found on Doppler US in salvaging a viable, torsed ovary. METHODS: Despite the Doppler findings, a presumptive diagnosis of ovarian torsion was made. RESULTS: Surgery confirmed the presence of a torsed ovary, which was viable and appeared normal after detorsion. CONCLUSION: This case illustrates that the gray-scale US appearance of the ovary can be more reliable than Doppler US for the diagnosis of ovarian torsion.

Staging of neuroblastoma at imaging: report of the radiology diagnostic oncology group.

PURPOSE: To compare the accuracies of computed tomography (CT), magnetic resonance (MR) imaging, and bone scintigraphy in staging disease in patients with neuroblastoma. MATERIALS AND METHODS: Ninety-six children with newly diagnosed neuroblastoma were enrolled in a multicenter prospective cohort study. CT, MR, and bone scintigraphy were used to evaluate tumor stage. Sensitivity and specificity values and receiver operating characteristic (ROC) curve analyses were used to compare the accuracy of CT, MR, and scintigraphy for tumor staging. RESULTS: Eighty-eight patients were eligible for staging analysis, and 45 patients who underwent surgery at initial diagnosis were eligible for analysis of local tumor extent. CT and MR had sensitivities of 43% and 83%, respectively (P <.01), and specificities of 97% and 88%, respectively (P >.05), for detection of stage 4 disease. Areas under the ROC curves for CT and MR were 0.81 and 0.85, respectively (P =.06); that for scintigraphy was 0.83. Addition of scintigraphy to both CT and MR increased the areas under the ROC curves to 0.90 and 0.88, respectively. Accuracy of CT and MR for staging disease confined to the chest or abdomen (stages 1, 2, and 3) was poor. CONCLUSION: MR alone and CT and MR combined with bone scintigraphy enable the accurate detection of stage 4 disease. Both CT and MR perform poorly for local tumor staging.