Role of Magnetic Resonance Imaging in the Screening of Closed Spinal Dysraphism.

Closed spinal dysraphism (CSD) encompasses a heterogeneous group of spinal cord deformities, which can be accompanied by several types of skin stigmata. These skin stigmata may include inconspicuous features, such as sacral dimples and deformed gluteal clefts, but the association between such mild skin stigmata and CSD is uncertain. This study aimed to reevaluate the indication for magnetic resonance imaging (MRI) in patients with skin stigmata while considering the indication for surgery. A retrospective analysis was conducted on magnetic resonance images of 1255 asymptomatic children with skin stigmata between 2003 and 2015. Skin stigmata classification was based on medical chart data. All subtypes of CSDs except for filum terminale lipomas (FTL), FTL thicker than 2 mm or with low conus medullaris, were considered to meet the surgical indication. CSD prevalence was estimated while considering the surgical indications and assessed after excluding all FTL cases. Skin stigmata were classified into seven types, dimple, deformed gluteal cleft, hair, subcutaneous mass, appendage, discoloration, and protruding bone, and included 1056 isolated and 199 complex ones. The prevalence of CSD was 19.5%, 6.8%, and 0.5% among patients with isolated dimples (n = 881) and 13.9%, 5.8%, and 0.7% among those with isolated deformed gluteal clefts (n = 136) for all cases, surgical indications, and patients without FTL, respectively. Dimples and deformed gluteal clefts had a low prevalence of CSD requiring surgical intervention, and cases without FTL were rare. Asymptomatic patients with mild skin stigmata may not require immediate MRI.

Usefulness of central radiologic review in clinical trials of children with hepatoblastoma.

BACKGROUND: No previous research papers have reported a comparative survey of local radiologic diagnoses and central review in children with hepatoblastoma. OBJECTIVE: To evaluate the utility of central review of children with hepatoblastoma enrolled in a clinical trial. MATERIALS AND METHODS: The study included 91 children enrolled in a clinical trial conducted by the Japanese Study Group for Pediatric Liver Tumor. We compared the results of the initial pre-treatment extent of tumor (PRETEXT) disease staging performed at local sites with the results obtained on central review to determine the concurrence rates for tumor staging and additional criteria. RESULTS: The concurrence rate for PRETEXT staging was 70%. As the stage increased, the concurrence rate decreased. Using additional criteria, central review identified 143 lesions (157.1%), about 1.8 times higher than the number identified for the local site diagnoses. The additional criterion found most often on central review was "multifocal lesion" (n=19). The concurrence rate for lung metastases was high. However, our central review found many false-positive assertions of hepatic vein lesions, portal vein invasion and extrahepatic lesions among the local site diagnoses. CONCLUSION: In a clinical trial of hepatoblastoma, central review provided a more precise diagnosis than local site diagnoses with respect to severe PRETEXT stages III and IV cases and other cases including hepatic and portal vein invasion. The central review process appears to be effective and essential for improving the quality of clinical trials.

Stage M Infantile Neuroblastoma With Involvement of Falx Cerebri: Case Report and Literature Review.

Neuroblastoma is the most common extracranial solid tumor in children. When metastasis to the falx cerebri is present, it is classified as stage M; however, its behavior has not been well characterized. Here we present a case of stage M infantile neuroblastoma (NB) with involvement of the falx cerebri, and also summarize the clinical profiles of previously reported cases. Notably, all of the tumors resolved with low-dose chemotherapy alone. Although further study is needed to distinguish NBs presenting at these different intracranial locations, NB with metastasis to the falx cerebri may be categorized as MS when diagnosed at less than 18 months of age.

Intraoperative Placement of an Absorbable Spacer Prior to Radiation Therapy for a Malignant Peripheral Nerve Sheath Tumor.

A 7-year-6-month-old female was diagnosed with a pelvic malignant peripheral nerve sheath tumor and lymph node metastases. Tumorectomy was performed after four cycles of chemotherapy. A 33-mm cystic lesion was observed around the left iliac muscle after three cycles of postoperative chemotherapy, and proton beam therapy (PBT) was recommended. She was referred for absorbable spacer (AS) placement. The left ovarian appendage (OA) was resected due to the direct tumor infiltration. The right OA was fixed to the uterosacral ligament. The AS was fixed to the lateral pelvis. The PBT (70.3 Gy relative biological effectiveness) was performed successfully with the AS, and she also had the reproducing possibility due to prevention of severe irradiation damage of the right OA. AS eliminated the surgical removal of spacers and enabled us high-dose PBT for residual tumor without severe irradiation damage including infertility.

Value of parametric indexes to identify tracheal atresia with or without fistula on fetal magnetic resonance imaging.

BACKGROUND: Tracheal atresia causes some secondary changes (dilated trachea, flattened/inverted diaphragm, hyperintense and hyperinflated lungs). They can be reduced if a high airway fistula is present. OBJECTIVE: This study evaluated fetal MR images of tracheal atresia and the secondary changes, focusing on the presence of a fistula. MATERIALS AND METHODS: We assessed fetal MR images of tracheal atresia without fistula (n=4, median 26 weeks), tracheal atresia with fistula (n=4, median 33 weeks) and controls (n=30, median 32 weeks). We evaluated airway obstruction using true-positive rate in tracheal atresia and false-positive rate in controls indicating they are likely normal variants. Tracheal diameter, craniocaudal-anteroposterior ratio of the right hemidiaphragm, lung-to-liver signal intensity ratio, and cardiothoracic ratio were compared among the three groups using the Kruskal-Wallis test followed by pairwise comparison using the Mann-Whitney U test. RESULTS: True-positive rate was 100% in tracheal atresia, while false-positive rate was 20% in controls. The Kruskal-Wallis test showed differences among groups in craniocaudal-anteroposterior ratio and cardiothoracic ratio (P<0.001) but not in tracheal diameter (P=0.256) or lung-to-liver signal intensity ratio (P=0.082). The pairwise comparison in craniocaudal-anteroposterior ratio and cardiothoracic ratio showed differences between controls and tracheal atresia without fistula (P<0.01) and with fistula (P<0.05). CONCLUSION: Fetal MRI is useful for the diagnosis of tracheal atresia, and detection of airway obstruction is essential. Lower craniocaudal-anteroposterior ratio and cardiothoracic ratio might be reliable measures even if a fistula is present.

"Follow the Fallopian tube": A technique to improve sonographic identification of ovaries in children.

Ovary detection is the first step in confirming ovarian lesions. The daughter cyst sign is widely used for this purpose; however, it is not always applicable. Recent improvements in image resolution allow Fallopian tube delineation, which can serve as a guide to identify the ovary. This anatomical approach ("follow the Fallopian tube" technique) comprises three steps: (1) confirm the uterus; (2) follow the Fallopian tube; and (3) find the ovary. Other applications of this approach include the differentiation between nonovarian and ovarian masses and ruling out ovarian torsion and an auto-amputated ovary.

Acute hematogenous pelvic osteomyelitis: appropriate timing for magnetic resonance imaging.

BACKGROUND: The precise time of appearance of bone marrow edema in acute hematogenous pelvic osteomyelitis (AHPO) is unknown. The purpose of the present research is to clarify the time of appearance of bone marrow edema on magnetic resonance imaging (MRI) in AHPO. Our hypothesis was that onset is slower than in long-bone osteomyelitis. METHODS: We selected 12 patients (mean, 11.8 years) with MRI findings and clinical diagnosis of AHPO. The signal ratios of bone marrow (BM) and gluteus maximus muscle (M, BM/M ratio) in fat-suppressed T2- and T1-weighted images (T2WI, T1WI) were calculated to evaluate changes in bone-marrow signals. The correlation between BM/M ratios and days from onset was evaluated statistically and compared with lower extremity osteomyelitis. RESULTS: Bone marrow/M ratio of T2WI increased over time after the onset of the primary symptom in all patients and showed a statistically positive correlation (r = 0.36). In seven patients in whom an MRI scan was conducted twice, all showed higher values for the second MRI, and changes were more pronounced over time. The mean BM/M ratio of T2WI was 4.1 when 7 days or less had elapsed from the primary symptom, and 6.4 when more than 7 days had elapsed. The BM/M ratios in the sacroiliac joint group were lower than in the non-sacroiliac joint group. CONCLUSIONS: Unlike long-bone osteomyelitis, it took 1 week before findings for AHPO became fully evident. A definitive diagnosis can be made in patients with suspected sacroiliitis by performing a further MRI scan at 7 days or later.

Mediastinal and hilar soft tissue mass-like lesions in congenital unilateral pulmonary vein atresia: A retrospective review of seven pediatric patients.

BACKGROUND: Congenital unilateral pulmonary vein atresia (CUPVA) is known to lead to the formation of an abnormal confluent mediastinal and hilar soft tissue mass, thoracic hypoplasia, and interlobular septal thickening on the affected side. The purpose of the present study is to investigate the frequency and severity of mediastinal soft tissue mass-like lesions and examine other abnormal findings associated with CUPVA. METHODS: We retrospectively reviewed seven children with CUPVA who underwent contrast-enhanced CT scans and measured the soft tissue mass volume in the bilateral mediastinum (affected and normal side). The location of abnormal soft tissue was divided into three anatomical sections (paratracheal, peribronchial, and the dorsal aspect of the left atrium). The relationships among soft tissue volume and anatomical section were statistically evaluated. Also, the presence of thoracic hypoplasia, small ipsilateral pulmonary arteries, interlobular septal thickening, and ground-glass opacities were investigated. RESULTS: In all cases, CT scans confirmed the presence of confluent soft tissue mass-like lesions in the affected mediastinum. The soft tissue volume on the affected side was 5.5-fold greater than the volume on the normal side (average: 18.0 cm3 and 4.25 cm3 respectively, P < 0.01). Thoracic hypoplasia and interlobular septal thickening were found in all patients. Small pulmonary arteries and ground-glass opacities were present in six of the seven patients. CONCLUSION: Abnormal mediastinal and hilar soft tissue is commonly found in patients with CUPVA. So, if we encounter the mediastinal soft tissue mass in patients with CUPVA, no further test will be indicated.