Usefulness of diffusion-weighted MRI in the initial assessment of osseous sarcomas in children and adolescents.

BACKGROUND: Concern regarding gadolinium deposition in the brain after repeated administration of intravenous gadolinium-based contrast agents has prompted evaluation of imaging alternatives. OBJECTIVE: The study purpose was to determine if magnetic resonance imaging (MRI) using conventional sequences with diffusion-weighted imaging (DWI) instead of gadolinium-based contrast-enhanced MRI is valid for local staging and guiding biopsies in osseous sarcomas. MATERIALS AND METHODS: Initial pretreatment MRI with DWI and gadolinium-based contrast-enhanced images in patients ≤ 18 years with histopathologically proven osseous sarcomas were included. Two radiologists blinded to collated demographic and clinical data, independently reviewed conventional/DWI and conventional/gadolinium-based contrast-enhanced MRI then conventional sequences alone, recording tumor size, skip lesions, necrosis, neurovascular invasion, enlarged lymph nodes and diffusion restriction. Discrepancies were resolved by a third reader. A single reader measured apparent diffusion coefficient (ADC) values in non-necrotic tumors, then correlated minimum ADC values -- with and without normalization to skeletal muscle -- with relative enhancement. RESULTS: Twenty-one patients (mean age: 11.3±4.2 years, 15 [71%] females) had 14 osteosarcomas and 7 Ewing sarcomas, 50% centered in the femur. Conventional/DWI versus conventional/gadolinium-based contrast-enhanced MRI showed agreement for tumor size estimation with significant associations for necrosis (P=0.021), neurovascular involvement (P<0.001) and enlarged lymph nodes (P=0.005). Diagnostic accuracy of conventional/DWI is comparable to conventional/gadolinium-based contrast-enhanced MRI and superior to conventional sequences alone. Comparison between minimum ADC values and relative enhancement showed no correlation (P>0.05). CONCLUSION: Significant associations of key imaging features in the initial assessment of osseous sarcomas support DWI as an alternative to gadolinium-based contrast-enhanced MRI. The lack of association between ADC values and relative enhancement suggests that they measure independent constructs, DWI dependent upon tumor cellularity and perfusion.

Pediatric spine imaging post scoliosis surgery.

Many orthopedic articles describe advances in surgical techniques and implants used in pediatric scoliosis surgery. However, even though postoperative spine imaging constitutes a large portion of outpatient musculoskeletal pediatric radiology, few, if any, radiology articles discuss this topic. There has been interval advancement over the last decades of the orthopedic procedures used in the treatment of spinal scoliosis in adolescents with idiopathic scoliosis. The goal of treatment in these patients is to stop the progression of the curve by blocking the spinal growth and correcting the deformity as much as possible. To that end, the authors in this paper discuss postoperative imaging findings of Harrington rods, Luque rods, Luque-Galveston implants and segmental spinal fusion systems. Regarding early onset scoliosis, the guiding principles used for adolescent idiopathic scoliosis do not apply to a growing spine because they would impede lung development. As a result, other devices have been developed to correct the curve and to allow spinal growth. These include spine-based growing rods, vertically expandable prosthetic titanium rods (requiring repetitive surgeries) and magnetically controlled growing rods (with a magnetic locking/unlocking system). Other more recent systems are Shilla and thoracoscopic anterior vertebral body tethering, which allow guided growth of the spine without repetitive interventions. In this paper, we review the radiologic appearances of different orthopedic implants and techniques used to treat adolescent idiopathic scoliosis and early onset scoliosis. Moreover, we present the imaging findings of the most frequent postoperative complications.

Small bowel obstruction due to ingestion of rubber balls.

We report a case of a 10-month-old girl who presented with a 10-day history of emesis that became bilious on the last day. The initial evaluation suggested small bowel obstruction. An upper gastrointestinal study confirmed the normal location of the duodenojejunal junction with normal rotation and no evidence of midgut volvulus. Ultrasound (US) evaluation demonstrated two intraluminal lesions that do not follow the typical features of solid or cystic lesions. Two rubber balls were found at surgery to be responsible for the small bowel obstruction. Foreign body ingestion is common in children, but this case demonstrates a unusual foreign object to be ingested as well as the US appearance of this particular foreign body.

Monogenic autoinflammatory diseases in children: single center experience with clinical, genetic, and imaging review.

PURPOSE: 1. To review the contemporary literature and present a list of the imaging findings for patients with autoinflammatory diseases from our hospital. All these patients are found to have a genetic mutation that is responsible for their disease. 2. To present follow-up imaging findings, when available, and correlate those with symptoms and type of treatment administered in approximately 40 patients with autoinflammatory diseases of a single tertiary pediatric health care center including familial Mediterranean fever, Cryopyrin-associated autoinflammatory syndrome, PAPA (pyogenic arthritis, pyoderma gangrenousum, and acne) syndrome, and more. These findings are related to disease progression, treatment response, or treatment-induced changes. CONCLUSION: Autoinflammatory diseases are relatively rare entities that can affect any system of the body. Given the many nonspecific imaging features, awareness of these diseases and good communication with clinicians aid in reaching an accurate diagnosis.

Magnetic Resonance Cholangiopancreatography Severity Predicts Disease Outcomes in Pediatric Primary Sclerosing Cholangitis: A Reliability and Validity Study.

Magnetic resonance cholangiopancreatography (MRCP) has not been assessed as a surrogate biomarker in pediatrics. We aimed to determine the inter-rater reliability, prognostic utility, and construct validity of the modified Majoie endoscopic retrograde cholangiopancreatography classification applied to MRCP in a pediatric primary sclerosing cholangitis (PSC) cohort. This single-center, retrospective, cohort study included children with PSC undergoing diagnostic MRCP between 2008 and 2016. Six variations of the Majoie classification were examined: 1) intrahepatic duct (IHD) score, 2) extrahepatic duct (EHD) score (representing the worst intrahepatic and extrahepatic regions, respectively), 3) sum IHD-EHD score, 4) average IHD score, 5) average EHD score, and 6) sum average IHD-EHD score. Inter-rater reliability was assessed using weighted kappas and intraclass correlation coefficients (ICCs). Ability to predict time to PSC-related complications (ascites, esophageal varices, variceal bleed, liver transplant [LT], or cholangiocarcinoma) (primary outcome) and LT (secondary outcome) was assessed with Harrell's concordance statistic (c-statistic) and univariate/multivariable survival analysis. Construct validity was further assessed with Spearman correlations. Forty-five children were included (67% boys; median, 13.6 years). The inter-rater reliability of MRCP scores was substantial to excellent (kappas/ICCs, 0.78-0.82). The sum IHD-EHD score had the best predictive ability for time to PSC complication and LT (c-statistic, 0.80 and SE, 0.06; and c-statistic, 0.97 and SE, 0.01, respectively). Higher MRCP scores were independently associated with a higher rate of PSC-related complications, even after adjusting for the PSC Mayo risk score (hazard ratio, 1.74; 95% confidence interval, 1.14-2.). MRCP sum scores correlated significantly with METAVIR fibrosis stage, total bilirubin, and platelets (r = 0.42, r = 0.33, r = -0.31, respectively; P < 0.05). Conclusion: An MRCP score incorporating the worst affected intrahepatic and extrahepatic regions is reliable and predicts meaningful outcomes in pediatric PSC. Next steps include prospective validation and responsiveness assessment.

Monophasic synovial sarcoma presenting as a primary ileal mass: a case report and review of the literature.

INTRODUCTION: Synovial sarcoma is a rare malignant mesenchymal tumor mainly arising in the peri-articular tissue in young adults. There are few cases reported in other areas. CASE PRESENTATION: We report the case of a 29-year-old Saudi woman of Arabian ethnicity with synovial sarcoma arising primarily from the ileum who presented with abdominal pain, a palpable mass and incomplete intestinal obstruction. A literature review was performed to gather information on this rare gastrointestinal tract sarcoma. CONCLUSIONS: Although it is a rare tumor of the pre-articular tissues, synovial sarcoma can present, in exceedingly rare cases, in unusual anatomical sites such as the gastrointestinal tract. We believe the reporting of all rare or unexpected presentations of sarcoma will eventually improve our understanding of this relatively unusual malignancy.