MRI for Pediatric Appendicitis in an Adult-Focused General Hospital: A Clinical Effectiveness Study-Challenges and Lessons Learned.

OBJECTIVE: The objective of our study was to determine the feasibility and accuracy of MRI for pediatric appendicitis in an adult-predominant general hospital setting where non-pediatric-trained radiologists routinely interpret the studies. MATERIALS AND METHODS: MRI was performed in pediatric patients with equivocal ultrasound (US) findings and persistent clinical concern for appendicitis. Neither IV contrast material nor a sedative was administered. Our MRI protocol evolved early during the study period, quickly settling on three sequences (total scanning time, 11 minutes). The clinical reference standard for statistical analysis was appendicitis diagnosed on operative or pathology report; 95% Clopper-Pearson CIs were calculated. RESULTS: Between 2012 and 2016, 528 pediatric patients (mean age, 9.9 years; age range, 1-17 years) underwent MRI after US evaluation yielded equivocal findings: 10.4% (55/528) of patients were found to have surgically proven or pathologically proven appendicitis. Sensitivity and specificity of MRI for appendicitis were 96.4% and 98.9%, respectively. Positive and negative predictive values were 91.2% and 99.6%. A normal appendix and abnormalities not involving the appendix were identified on MRI in 21.6% (114/528) of patients. CONCLUSION: Our data show that unenhanced MRI for suspected appendicitis in pediatric patients is clinically effective when performed in a nonpediatric hospital setting with nonpediatric radiologists, emergency physicians, and surgeons.

MRA Mapping and Selective Embolization of a Large Uterine Cavity Pseudoaneurysm at 20 Weeks of Gestation.

Antepartum uterine cavity pseudoaneurysm rupture can cause massive hemorrhage with high maternal and fetal mortality risk. Invasive placentation can predispose to vascular malformations. We present a novel use of macrocyclic intravenous contrast-enhanced magnetic resonance angiography for preprocedure planning followed by selective low radiation embolization of a uterine cavity pseudoaneurysm in the setting of invasive placentation at 20 weeks of gestation. To our knowledge, this is the first reported case of uterine cavity pseudoaneurysm successfully mapped with MRA and treated with embolization at 20 weeks of gestation.

Increased Intracranial Pressure in a Boy with Gorham-Stout Disease.

Gorham-Stout disease (GSD), also known as vanishing bone disease, is a rare disorder, which most commonly presents in children and young adults and is characterized by an excessive proliferation of lymphangiomatous tissue within the bones. This lymphangiomatous proliferation often affects the cranium and, due to the proximate location to the dura surrounding cerebrospinal fluid (CSF) spaces, can result in CSF leaks manifesting as intracranial hypotension with clinical symptoms to include orthostatic headache, nausea, and vertigo. We present the case of a boy with GSD and a known history of migraine headaches who presented with persistent headaches due to increased intracranial pressure. Although migraine had initially been suspected, he was eventually diagnosed with intracranial hypertension after developing ophthalmoplegia and papilledema. We describe the first known instance of successful medical treatment of increased intracranial pressure in a patient with GSD.

Primary leptomeningeal lymphoma of the lumbar spine.

This report describes primary leptomeningeal lymphoma (PLML) of the spine in a 58-year-old female. LML is rare, especially in the immunocompetent, and it is almost always secondary in origin. To our knowledge, there have been very few cases of PLML of the lumbar spine reported in the literature and even fewer reports using recent MR imaging (MRI) technology to aid with diagnosis. MRI is useful in differentiating CNS lesions and may be helpful in the diagnosis of this extremely rare primary lymphoma. PLML is briefly reviewed.

Neuroblastoma, ganglioneuroblastoma, and ganglioneuroma: radiologic-pathologic correlation.

Neuroblastoma, ganglioneuroblastoma, and ganglioneuroma are tumors of the sympathetic nervous system that arise from primitive sympathogonia and are referred to collectively as neuroblastic tumors. They arise wherever sympathetic tissue exists and may be seen in the neck, posterior mediastinum, adrenal gland, retroperitoneum, and pelvis. The three tumors differ in their degree of cellular and extracellular maturation; immature tumors tend to be aggressive and occur in younger patients (median age, just under 2 years), whereas mature tumors occur in older children (median age, approximately 7 years) and tend to behave in a benign fashion. The most benign tumor is the ganglioneuroma, which is composed of gangliocytes and mature stroma. Ganglioneuroblastoma is composed of both mature gangliocytes and immature neuroblasts and has intermediate malignant potential. Neuroblastoma is the most immature, undifferentiated, and malignant tumor of the three. Neuroblastoma, however, may have a relatively benign course, even when metastatic. Thus, these neuroblastic tumors vary widely in their biologic behavior. Features such as DNA content, tumor proto-oncogenes, and catecholamine synthesis influence prognosis, and their presence or absence aids in categorizing patients as high, intermediate, or low risk. Treatment consists of surgery and, usually, chemotherapy. Despite recent advances in treatment, including bone marrow transplantation, neuroblastoma remains a relatively lethal tumor, accounting for 10% of pediatric cancers but 15% of cancer deaths in children.