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The target sign on T2-weighted MR imaging is helpful in differentiating neurofibromas from malignant peripheral nerve sheath tumors.

Islet allotransplantation can provide insulin independence in selected individuals with type 1 diabetes. The long-term effects of these transplants on the liver are unknown. Recently, two cases of periportal steatosis after islet transplantation have been described. In this study, we performed ultrasound and magnetic resonance imaging (MRI) in 30 C-peptide؊positive islet transplant recipients to detect steatosis and to explore the association of the radiological findings with clinical and metabolic factors. Steatosis was observed on MRI in six (20%) subjects. Histological findings of hepatic steatosis concurred with the imaging findings. Steatosis completely resolved in one subject whose graft failed. More subjects with steatosis required supplementary exogenous insulin than not (67 vs. 21%; P < 0.05). The clinical features of subjects with and without steatosis were otherwise similar, although C-peptide levels were higher in insulin-independent subjects with steatosis S uccessful islet transplantation using a steroidfree, sirolimus-based immunosuppressive regimen (the Edmonton protocol) has emerged as an effective treatment for type 1 diabetic subjects at major risk from hypoglycemia and metabolic lability (1). Although islet autotransplants have functioned for Ͼ18 years without clinical consequence, the long-term effects of persistent allotransplanted islets on the liver after portal venous delivery have not been well defined in large patient cohorts.Clearly a number of factors might result in structural/ functional changes in the liver: 1) the procedure itself, including ablative approaches used to prevent bleeding from the catheter tract; 2) the physical embolization of terminal branches of the portal vein by islets and the local effects of peri-islet micro-thrombi; 3) the local effects on the hepatocyte of high concentrations of insulin released from the transplanted islets; 4) the effects of immunosuppressive drugs on the liver; and 5) structural changes, including local scarring after rejection and clearance of islet tissue within the liver. Ultrasound and magnetic resonance imaging (MRI) are noninvasive techniques that facilitate definition of hepatic structure and can be repeated safely to follow changes over time.An examination of radiological changes after islet transplantation is important for the clinical care of transplant patients and to learn more about the function of transplanted islets over time. Knowledge of normal abdominal appearance after islet transplantation is helpful for future interpretation when these patients present with abdominal pathology unrelated to their islet transplant.Recently, two cases of periportal steatosis after intraportal islet allotransplantation, apparent on MRI examination, have been described in a small series of four subjects (2). The appearance of steatosis was attributed to intrahepatic insulin secretion and was proposed as a marker of functional islet graft survival. Preliminary data from Maafi et al. (3) also have demonstrated both ultrasonographic and histo...

Malnutrition is a common complication in patients with end‐stage liver disease (ESLD) awaiting liver transplantation (LT). Malnutrition and sarcopenia overlap in etiology and outcomes, with sarcopenia being defined as reduced skeletal muscle mass and muscle function. The purpose of this review was to identify the prevalence of sarcopenia with and without obesity in adults and children with ESLD and to assess the methodological considerations in sarcopenia diagnosis and the association of sarcopenia with pre‐ and post‐LT outcomes. A total of 38 articles (35 adult and 3 pediatric articles) retrieved from PubMed or Web of Science databases were included. In adults, the prevalence rates of pre‐LT sarcopenia, pre‐LT sarcopenic obesity (SO), post‐LT sarcopenia, and post‐LT SO were 14%‐78%, 2%‐42%, 30%‐100%, and 88%, respectively. Only 2 adult studies assessed muscle function in patients diagnosed with sarcopenia. The presence of pre‐LT sarcopenia is associated with higher wait‐list mortality, greater postoperative mortality, higher infection risk and postoperative complications, longer intensive care unit (ICU) stay, and ventilator dependency. The emerging pediatric data suggest that sarcopenia is prevalent in pre‐ and post‐LT periods. In 1 pediatric study, sarcopenia was associated with poor growth, longer perioperative length of stay (total/ICU) and ventilator dependency, and increased rehospitalization in children after LT. In conclusion, there is a high prevalence of sarcopenia in adults and children with ESLD. Sarcopenia is associated with adverse clinical outcomes. The present review is limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing sarcopenia. Future studies are needed to standardize the sarcopenia diagnosis and muscle function assessment, particularly in the pediatric population, to enable early identification and treatment of sarcopenia in adults and children with ESLD.

Little is known about low-grade astrocytoma with neuraxis dissemination at diagnosis. A review of medical records identified this phenomenon in eight of 150 pediatric patients evaluated between 1985 and 1994 for histologically confirmed low-grade astrocytoma. These patients (five male and three female) ranged in age from 5 months to 20 years (median 8 years). Symptoms of neuraxis disease were minimal or absent. Primary tumor sites were the hypothalamus in four cases, brainstem/spinal cord in three, and temporal lobe in one. Patterns of dissemination (evaluated by computerized tomography and/or magnetic resonance imaging techniques) appeared to be related to the primary site: hypothalamic tumors metastasized along the ventricular cerebrospinal fluid pathways, and tumors in other locations disseminated along subarachnoid pathways. Following initial treatment with chemotherapy (in three), partial resection (in one), radiation therapy (in three), and chemotherapy plus irradiation (in one), four patients required salvage therapy for progressive or recurrent disease. Seven of the eight patients are alive with stable or progressive disease 6 to 105 months postdiagnosis (median 15 months). Low-grade astrocytoma with initial neuraxis dissemination is responsive to chemotherapy and radiation, a proportion showing periods of stable disease. The optimum therapy or combination of therapies remains unclear.

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Observed differences in pharmacokinetics were attributed to body weight, with no additional independent effect of age. Thus, no dose adjustment from the standard dose of gadobutrol in adults based on body weight (0.1 mmol/kg) is necessary in pediatric patients aged 2 to 17 years. Gadobutrol was safe and well tolerated in the pediatric population in this study.

Islet transplantation is an innovative and effective clinical strategy for patients with type 1 diabetes whose clinical condition is inadequately managed even with the most aggressive medical treatment regimens. In islet transplantation, purified islets extracted from the pancreas of deceased donors are infused into the portal vein of the recipient liver. Engrafted islets produce insulin and thus restore euglycemia in many patients. After islet transplantation performed with the original Edmonton protocol, 80% of patients were insulin independent at 1 year and approximately 20% were insulin independent at 5 years. With more recent technical advances, 50% of patients or more maintain insulin independence 5 years after islet transplantation. The success rate with single-donor islet infusions has markedly improved over time. Even in patients who lose insulin independence, islet transplantation is considered successful because it provides improved glycemic control and a higher quality of life. Imaging plays an important role in islet transplantation and is routinely used to evaluate potential recipients, guide the transplantation process, and monitor patients for posttransplantation complications. Because of the success of islet transplantation and its increasing availability worldwide, familiarity with the role of imaging is important.