MDCT diagnosis of ileocolic intussusception secondary to an appendiceal mucocele: value of multiplanar reformation

We describe an extremely rare case of an ileocolic intussusception with an appendiceal mucocele as the lead-point and cause of acute right lower quadrant pain in an adult patient. There are only few reported cases of this entity in the radiologic literature. We describe the multislice (computed tomography) CT features and emphasize the value of multiplanar reformations. We also discuss how specific findings on CT should allow for a correct preoperative diagnosis. This case report has not been presented previously at any Radiology meeting. No grants were received for this case report. The authors disclose no potential conflict of interest.     

Image content extraction: application to MR images of the brain.

A system for automatically extracting image content features was developed that combines registration to a labeled atlas with natural language processing of free-text radiology reports. The system was then tested with T1-weighted, spoiled gradient-echo magnetic resonance (MR) imaging studies of the brain performed in nine patients. The locations of 599 structures were visually assessed by an experienced radiologist and compared with the locations indicated by automated output. The in-plane accuracy of the contours was subjectively evaluated as either good, moderate, or poor. The criterion for classifying a structure as correctly located was that 90% or more of all the images containing the structure had to be correctly identified. For 98% of the structures, the images identified by the automated algorithm agreed with those identified by the radiologist, and in 83% of cases, image contours showed a good in-plane overlap. The results of this validation study demonstrate that this combination of registration and natural language processing is accurate in identifying relevant images from brain MR imaging studies. However, the range of applicability of this technique has yet to be determined by applying the technique to a large number of studies.     

Progressive cerebral edema associated with high methionine levels and betaine therapy in a patient with cystathionine β‐synthase (CBS) deficiency

Cystathionine β‐synthase (CBS) deficiency, the most common form of homocystinuria, is an autosomal recessive inborn error of homocysteine metabolism. Treatment of B6‐nonresponsive patients centers on lowering homocysteine and its disulfide derivatives (tHcy) by adherence to a methionine‐restricted diet. However, lifelong dietary control is difficult. Betaine supplementation is used extensively in CBS‐deficient patients to lower plasma tHcy. With betaine therapy, methionine levels increase over baseline, but usually remain below 1,500 μmol/L, and these levels have not been associated with adverse affects. We report a child with B6‐nonresponsive CBS deficiency and dietary noncompliance whose methionine levels reached 3,000 μmol/L on betaine, and who subsequently developed massive cerebral edema without evidence of thrombosis. We investigated the etiology by determining methionine and betaine metabolites in our patient, and several possible mechanisms for her unusual response to betaine are discussed. We conclude that the cerebral edema was most likely precipitated by the betaine therapy, although the exact mechanism is uncertain. This case cautions physicians to monitor methionine levels in CBS‐deficient patients on betaine and to consider betaine as an adjunct, not an alternative, to dietary control. © 2002 Wiley‐Liss, Inc.     

Monte Carlo模拟法评估多层螺旋CT扫描时胎儿所受剂量与孕妇体型及孕龄关系

目的利用Monte Carlo模拟法对不同胎龄及不同母体体型的孕妇进行腹部或盆腔检查时胎儿所接受的辐射剂量。材料与方法本研究得到了临床试验机构伦理委员     

Traumatically induced reactive change as visualized through the use of monoclonal antibodies targeted to neurofilament subunits.

Reactive axonal change has long been recognized as a feature of traumatic brain injury. To date, the histological methods used to identify reactive axons have been of limited utility, and they have not provided insight into the initial intraaxonal event that triggers reactive change. In this investigation, monoclonal antibodies to the 68, 150, and 200 kilodalton (kD) neurofilament subunits have been used to follow the progression of reactive axonal change. Anesthetized rats and cats were subjected to moderate traumatic brain injury. One to 72 hours (h) postinjury, their brains were processed for the light (LM) and electron (EM) microscopic immunocytochemical visualization of the various neurofilament subunits. Although all of the chosen antibodies revealed some degree of immunoreactivity within the reactive axon, the 68 kD antibody revealed a dramatic increase in immunoreactivity following injury. Within one h of injury, intensely 68 kD-immunoreactive axonal segments were observed with LM, and parallel EM microscopic analyses demonstrated that this increased immunoreactivity was associated with an increased number of 68 kD-immunoreactive neurofilaments, the majority of which coursed in an axis parallel to the axon's course. Over 2-6 h postinjury, these 68 kD-immunoreactive filaments demonstrated increasingly disordered alignment in relation to the axon's long axis, withdrawing from the focus of injury while becoming encompassed by an expanding organelle cap. It is posited that this increased 68 kD immunoreactivity is associated with a traumatically-induced increase in subunit exchange which contributes to cytoskeletal dysfunction leading to organelle accumulation, focal swelling and ultimate axonal detachment.     

Massive subperiosteal hemorrhage in neurofibromatosis.

Neurofibromatosis is seen in association with elephantiasis neuromatosa and overgrowth of abnormal bones, but rarely with subperiosteal hemorrhage.This is a secondary finding after severe or minor trauma to the periosteum, which is abnormally loose from mesodermal dysplasia. The clinical, plain radiographic, and angiographic findings of 2 cases of massive subperiosteal hemorrhage are presented, and the literature reviewed.