Incidence of focal white matter lesions in a population of hemophiliac children and their normal siblings. Hemophilia Growth and Development Study.

OBJECTIVE: This analysis was undertaken to evaluate the etiology and sequelae of 2- to 5-mm focal white matter hyperintensities on T2-weighted MR images of some participants enrolled in the Hemophilia Growth and Development Study (HGDS). MATERIALS AND METHODS: The HGDS is a multicenter study of the growth and development, neurological, neuropsychological, and immune functioning of a cohort of children and adolescents, 62% of whom were infected with HIV through the use of clotting factor concentrates, and their non-hemophiliac, non-HIV infected male siblings. The current investigation was conducted with all three groups of HGDS participants: HIV-positive hemophiliacs (n = 207), HIV-negative hemophiliacs (n = 126), and their siblings (n = 47). Magnetic resonance imaging was performed at each center, with a variety of 0.3 to 1.5 T instruments. Standard examinations included 5-mm-thick T1-weighted sagittal and axial images, intermediate, and T2-weighted axial images. A study of abnormalities of the coagulation system known to be associated with thrombotic events was conducted among a subgroup of participants (n = 51) from eight centers. RESULTS: Lesions were not associated with hemophilia-related factors, immune function, hematologic, or neurologic factors. There were no associations between the presence of white matter lesions and defects of coagulation in any of the assays completed. CONCLUSION: The 2- to 5-mm focal white matter hyperintensities on T2-weighted MR images of the brain were incidental findings in our study population.

Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations.

BACKGROUND: There is no agreement regarding the preoperative measurement of liver volumes and the minimal safe size of the liver remnant after extended hepatectomy. METHODS: In 20 patients with hepatobiliary malignancy and no underlying chronic liver disease, volumetric measurements of the liver remnant (segments 2 and 3 +/- 1) were obtained before extended right lobectomy (right trisegmentectomy). The ratios of future liver remnant to total liver volume were calculated by using a formula based on body surface area. In 12 patients, response to preoperative right trisectoral portal vein embolization was evaluated. In 15 patients who underwent the planned resection, preoperative volumes were correlated with biochemical and clinical outcome parameters. RESULTS: The future liver remnants increased after portal vein embolization (26% versus 36%, P < .01). Smaller size liver remnants were associated with an increase in postoperative liver function tests (P < .05) and longer lengths of hospital stay (P < .02). Preliminary data indicates an increase in major complications for liver volumes < or = 25% (P = .02). CONCLUSIONS: A simple method of measurement provides an assessment of the liver remnant before resection. It is useful in evaluating response to portal vein embolization and in predicating the outcome before extended liver resections.

Prevalence and incidence of intracranial haemorrhage in a population of children with haemophilia. The Hemophilia Growth and Development Study.

The prevalence of intracranial haemorrhage (ICH) in our population of haemophiliacs was 12%. The incidence of ICH was approximately 2% per year. At entry, 7% (21/309) had clinical histories of ICH without MRI evidence of old haemorrhage, indicating that either the haemorrhages had completely resolved, that routine MRI sequences are not particularly sensitive for the detection of old blood products, or a combination of both of these factors. One half (4/8) of the ICHs documented by entry MRI were clinically silent, and three of the 11 incident cases documented by MRI were clinically silent. HIV infection did not increase the risk of ICH.

MRI of primary lymphoma of bone: cortical disorder as a criterion for differential diagnosis.

To investigate the pattern and dimension of cortical bone abnormality on magnetic resonance imaging (MRI) as a feature to distinguish primary lymphoma of bone from osteosarcoma and Ewing sarcoma, 46 patients with primary malignant bone lesions with a soft tissue mass (16 osteosarcomas, 15 Ewing sarcomas, 15 lymphomas) were examined with MRI (T1-weighted pre-/postcontrast spin-echo sequences and T2-weighted spin-echo and fast spin-echo sequences; 1.5 T system). Qualitative image analysis revealed no differences for signal characteristics and enhancement. Lymphomas appeared significantly more often homogeneous (47%; Ewing sarcoma 20%; osteosarcoma 6%/o), and patients were significantly older (cutoff point 30 years). Lymphomas showed significantly less frequent cortical abnormality (60%; Ewing sarcoma 87%; osteosarcoma 100%), complete penetration (13%; Ewing sarcoma 67%; osteosarcoma 87%), focal destruction (13%; Ewing sarcoma 40%; osteosarcoma 81%), and complete destruction (0%; Ewing sarcoma 13%; osteosarcoma 19%). In conclusion, primary lymphoma of bone is characterized by minimal cortical changes despite an accompanying soft tissue mass in a patient over 30 years of age.

Brachial plexus: demonstration at US.

Five healthy volunteers underwent ultrasonography (US) to determine the feasibility of visualizing the brachial plexus. The roots, trunks, and cords could be identified in the supraclavicular and infraclavicular regions. The roots within the neural foramina and the epidural space could not be evaluated. US may play a complementary role in the evaluation of patients with brachial plexopathy.

Effects of human immunodeficiency virus and immune status on magnetic resonance imaging of the brain in hemophilic subjects: results from the hemophilia growth and development study.

To determine the effects of hemophilia and human immunodeficiency virus (HIV) infection on the nervous system, the authors examined the relationship of brain magnetic resonance imaging (MRI) findings to immunologic function and neurologic examination findings. Baseline examinations included physical and neurologic examination, immunologic and virologic testing, and MRI of the brain. On neurologic examination, muscle atrophy was considered to be related to hemophilia if adjacent joints had arthropathy due to bleeding. Muscle atrophy was considered non-hemophilia-related if unrelated to arthropathy or if muscle atrophy was diffuse. Subjects were boys aged 6 to 19 years, enrolled in a multicenter study of the effects of hemophilia and HIV infection on growth and development, all with congenital coagulopathies requiring factor infusions. Three hundred ten subjects had complete data including neurologic examination, T-cell subsets, HIV antibodies, and MRI. Subjects with HIV infection whose CD4+ counts were < 200/microL were compared with subjects with HIV infection and CD4+ counts > or = 200/microL and with HIV-negative subjects, all of whom had CD4+ counts > 200/microL. MRI studies were normal in 230. Abnormal MRI studies were more frequent in HIV-positive subjects with CD4+ counts < 200 (29.4% abnormal compared with 17% in HIV-positive subjects with CD4+ counts > or = 200 and 15.3% in HIV-negative subjects). Diffuse atrophy accounted for most of the excess abnormalities in HIV-positive subjects with CD4+ counts < 200 (77.3% of abnormal scans). Diffuse atrophy on MRI was associated with decreased muscle bulk on neurologic examination, but not with abnormal tendon reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain abnormalities in male children and adolescents with hemophilia: detection with MR imaging. The Hemophilia Growth and Development Study Group.

Cranial magnetic resonance (MR) imaging was performed in 124 male patients (aged 7-19 years), from 14 institutions, in whom a diagnosis of moderate to severe hemophilia was made. Blood tests in all subjects were negative for human immunodeficiency virus. Findings in MR studies were abnormal in 25 (20.2%) subjects. Six lesions in five subjects were classified as congenital. The most commonly identified congenital lesion was a posterior fossa collection of cerebrospinal fluid (five cases). Twenty-two subjects had acquired lesions that were probably related to the hemophilia or its treatment. The most commonly acquired lesions were single- or multifocal areas of high signal intensity within the white matter on T2-weighted images noted in 14 (11.3%) subjects. Two subjects had large focal areas of brain atrophy, and six had some degree of diffuse cerebral cortical atrophy. Three subjects (2.4%) had hemorrhagic lesions. To the authors' knowledge, the unexpected finding of small, focal, nonhemorrhagic white matter lesions has not previously been reported.

Subdural hygroma versus atrophy on MR brain scans: "the cortical vein sign".

PURPOSE: To determine if the position of the superficial cerebral cortical veins can be used to distinguish subdural hygroma from atrophy on MR brain scans. METHODS: Retrospective review of MR scans obtained in cases of extracerebral fluid collections, separating these into two groups, ie, subdural hygroma or atrophy. FINDINGS: All cases of atrophy in this study showed cortical veins and their branches traversing widened cerebrospinal fluid spaces over the cerebral convexities. None of the subdural hygroma patients showed this finding. Cortical veins in hygroma patients were seen only at the margin of the displaced cortex, and did not traverse the fluid collections over the cerebral convexities. CONCLUSIONS: The authors call the visualization of cortical veins and their branches within fluid collections at the cerebral convexities "the cortical vein sign." They believe this sign to be prima facie evidence of atrophy; its presence rules out the diagnosis of subdural hygroma in the region of interest.

Bilateral neonatal Sturge-Weber-Dimitri disease: CT and MR findings.

The CT and MR features of cortical calcification and meningeal angiomatosis are typical of Sturge-Weber-Dimitri disease but are unusual in children less than 1 year of age. This case describes a child presenting with both of these features bilaterally in the neonatal period and represents an unusual presentation of this disorder.

Proton magnetic resonance of exercise-induced water changes in gastrocnemius muscle.

Exercise-induced water concentration changes have been determined in the medial gastrocnemius muscle noninvasively with image-guided in vivo proton magnetic resonance spectroscopy (MRS). These measurements were performed on seven normal male volunteers during and after isometric and ischemic-isometric exercise at 5, 10, and 20% maximum voluntary contraction (MVC). The observed water flux changes during different phases of exercise have been interpreted in terms of fluid transfer between the vasculature and exercising muscle. Good correlation between individual MVC and changes in water fluxes and the decay of water content was observed after 20% MVC exercise level. MRS results have been found to be consistent with those reported in the literature based on invasive biopsy techniques.

Proton magnetic resonance spectroscopy in multiple sclerosis.

Regional in vivo proton magnetic resonance spectroscopy provides quantitative data on selected chemical constituents of brain. We imaged 16 volunteers with clinically definite multiple sclerosis on a 1.5 tesla magnetic resonance scanner to define plaque-containing volumes of interest, and obtained localized water-suppressed proton spectra using a stimulated echo sequence. Twenty-five of 40 plaque-containing regions provided spectra of adequate quality. Of these, 8 spectra from 6 subjects were consistent with the presence of cholesterol or fatty acids; the remainder were similar to those obtained from white matter of normal volunteers. This early experience with regional proton spectroscopy suggests that individual plaques are distinct. These differences likely reflect dynamic stages of the evolution of the demyelinative process not previously accessible to in vivo investigation.

Serial proton magnetic resonance spectroscopy of ischemic brain injury in humans.

Four patients were observed serially with 1H magnetic resonance spectroscopy (MRS) at times ranging from 3 days to 10 weeks after a documented ischemic event. Spectra were obtained from 8 cc volumes in infarcted regions and contralateral matched normal regions. Reproducible variations in n-acetyl aspartate (NAA), creatine + phosphocreatine (Cr + PCr), and the sequential changes in lactate and lipid resonances are related to the pathophysiology of stroke. A conspicuous lack of significant change in the choline (Cho) resonance with concomitant decrease in NAA and Cr + PCr is reported as a possible marker of ischemic injury.