Intramedullary epidermoid cyst. Contribution of magnetic resonance imaging

Epidermoid tumors are seldom found as a cause of spinal cord compression; still fewer involve the spinal cord itself. We report a case of a thoracic intramedullary epidermoid tumor documented by MRI.     

Classification of patients with a clinically isolated syndrome based on signs and symptoms is supported by magnetic resonance imaging results

BACKGROUND: Recently, a clinical classification system was described to determine whether symptoms and signs of patients presenting with a first episode suggestive of multiple sclerosis (MS) indicate the presence of monofocal or multifocal disease. OBJECTIVES: To evaluate the value of this new classification system by comparing the results with those of simultaneously obtained magnetic resonance imaging (MRI) scans. METHODS: The 487 patients, randomised in the BENEFIT study, were centrally assessed using the new system and classified as monofocal or multifocal, based on clinical information by two neurologists masked for the MRI results. MRI analyses were performed by expert readers masked for the clinical classification. RESULTS: Patients classified as multifocal had more T2 hyperintense (median: 21 versus 15.5) and more T1 hypo-intense lesions (median: 2 versus 1) than those classified as monofocal. Patients classified at the local site as having evidence of a single clinical lesion, but reclassified centrally as having a clinical multifocal central nervous system presentation, had more T2 lesions than monofocal patients. In addition, patients with a multifocal presentation more often fulfilled the MRI criteria for dissemination in space, as incorporated in the International Panel (IP) diagnostic criteria for MS. CONCLUSION: These data provide justification for the recently proposed clinical classification system to be used in patients who present with a first episode suggestive of MS, in that ;multifocal', based on symptoms and signs, is associated with more lesions on MRI.     

Serial magnetic resonance imaging in multiple sclerosis: correlation with attacks, disability, and disease stage

Serial MRI and clinical testing was performed on 45 well-defined untreated multiple sclerosis patients in different categories of disease (relapsing-remitting, progressive, stable). Up to 24 MRIs were scheduled over a 1-year period for each patient. Clinical evaluation was performed monthly and at times of attacks using the Expanded Disability Status Scale (EDSS) and the Ambulation Index (AI). MRI scans were performed both with and without gadolinium enhancement. MRI lesion volume was determined by computerized analysis and gadolinium-enhancing lesions were counted by radiologists. We observed an increase in lesion volume over 1 year in all patient groups except those classified clinically as stable. In relapsing-remitting patients there were correlations between increases in the number of gadolinium enhancing lesions and increases in EDSS and the occurrence of attacks. In chronic progressive patients, increases in lesion volume were correlated with both increases in EDSS and AI. These results demonstrate a linkage between MRI and clinical disease that depends both on the stage of MS and the MRI measures used and support the use of MRI as a surrogate marker of clinical disability in the study of multiple sclerosis.     

Anatomic basis of amygdaloid and hippocampal volume measurement by magnetic resonance imaging.

Both the amygdala and the hippocampus are involved in the pathogenesis of a number of neurologic conditions, including temporal lobe epilepsy, postanoxic amnesia, and Alzheimer's disease. To enhance the investigation and management of patients with these disorders, we developed a protocol to measure the volumes of the amygdala and as much of the hippocampus as possible (approximately 90 to 95%) using high-resolution MRI. We present the anatomic basis of these two protocols and our results in normal control subjects. These volumetric studies of the amygdala may clarify the role of this structure in the pathogenesis of temporal lobe epilepsy.     

胶质母细胞瘤的磁共振征象与免疫组化的关系

目的 研究胶质母细胞瘤(GBM)的磁共振(MRI)征象与异柠檬酸盐脱氢酶(IDH)1、O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)免疫组化的关系.方法 收集2008年1月至2013年12月病理诊断为GBM的病例,分析术前MRI与IDH1、MGMT免疫组化之间的关系.结果 111例患者,术后病理均行IDH1、MGMT免疫组化检查,IDH1阳性29例(26.1％),MGMT阳性60例(54.1％).单因素分析显示,肿瘤最大直径(x2=9.400,P=0.009)、MRI增强(t=2.204,P=0.030)、瘤周水肿(PTE)分度(x2=6.411,P=0.041)和主要侵袭部位(=2.788,P =0.006)与IDH1的阳性表达存在相关性.Logistic多因素回归分析显示,肿瘤最大直径(P=0.015)、MRI增强(P =0.037)和主要侵袭部位(P =0.024)是预测IDH1阳性表达的主要因子,其中肿瘤最大直径是最重要的预测因子(P＜0.05);MGMT的阳性表达与病变个数(x2 =6.678,P=0.010)、磁共振扩散加权成像(DWI)(t=-4.320,P=0.000)、囊变(x2=16.185,P=0.000)、坏死(x2=8.325,P=0.004)和主要侵袭部位(t=2.612,P=0.010)相关.Logistic多因素回归分析显示,病变数量(P =0.008)、囊变(P=0.000)和DWI(P =0.000)是预测MGMT阳性表达的主要因子,其中DWI高信号是最重要的预测因子(P＜0.05).结论 IDH1、MGMT免疫组化结果与常规MRI上肿瘤表现具有一定相关性.通过分析影像和病理的相关性,有利于筛选和初步判断肿瘤的生物学行为和判断其预后.     

Hemifacial spasm: evaluation by magnetic resonance imaging and magnetic resonance tomographic angiography.

We evaluated 37 patients with hemifacial spasm and 16 age-matched control patients with other neurological disorders using magnetic resonance (MR) imaging, MR angiography, and MR tomographic angiography. MR tomographic angiography is a new technique using computer reconstruction of MR angiographic images to create coronal angiotomes that display tissue and arterial structures on the same image. Twenty-four of 37 (64.9%) patients with hemifacial spasm had ipsilateral vascular compression of cranial nerve VII or the pons noted by this technique, whereas only 1 of 16 (6.3%) control patients had compression. MR imaging and MR angiography were less sensitive and less specific in evaluating for vascular compression. This study supports vascular compression of cranial nerve VII or the pons as a cause of hemifacial spasm, and demonstrates MR tomographic angiography's value as an excellent, noninvasive technique to demonstrate the compression.     

Axial signs and magnetic resonance imaging correlates in Parkinson's disease

BACKGROUND: Age-related brain changes may contribute to axial features in Parkinson's disease (PD). OBJECTIVES: To determine if ventricular volume and white matter high signal changes (WMC) are related to motor signs in PD and controls independent of age. METHODS: Patients were rated with the Unified Parkinson's Disease Rating Scale (subscore A: tremor, rigidity, bradykinesia, and facial expression; subscore B: speech and axial impairment). Steps and time taken to walk 9.144 meters were measured. Total ventricular volume (TVV) and intracranial volume (ICV) were measured on T1-weighted MRI using manual tracing software. WMC were rated on axial T2-weighted, dual-echo or FLAIR MR images using a visual scale. RESULTS: TVV (cm3) (PD: 36.48 +/- 15.93; controls: 32.16 +/- 14.20, p = 0.21) and WMC did not differ between groups (PD: 3.7 +/- 4.2; controls: 3.2 +/- 3.1, p = 0.55). Age correlated positively with ICV-corrected TVV and WMC in PD (cTVV: r = 0.48, p = 0.003; WMC: r = 0.42, p = 0.01) and controls (cTVV: r = 0.31, p = 0.04; WMC: r = 0.44, p = 0.003). Subscore B (r = 0.42, p = 0.01) but not subscore A (r = 0.25, p = 0.14) correlated with cTVV in PD. Steps and walking time correlated with cTVV and WMC in PD; cadence correlated with cTVV and steps with WMC in controls. Age-adjustment eliminated correlations. CONCLUSION: Subscore B, but not subscore A correlated positively with ventricular volume in PD, though this association was accounted for by age. Age-related brain change super-imposed on PD may contribute to axial features.     

Globoid cell leukodystrophy: comparison of neuropathology with magnetic resonance imaging

Previous imaging studies in infants with globoid cell leukodystrophy (GLD) using computed tomography have demonstrated a reduction in cerebral white matter and increased density symmetrically in the regions of the thalami, periventricular white matter, and the internal capsules. Correlation of these findings with morphologic studies at necropsy has not been made. In particular, deposition of calcium has not been described. We have evaluated two children with GLD confirmed by the absence of leukocyte galactosylceramide -galactosidase activity using repeated magnetic resonance (MR) scans in each and correlated the imaging results with post-mortem analyses in one. Neuropathologic examination revealed abnormalities typical for GLD. In addition to the absence of normal myelination throughout cerebral and cerebellar white matter, MR images demonstrated the presence of a paramagnetic effect in the regions of the thalami, corona radiata, and centra semiovale. We have observed in histologic preparations from these areas a dense accumulation of globoid cells and some calcium, which we suggest may be responsible for producing the paramagnetic effect.Supported in part by funds from the Texas Children's Hospital     

Pyramidal tract mapping by diffusion tensor magnetic resonance imaging in multiple sclerosis: improving correlations with disability

BACKGROUND: Current magnetic resonance imaging (MRI) outcome measures such as T2 lesion load correlate poorly with disability in multiple sclerosis. Diffusion tensor imaging (DTI) of the brain can provide unique information regarding the orientation and integrity of white matter tracts in vivo. OBJECTIVE: To use this information to map the pyramidal tracts of patients with multiple sclerosis, investigate the relation between burden of disease in the tracts and disability, and compare this with more global magnetic resonance estimates of disease burden. METHODS: 25 patients with relapsing-remitting multiple sclerosis and 17 healthy volunteers were studied with DTI. An algorithm was used that automatically produced anatomically plausible maps of white matter tracts. The integrity of the pyramidal tracts was assessed using relative anisotropy and a novel measure (L(t)) derived from the compounded relative anisotropy along the tracts. The methods were compared with both traditional and more recent techniques for measuring disease burden in multiple sclerosis (T2 lesion load and "whole brain" diffusion histograms). RESULTS: Relative anisotropy and L(t) were significantly lower in patients than controls (p < 0.05). Pyramidal tract L(t) in the patients correlated significantly with both expanded disability status scale (r = -0.48, p < 0.05), and to a greater degree, the pyramidal Kurtzke functional system score (KFS-p) (r = -0.75, p < 0.0001). T2 lesion load and diffusion histogram parameters did not correlate with disability. CONCLUSIONS: Tract mapping using DTI is feasible and may increase the specificity of MRI in multiple sclerosis by matching appropriate tracts with specific clinical scoring systems. These techniques may be applicable to a wide range of neurological conditions.     

Temporal lobe measurement in primary affective disorder by magnetic resonance imaging

Magnetic resonance imaging brain scans were performed on 17 patients with primary affective disorder and 21 normal subjects. A coronal slice through the temporal lobes at the level of the pons and interpeduncular cistern was selected in each subject, and specific temporal lobe structures and the cerebral area were measured. Ratios between structures of the same hemisphere were calculated. The ratio of the temporal lobe to cerebral area was smaller in patients than controls both on the left (p less than .02) and on the right (p less than .03). The data suggest that patients with primary affective disorder may have a relative decrease in the size of the temporal lobe compared with normal controls.     

Quantitative diffusion weighted magnetic resonance imaging, cerebral atrophy, and disability in multiple sclerosis

OBJECTIVES: To investigate the relations between quantitative diffusion coefficient MRI histograms, clinical variables, and cerebral atrophy. METHODS: Twenty two patients with clinically definite multiple sclerosis and 11 healthy volunteers were studied. Histograms of apparent diffusion coefficient (ADC) from a volume of interest that included multiple slices encompassing the lateral ventricles were processed from diffusion weighted MRI. In addition, total lesion load was measured on T2 weighted dual echo images, and cerebral volume from 3D magnetisation prepared rapid acquisition gradient echo scans. All patients underwent neurological assessment, including disability on the expanded disability status scale (EDSS). RESULTS: Histograms from the patient group showed a reduced peak height and a "right shift" compared with healthy controls. Peak height of the diffusion histogram correlated with both EDSS (r=-0.54, p=0.0101) and disease duration (r=-0.52, p=0.0140), but not with age. Brain volume correlated with peak height of the ADC histogram (r=0.55, p=0.0129), but not with disability. Total lesion load also correlated moderately with EDSS (r=0.46, p=0.03). CONCLUSIONS: This study shows for the first time that quantitative MRI measures of diffusion correlate with clinical variables (disability, disease duration) and cerebral atrophy in multiple sclerosis. Cerebral atrophy and fixed neurological deficit may be attributed to axonal loss, which would be expected to have a significant effect on ADC. Extension of this method to more patients and longitudinal studies will further elucidate its sensitivity, reproducibility, and potential role in clinical practice and treatment trials.     

Cerebellar infarction: comparison of computed tomography and magnetic resonance imaging

We correlated clinical, computed tomographic (CT), and magnetic resonance imaging (MRI) findings in 14 patients with cerebellar infarctions. Before MRI, the diagnosis of cerebellar infarction was made in only 7 patients on the basis of clinical and CT evidence. Cerebellar infarction was bilateral in 3 patients and was associated with brainstem infarction in 6. Infarction occurred in the territory of the posterior inferior cerebellar artery (PICA) in 12 patients. The territory of the superior cerebellar artery (SCA) was involved in 1 patient, and 1 infarction encompassed the watershed between the PICA and the SCA. In patients with infarction of the PICA territory, the medial and intermediate hemispheric segments were most frequently involved. Involvement of the lateral hemispheric segment was infrequent and was independent of brainstem involvement. Because of its fine demonstration of anatomical detail, its lack of bony artifact, and its ability to visualize infarctions readily within the first 24 hours, MRI is an excellent method for demonstrating cerebellar infarction.     

Relationship between levodopa-independent symptoms and central atrophy evaluated by magnetic resonance imaging in Parkinson's disease.

Thirty patients with Parkinson's disease were studied for the purpose of investigation relations between motor symptoms and cerebral atrophy evaluated by magnetic resonance imaging (MRI). Axial symptoms (gait disorder, postural instability and difficulty in arising from a chair), assessed at the time of maximum clinical improvement, were significantly correlated with frontal atrophy, while no correlation was found between the basal parkinsonian disability score and cerebral atrophy. It is suggested that frontal atrophy observed by MRI is linked with axial motor symptoms resulting from non-dopaminergic lesions. The origin of this atrophy is unknown.     

Axonal loss in multiple sclerosis lesions: magnetic resonance imaging insights into substrates of disability.

Magnetic resonance imaging (MRI) monitoring of disease progression in multiple sclerosis is limited by the lack of correlation of abnormalities seen on T2-weighted imaging, and disability. We studied the histopathology of multiple sclerosis lesions, as depicted by MRI, in a large postmortem sample, focusing on axonal loss. Tissue samples from 17 patients were selected immediately postmortem for histopathological analysis on the basis of T2-weighted imaging, including normal appearing white matter and T1 hypointense lesions. In each region, we measured magnetization transfer ratios (MTR), T1 contrast ratio, myelin, and axonal density. T2 lesions (109 samples) were heterogeneous with regard to MRI appearance on T1 and MTR, whereas axonal density ranged from 0% (no residual axons) to 100% (normal axonal density). Of 64 T2 lesions, 17 were reactive (mild perivascular inflammation only), 21 active, 15 chronically active, and 11 chronically inactive. MTR and T1 contrast ratio correlated strongly with axonal density. Also in normal appearing white matter (24 samples), MTR correlated with axonal density. In conclusion, postmortem tissue sampling by using MRI revealed a range of pathology, illustrating the high sensitivity and low specificity of T2-weighted imaging. T1 hypointensity and MTR were strongly associated with axonal density, emphasizing their role in monitoring progression in multiple sclerosis.     

Correlation of magnetic resonance imaging parameters with clinical disability in multiple sclerosis: a preliminary study

Magnetic resonance imaging (MRI) is frequently used to monitor new treatments in multiple sclerosis (MS), but its role is limited by the uncertain relationship between MRI parameters and clinical disability. A brain MRI study using nine MRI parameters was undertaken in 15 MS patients with a wide spectrum of disability to evaluate the relationship between each parameter and disability. A strong correlation was found between disability (measured using Kurtzke’s EDSS) and total lesion load on both proton density (PD; r = 0.79) and T1 (r = 0.71) weighted sequences. There was also a strong correlation of disability with average lesion magnetisation transfer ratio (MTR; r = –0.74) and calculated T1 (r = 0.71) but not with calculated T2 or the average signal intensity of lesions on the conventional T1-weighted, PD-weighted and heavily T2-weighted images. Thus, four parameters which measured either the extent of lesions (PD lesion load) or their pathological severity (MTR, calculated T1, hypointense T1-lesion load) were correlated significantly with disability. While this suggests that such parameters will be useful in treatment trial monitoring, further multi-parameter MRI studies, of larger cohorts and using a wider range of techniques, are indicated. Received: 29 August 1998 Received in revised form: 29 April 1999 Accepted: 5 May 1999     

Diffusion-weighted magnetic resonance imaging.

Diffusion-weighted magnetic resonance imaging is a specialized technique that measures the degree of diffusion of water molecules within extracellular space and between intracellular and extracellular space. Diffusion-weighted imaging signal is high (bright) when diffusion is restricted, as occurs in cytotoxic damage from ischemia, inflammation, trauma, or tumor. This technique, now available on most magnetic resonance imaging units, is especially helpful in detecting early ischemic stroke and multiple sclerosis and in differentiating arachnoid cyst from epidermoid tumor and brain abscess from neoplasm.     

Clinical and magnetic resonance imaging study of extrapyramidal symptoms in multiple system atrophy.

Slit-hyperintensity in the outer margin of the putamen on T2 weighted MRI was found in 17 out of 28 patients with clinically diagnosed multiple system atrophy. Thirteen of these 17 patients showed extrapyramidal signs. Five patients had only unilateral slit-hyperintensity; four of them had contralateral rigidity; and one had bradykinesia. Despite mild rigidity, one case showed no slit-hyperintensity. One of the 14 cases with parkinsonism showed no hyperintensity, and four of the 14 cases without parkinsonism showed hyperintensity. On the other hand, slit-hyperintensity was not seen in any of 25 patients with clinically diagnosed Parkinson's disease. Putaminal slit-hyperintensity is a useful MRI feature in the differential diagnosis between Parkinson's disease and multiple system atrophy predominantly affecting the extrapyramidal system.