Infratentorial hypointense lesion volume on T1-weighted magnetic resonance imaging correlates with disability in patients with chronic cerebellar ataxia due to multiple sclerosis.

In multiple sclerosis (MS), hypointense lesions on T1-weighted magnetic resonance imaging are thought to represent areas of tissue disruption and axonal loss. In previous studies of MS patients, infratentorial T1 hypointense lesions were found to be rare. In MS patients selected to have chronic cerebellar ataxia, we have determined the extent of infratentorial T1 hypointense lesions and their relationship with disability. We recruited nine patients with chronic cerebellar ataxia due to MS. An expanded disability status scale (EDSS) assessment was performed on each. The patients' brains were then imaged with axial-oblique dual-echo fast spin-echo and contrast-enhanced T1-weighted conventional spin-echo sequences. The number and total volume of infratentorial high-signal lesions on T2-weighted images and infratentorial hypointense lesions on T1-weighted images were calculated by a blinded observer using a computer-assisted contouring technique. A total of 96 infratentorial high-signal lesions were present, of which 62 (64.6%) appeared isointense and 34 (35.4%) hypointense with respect to the surrounding brain substance on the T1-weighted images. There was a median of 3 (range 0-10) and median volume of 0.43 ml (range 0-0.85 ml) infratentorial T1 hypointense lesions per patient. The EDSS score correlated with both the number (r=0.68, p=0.043) and the volume per patient (r=0.89, p=0.001) of infratentorial T1 hypointense but not T2 high-signal lesions. Infratentorial T1 hypointense lesions are often seen in patients with MS and chronic cerebellar ataxia. They may play a significant role in the disability suffered by these patients.     

Significance of the T2*-weighted gradient echo brain imaging in patients with infective endocarditis

Background

Although aneurysm formation accompanying parenchymal hemorrhage is one of devastating complications in the central nerves system (CNS), imaging studies of the brain are not routinely warranted in patients with infective endocarditis (IE). To assess the clinical importance for detecting silent lesions in the central nervous system, we investigated hypointense signal spots detected on the brain T2*-weighted MR imaging in patients with IE.

Methods and results

Eleven patients with IE were retrospectively reviewed. Seven patients (63.6%) showed hypointense signal spots on T2*-weighted MR images. The number of hypointense signal spots increased within only a few weeks in five patients.

Conclusion

The brain T2*-weighted MR imaging in patients with IE may have a potential role to detect CNS lesions with clinical significance of potentially high risk of intracranial hemorrhage. T2*-weighted hypointense signal spots may be specific to brain involvement, and be quite useful in monitoring CNS lesions associated with IE, even if they are asymptomatic.     

Lesion distribution in children with clinically isolated syndromes

We evaluated the incidence, volume, and spatial distribution of T2-weighted magnetic resonance imaging lesions in 58 children with clinically isolated syndromes at risk for multiple sclerosis compared with 58 adults with relapsing-remitting multiple sclerosis. Pediatric patients with clinically isolated syndromes who had brain lesions had supratentorial lesion volumes similar to adult multiple sclerosis patients, but greater infratentorial lesion volumes (p < 0.009), particularly in the pons of male patients. The predilection for infratentorial lesions the pediatric patients with clinically isolated syndromes may reflect immunological differences or differences in myelin, possibly related to the caudorostral temporal gradient in myelin maturation.     

Chagasic Granulomatous Encephalitis in Immunosuppressed Patients; Computed Tomography and Magnetic Resonance Imaging Findings

American trypanosomiasis (Chagas' disease), a zoonosis caused by Trypanosoma cruzi with a high incidence in Latin America, may induce an uncommon form of localized encephalitis termed “chagoma,” found in few immunocompromised patients. The computed tomography (CT) and magnetic resonance imaging (MRI) findings of brain chagoma are reported for 3 males (ages 32, 32, and 9 yr), the first 2 infected with human immunodeficiency virus (HIV) and the third with acute lymphoblastic leukemia. Diagnosis was confirmed by biopsy. CT disclosed a single, supratentorial, nodular-shaped lesion that substantially enhanced with contrast material, localized in parietal or frontal lobes. T1-weighted MRI showed hypointense lesions that enhanced with gadolinium-diethylenetriaminepentaacetic acid, corresponding to extensive hyperintense areas on T2-weighted images, producing mass effect. The imaging pattern of brain chagoma presented here is similar to that of cerebral toxoplasmosis and should be considered in the differential diagnosis of an intracerebral mass lesion in immunocompromised patients.     

Brain CT and MRI Findings in 100 Consecutive Patients with Intracranial Tuberculoma

OBJECTIVE: The characteristics of intracranial tuberculoma on computed tomography (CT) and magnetic resonance imaging (MRI) are not well known. The authors reviewed the features of tuberculoma on CT scans and MRI. The authors also correlated the MRI characteristics on various pulse sequences with neuropathological findings. METHODS: The charts of patients with intracranial tuberculoma were consecutively reviewed during the period from 1988 to 1999. The diagnosis of tuberculoma was based on pathology (n = 19), clinical or neuroimaging response to tuberculous chemotherapy (n = 57), or evidence of systemic tuberculosis (n = 24). Neuropathological specimens of tuberculoma were graded for the amount of fibrosis, gliosis, necrosis, and cell types (lymphocytes, macrophages, plasma cells). RESULTS: One hundred patients (43 men) were identified. The age range was 1 to 75 years (mean = 30 y). The number of lesions ranged from 1 to > 100 (mean = 4.5 lesions/patient). Thirty-one patients had solitary lesions, whereas 69 had multiple lesions. Thirty-seven patients had hydrocephalus. After contrast administration, > 450 lesions were seen on CT and MRI images in all 100 scans. The diameter of these enhancing lesions ranged from 1 mm to 5 cm. Lesions > 1 cm showed varied enhancement, including irregular shapes, ringlike shapes, open rings, and lobular patterns. Targetlike lesions were seen in only 2 patients. Other features included cortical and subcortical infarcts (12 patients), calcification (10% of lesions), edema (33 patients), meningeal enhancement (12 patients), mass effect, and/or midline shift (18 patients). A hypointense core with a hyperintense rim was the most common signal characteristic on T2-weighted MRI. The central hypointensity on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images reflected extensive necrosis and hypercellularity. CONCLUSION: Multiple tuberculomas and infratentorial locations were more common in the authors' patient population than in previous reports. The MRI signal characteristics of intracranial tuberculoma are extremely diverse. An isointense or hypointense core with a hyperintense rim on T2-weighted and FLAIR images is the most common presentation. Core hypointensity of lesions on these images is related to necrosis and the large number of cells.     

Proton Magnetic Resonance Spectroscopy and Magnetic Resonance Imaging Findings in a Patient with Central Nervous System Paracoccidioidomycosis

The authors describe a patient with brain paracoccidioidomycosis whose magnetic resonance image (MRI) showed multiple hypointense lesions on T2-weighted images with peripheral enhancement after gadolinium injection. Single-voxel proton magnetic resonance spectroscopy (1H-MRS) of one of the lesions showed 2 peaks at 0.9 and 1.32 ppm, corresponding to lipid signals, indicating intense necrosis. The other characteristic peaks of 1H-MRS were undifferentiated from baseline. These findings, although not specific, may help to differentiate fungal abscess from tumoral lesions and other types of abscess.     

Technical note: the comparison of hypointense lesions from 'pseudo-T1' and T1-weighted images in secondary progressive multiple sclerosis

There is a large historical database of dual-echo conventional spin-echo (CSE) magnetic resonance images in multiple sderosis (MS). If new analysis techniques can be developed then this database could provide valuable information. We have investigated a technique in which the late echo of a dual-echo data set is subtracted from the corresponding early echoyielding images, which appear qualitatively similar to T1-weighted images. This study investigated whether the hypointense lesions on the 'pseudo-T1' images (created as described above) were related to hypointense lesions on conventional T1-weighted images. The hypointense lesion areas were measured by a blinded observer using a computer-assisted contouring technique applied to pseudo-T1 and T1-weighted CSE images obtained from 17 patients with secondary progressive MS (SPMS). The mean hypointense lesion area from T1-weighted images was 2218 +/- 2072 mm2, compared to 1426 +/- 1353 mm2 from pseudo-T1 images (p = 0.008). There was, however, a strong correlation between the values obtained from the two sets of images (r = 0.93, p < 0.001). The strong correlation between the values obtained from the two sets of images suggests that pseudo-T1 images may be useful to investigate a subgroup of more destructive lesions in MS from historical databases and in future prospective studies when imaging time is limited.     

Miliary tuberculomas of the brain: case report

Tuberculosis (TB) of the central nervous system (CNS) is still prevalent in many developing countries. Tuberculoma is always considered in the differential diagnosis of enhancing intra-axial lesions of the brain. Brain tuberculomas can present in many different clinical and radiological patterns, disseminated or miliary brain tuberculomas are very rare. We describe the case of a 25-year-old immunocompetent female with miliary brain tuberculomas. She presented with a history of progressive headache and unsteady gait. Serial Magnetic resonance imaging (MRI) studies revealed growing, multiple small enhancing lesions in the brain, most lesions measured approximately 2mm in diameter, in both the supratentorial and infratentorial compartments. Her investigation failed to reveal any evidence of TB outside the CNS. Open biopsy revealed multiple caseating granulomas and mycobacterin tuberculosis was cultured. She improved clinically and radiologically after starting anti-tuberculous pharmacotherapy. The clinical course, radiological images and pathological studies of this patient are presented. In conclusion miliary brain tuberculomas are rare and unique clinical and radiological entity. It may affect immunocompetent individuals with no other signs of other systemic involvement.     

Infratentorial lesions predict long-term disability in patients with initial findings suggestive of multiple sclerosis

BACKGROUND: The number and volume of abnormalities on baseline brain magnetic resonance images in patients with initial findings suggestive of multiple sclerosis are known to predict outcome in terms of disability. However, no long-term data exist on specific locations or types of lesions. OBJECTIVE: To assess the long-term predictive value of baseline magnetic resonance imaging parameters, including location of lesions and gadolinium-enhancing and hypointense lesions in patients with initial findings suggestive of multiple sclerosis for the occurrence of clinically relevant disability as defined by an Expanded Disability Status Scale score of 3. PATIENTS: After a median follow-up period of 8.7 years, the medical records of 42 patients were reviewed and assessed for time until patients received an Expanded Disability Status Scale score of 3. Magnetic resonance imaging parameters were dichotomized according to maximum accuracy and then used to calculate hazard ratios using the Cox model for proportional hazard ratios. RESULTS: Conversion to clinically definite multiple sclerosis was observed in 26 patients (62%), of whom 14 (54%) progressed to an Expanded Disability Status Scale score of 3. Two or more infratentorial lesions best predicted long-term disability (hazard ratio, 6.3). Gadolinium-enhancing and hypointense T1-weighted lesions did not show prognostic value. CONCLUSION: Infratentorial lesions are related to long-term prognosis for patients with initial findings suggestive of multiple sclerosis and thus may help to identify patients at high risk for earlier occurrence of clinically relevant disability.     

Benign versus chronic progressive multiple sclerosis: magnetic resonance imaging features

The extent of disease as detected by magnetic resonance imaging was compared between 32 patients with benign multiple sclerosis (MS) and 32 patients with the chronic progressive form matched for age, sex, and disease duration. Computer-assisted quantitation of magnetic resonance images revealed a higher mean lesion load in chronic progressive multiple sclerosis (CPMS); however, in approximately 20% of benign MS patients the lesion load was higher than that in the CPMS patients. CPMS patients had a higher number of infratentorial lesions, yet similar numbers of supratentorial lesions, when compared with benign MS patients. The degree of confluency of lesions and the clinical expression of infratentorial lesions were typically higher in the CPMS patients. Benign MS was characterized by a lower degree of confluency and a higher number of asymptomatic infratentorial lesions. Thus, magnetic resonance imaging shows characteristic differences in magnetic resonance-detected changes between MS patients with different clinical courses.     

Disappearance of hypointense multiple sclerotic lesions on FLAIR MRI.

A child is presented who displayed hypointense multiple sclerotic lesions on fluid-attenuated inversion recovery sequences by magnetic resonance imaging, with the possible pathologic tissue changes of these hypointense lesions evaluated. The magnetic resonance imaging results in this patient demonstrated the disappearance of low-signal lesions on fluid-attenuated inversion recovery in multiple sclerosis, and the improvement of this patient's condition was likely compatible with sequential magnetic resonance imaging findings. Some hypointense lesions in the supratentorial white matter that appear on fluid-attenuated inversion recovery images in multiple sclerosis patients may include reversible brain lesions, suggesting extracellular fluid collection not accompanied by axonal loss or gliosis.     

Conventional magnetic resonance sequences in multiple sclerosis

The role of magnetic resonance imaging (MRI) in multiple sclerosis (MS) has received considerable attention in recent years. MRI has the potential to provide indices of disease activity and progression in clinical trials. Moreover, there is now widespread agreement that conventional MRI sequences are useful not only in diagnosing the disease but also in evaluating the natural course of the disease and the response to therapy. Conventional spin echo (CSE) sequences are widely accepted as sensitive techniques for the evaluation and quantification of brain MS lesions. Fast spin echo (FSE) sequences are now used as an alternative to CSE. They have the advantage of a considerable reduction in imaging time. Fast-fluid attenuation inversion recovery (fast-FLAIR) sequences, in which the signal from cerebrospinal fluid is suppressed, also provide a reliable means to evaluate the total lesion burden in patients with MS. Despite some limitations in the detection of infratentorial lesions, Fast-FLAIR sequences are useful in clinical studies. Compared with lesions load on conventional T2-weighted sequences, an increase in hypointense lesion load on CSE T1-weighted sequences correlates more strongly with increased disability in MS patients. This might be an additional useful MRI parameter to monitor disease progression in long-term studies. Gadolinium-enhanced T1-weighted images provide highly sensitive markers for detecting MRI activity, which represent the primary MRI endpoint for screening promising disease-modifying therapies, especially in phase II trials.     

免疫正常人原发性脑淋巴瘤的MR表现

目的 探讨免疫正常人原发性脑淋巴瘤的MR表现及其诊断价值. 方法 回顾性分析经手术病理证实的15例免疫正常人脑淋巴瘤的MR资料,患者均行常规MR平扫和增强检查. 结果 15例患者共有18个病灶,14个在幕上,4个在幕下.7个病灶有明显的坏死囊变或出血.2例出现柔脑膜转移.在MR的T1WI、T2WI图像上15个病灶实质呈等信号,增强后所有病灶实质呈明显均匀强化,17个病灶表现轻中度占位效应. 结论 免疫正常人原发性脑淋巴瘤幕上多见,MR的T1WI、T2WI图像上肿瘤实质呈等信号,增强后明显均匀强化,有轻度中度占位效应,具有一定特征性.     

Brain atrophy in relapsing-remitting multiple sclerosis: relationship with 'black holes', disease duration and clinical disability

Recent MRI studies in multiple sclerosis have highlighted the potential role of brain atrophy evaluation as a putative marker of disease progression. In the present study, we evaluated the supratentorial and infratentorial brain volume in patients with relapsing remitting multiple sclerosis (RR MS) and in healthy subjects. Moreover, we determined whether brain volumes of MS patients are associated with different aspects of brain MRI abnormalities and clinical findings. Two-dimensional acquired MRI was performed on 52 relapsing-remitting multiple sclerosis and 30 healthy subjects. The volume of supratentorial and infratentorial structures was measured in selected representative slices. Gd-enhancement, T2 hyperintense, T1 hypointense (i.e. 'black holes') total lesion load, as well as the area of corpus callosum was calculated in the MS group and related to brain volume measures. Correlations between MRI parameters and clinical features were also considered. MS patients had significantly lower supratentorial, infratentorial brain volume and corpus callosum area than healthy subjects (P<0.01). Supratentorial brain volume was significantly related to corpus callosum area (r=0.58; P<0.01) and T1 hypointense lesion load (r=0.48; P<0.01), but not with T2 hyperintense lesion load. Infratentorial/supratentorial ratio was significantly associated with disease duration and EDSS score (r=-0.34; P=0.02 and r=-0.49; P<0.01, respectively). This study documents that brain atrophy is an early MRI finding in RR MS and it is closely related to 'black holes' burden. The use of relative values (infratentorial/supratentorial ratio) may increase the conspicuity of correlation between clinical and MRI findings.     

Contribution of MRI to the topography of oculomotor disorders in multiple sclerosis

Magnetic resonance imaging (MRI) was performed in 20 patients with multiple sclerosis and abnormal electro-oculographic examination. All but 2 patients showed MRI abnormalities in the infratentorial region: hypersignal on T2-weighted sequences and/or images of atrophy. Usually, each patient had multiple abnormalities, which could prevent anatomico-oculographic correlations. With oculomotor disorders of cerebellar origin, correlations between clinical findings and MRI images were satisfactory, but with disorders due to brainstem lesions correlations were not so good, as shown by the results in 9 patients with internuclear ophthalmoplegia.     

Neurosarcoidosis: evaluation with MRI

Clinical studies report a rate of 5% and autopsy results a rate of 25% of brain involvement in sarcoidosis. The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of patients with neurosarcoidosis. The MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the clinical information that was provided in the request form. All patients had signs and symptoms referable to the head and were examined with gadolinium enhancement. Cranial (facial) nerve paralysis was the most common clinical manifestation identified in 10 patients. A wide spectrum of MR findings was noted: Periventricular and white matter lesions on T2W spin echo images, mimicking multiple sclerosis (46%); multiple supratentorial and infratentorial brain lesions, mimicking metastases (36%); solitary intraaxial mass, mimicking high grade astrocytoma (9%); solitary extraaxial mass, mimicking meningioma (5%); leptomeningeal enhancement (36%). These findings are not specific for sarcoidosis and one must consider appropriate clinical circumstances in arriving at the correct diagnosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required.     

Inflammatory central nervous system demyelination: Correlation of magnetic resonance imaging findings with lesion pathology

Magnetic resonance imaging (MRI) is widely used to evaluate and monitor disease activity in inflammatory demyelinating central nervous system (CNS) diseases such as multiple sclerosis. The present study aimed at correlating MRI findings with histological parameters in 6 cases of biopsy-proven inflammatory demyelination of the CNS. The earliest stages of demyelinating activity manifested as almost isointense lesions with a massive gadolinium-DTPA (Gd-DTPA) enhancement in T1-weighted scans. In T2-weighted scans, early active lesions formed a border of decreased intensity compared with the lesion center and the perifocal edema. The morphological correlate of this pattern in our patients was activated macrophages in the zone of myelin destruction at the plaque border. Late active lesions were hypointense in T1 and hyperintense in T2 scans. Inactive demyelinated and remyelinating lesions were hyperintense in T2 scans and enhanced inhomogenously after Gd-DTPA application. T1 scans revealed major differences in the degree of hypointensity that correlated with the extent of axonal damage, extracellular edema, and the degree of demyelination or remyelination.     

Does brain degeneration in Wilson disease involve not only copper but also iron accumulation?

Background and purposeWilson disease (WD) is an autosomal recessive inherited disorder of hepatic copper metabolism. Clinical manifestations of WD include neurologic, hepatic and psychiatric symptoms. Most WD patients with the neuropsychiatric form, and some with the hepatic and presymptomatic forms have both hypointense and hyperintense lesions in basal ganglia on T2-weighted magnetic resonance imaging (MRI), which can be iron and copper accumulation. It has been established that T2* and susceptibility-weighted imaging (SWI) are highly sensitive in demonstrating brain iron accumulation, showing decreased signal intensity. Hypointense globus pallidus (GP) signal has been described on T2-, T2*-weighted images and on SWI as typical MRI lesion for patients with neurodegeneration with brain iron accumulation (NBIA). We investigated whether WD patients have MRI changes suggesting iron accumulation using T2*-weighted and VEN_BOLD SWI imaging protocols.Material and methodsStandard MRI with additional sequences (T2*-weighted and VEN_BOLD SWI) was performed in consecutively admitted, clinically stable, and treated patients.ResultsTwenty-eight patients entered the study. Hypointensity in the GP was observed on T2*-weighted images in 10 patients. Using the VEN_BOLD SWI technique, we found hypointense signal in GP in 20 patients.ConclusionsMRI data suggest not only copper but also iron accumulation in GP in WD patients.     

Update on Susac's syndrome

PURPOSE OF VIEW: We review recent developments in the clinical course and imaging modalities for Susac's syndrome, a clinical triad consisting of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. RECENT FINDINGS: Susac's syndrome has variable clinical presentations; recently described presentations include epileptic seizures and transient inverted vision. Advances in neuroradiology suggest that magnetic resonance imaging demonstrates distinctive patterns in the white and grey matter and in the leptomeninges. Reports have verified that Susac's syndrome is under-diagnosed because of its multisystem involvement and confusion with other imitating disorders (such as multiple sclerosis), and because of the fact that neuroradiologists are not acquainted with this syndrome. SUMMARY: The precise aetiology of Susac's syndrome is still unknown and many areas have not yet been explored. Magnetic resonance imaging is the neuroimaging study of choice. Findings include multiple small hyperintense foci on T2-weighted images and contrast enhancement in white and grey matter of both supratentorial and infratentorial structures, corpus callosum and, occasionally, leptomeninges. Callosal lesions typically involve the central fibres and are probably pathognomonic for Susac's syndrome. When assessing patients with unexplained encephalopathy involving white and grey matter, leptomeninges and corpus callosum, the findings of sensorinueral hearing loss or visual disturbances may yield important clues regarding the possibility of Susac's syndrome.     

Cervical cord magnetic resonance imaging findings in systemic immune-mediated diseases

Brain magnetic resonance imaging (MRI) findings in patients with systemic immune-mediated diseases (SID) affecting the central nervous system (CNS) are heterogeneous and lack diagnostic specificity. In the present study, we evaluated the potential role of cervical cord MRI for increasing confidence when making a diagnosis of SID. Sagittal, T2-weighted images of the cervical cord were obtained in patients affected by systemic lupus erythematosus (SLE) with (NSLE, n=9) and without clinical CNS involvement (n=15), Beh?et disease (BD, n=5), Wegener granulomatosis (WG, n=9), antiphospholipid antibody syndrome (APLAS, n=6) and multiple sclerosis (MS, n=10). Spinal cord hyperintense lesions were found in 9/10 MS patients, while no lesions were visible in the cervical cord of any patient with SID, regardless of the presence or absence of brain abnormalities. Cervical cord MRI can be useful in diagnosing patients suspected of having a SID.