Relapsing neuromyelitis optica and relapsing-remitting multiple sclerosis: differentiation at diffusion-tensor MR imaging of corpus callosum

PURPOSE: To prospectively assess sensitivity and specificity of diffusion indexes of the corpus callosum (CC) for differentiating relapsing neuromyelitis optica (RNMO) from relapsing-remitting multiple sclerosis (RRMS), by using final clinical diagnosis as the reference standard. MATERIALS AND METHODS: Participants provided informed consent; the study was approved by the institutional review board. Forty-six consecutive patients with RRMS (18 men, 28 women; mean age, 37.7 years; range, 18-58 years) and 26 consecutive patients with RNMO (two men, 24 women; mean age, 38.6 years; range, 19-59 years) underwent diffusion-tensor magnetic resonance imaging. Mean diffusivity (MD) and fractional anisotropy (FA) of the region of interest (ROI) of the CC in the midsagittal plane were measured and used as discriminative indexes. Bayesian classification with leave-one-out cross-validation was used to determine diagnostic accuracy. Differences in diffusion indexes of ROIs among groups were evaluated by using the Kruskal-Wallis test, followed by the Mann-Whitney U test for multiple comparisons and Bonferroni correction. RESULTS: Mean MD (8.48 x 10(-4) mm(2)/sec) and FA (0.729) of the ROI in patients with RNMO were significantly (P<.001) different from those (MD=10.64 x 10(-4) mm(2)/sec, FA=0.599) in patients with RRMS. Sensitivity and specificity for differentiation were 92.3% (24 of 26 patients with RNMO) and 93.5% (43 of 46 patients with RRMS) for FA and 88.5% (23 of 26 patients with RNMO) and 89.1% (41 of 46 patients with RRMS) for MD, respectively. CONCLUSION: Measurement of diffusion indexes of the CC may be useful for distinguishing patients with RNMO from those with RRMS.     

Preferential occult injury of corpus callosum in multiple sclerosis measured by diffusion tensor imaging

PURPOSE: To investigate the feasibility of diffusion tensor imaging (DTI) assessment of microscopic fiber tract injury in the corpus callosum (CC) and other normal-appearing white matter (NAWM) in patients with early multiple sclerosis (MS). MATERIALS AND METHODS: DTI was performed in 12 healthy volunteers and 15 patients who have relatively short disease duration (mean = 2.7 years). Both fractional anisotropy (FA) and mean diffusivity (MD) were obtained in different regions of normal-appearing CC (NACC) and NAWM in frontal and occipital regions. RESULTS: The data showed significantly lower FA (P < 0.001) and higher MD (P < 0.04) for NACC regions, but not for frontal and occipital NAWM regions, in patients than in those in healthy volunteers after Bonferroni adjustment. The increase of MD in the entire NACC regions was correlated with the total cerebral lesion volume (r = 0.75, P = 0.001) in patients. CONCLUSION: The water diffusion changes indicate that in the early phase of disease there is a preferential occult injury of CC, which is likely due to the Wallerian degeneration from distant lesions.     

Fractional anisotropy and mean diffusivity in the corpus callosum of patients with multiple sclerosis: the effect of physiotherapy

Introduction  

Modulation of neurodegeneration by physical activity is an active topic in contemporary research. The purpose of this study was to investigate changes in the brain's microstructure in multiple sclerosis (MS) after facilitation physiotherapy.     

Differentiating multiple sclerosis from other causes of demyelination using diffusion weighted imaging of the corpus callosum

Purpose

To compare diffusion weighted imaging metrics in gray and white matter brain regions of patients diagnosed with multiple sclerosis (MS) to those diagnosed with secondary demyelinating diseases such as neurosarcoid and acute disseminated encephalomyelitis (ADEM).

Materials and Methods

Diffusion weighted scans were performed and apparent diffusion coefficients of 12 regions of interest were determined in 30 MS patients, 21 neurosarcoid patients, and 4 ADEM patients.

Results

Mean apparent diffusion coefficients were significantly higher in MS patients than in non‐MS patients in 6 of 6 of the corpus callosal regions assessed but not in any of the non‐callosal white or gray matter regions assessed.

Conclusion

Elevated apparent diffusion coefficients within the corpus callosum on diffusion weighted imaging may potentially help differentiate between patients with MS and patients with other diseases affecting the central nervous system white matter. J. Magn. Reson. Imaging 2009;30:732–736. © 2009 Wiley‐Liss, Inc.     

MR imaging findings of the corpus callosum region in the differentiation between multiple sclerosis and neuromyelitis optica

Purpose

To evaluate MR imaging findings in corpus callosum region for the discrimination between opticospinal multiple sclerosis (OSMS) and neuromyelitis optica (NMO).

Materials and methods

Forty-two definite OSMS with seronegative NMO-IgG and 23 NMO with seropositive NMO-IgG, and 27 age-matched normal controls (NC) were recruited. Sagittal T2-FLAIR images with 2-mm slice thickness were obtained. Subcallosal dot-dash (SCDD) sign and subcallosal striations (SCS) sign were reviewed.

Results

SCDD was more commonly detected in OSMS (28 of 42 patients) than in NMO (5 of 23 patients) (P < 0.05). SCS showed no difference between OSMS (31 of 42 patients) and NMO (12 of 23 patients) (P > 0.05). For comparing ROC analysis among SCDD, SCS, and SCDD + SCS for predicted probability through binary logistic regression analysis, SCDD + SCS had the largest area under ROC curve (0.777) than SCDD (0.725) and SCS (0.608).

Conclusion

SCDD may be helpful in distinguishing OSMS from NMO. The regression equation may also be a simple and effective method of choice for the differentiation between OSMS and NMO.     

Multiple sclerosis and corpus callosum atrophy: Relationship of MRI findings to clinical data

Summary Among 110 patients (45 men, 65 women), aged 15 to 66, with clinical and/or biological diagnosis of multiple sclerosis (MS), severe to moderate corpus callosum (CC) atrophy was observed in 67 (60%) patients. Correlation between CC atrophy, brain atrophy, duration and severity of clinical symptoms, and high signal white matter areas, was carried out in 90 patients. Mean age was 46 years for those with severe CC atrophy, and 33 years for those without atrophy. Mean duration of the disease was 14 years in patients with severe atrophy, and 5 years in patients without atrophy. Severity of clinical symptoms is more pronounced in patients with severe CC atrophy. Numerous or large white matter high signal areas are observed in patients with severe CC atrophy on T2-weighted images. CC atrophy appears earlier than brain atrophy in the course of MS.     

Involvement of corpus callosum in amyotrophic lateral sclerosis shown by MRI

Abnormal high signal in the corticospinal tracts on MRI has been described in amyotrophic lateral sclerosis. We report a case with further high signal in fibres of the corpus callosum on proton density and T2-weighted spin-echo images, closely matching findings of earlier pathological reports.     

Correlation of diffusion tensor and dynamic perfusion MR imaging metrics in normal-appearing corpus callosum: support for primary hypoperfusion in multiple sclerosis

BACKGROUND AND PURPOSE: Hypoperfusion of the normal-appearing white matter in multiple sclerosis (MS) may be related to ischemia or secondary to hypometabolism from wallerian degeneration (WD). This study evaluated whether correlating perfusion and diffusion tensor imaging (DTI) metrics in normal-appearing corpus callosum could provide support for an ischemic mechanism for hypoperfusion. MATERIALS AND METHODS: Fourteen patients with relapsing-remitting MS (RRMS) and 17 control subjects underwent perfusion MR imaging and DTI. Absolute measures of cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were calculated. Mean diffusivity (MD) and fractional anisotropy (FA) maps were computed from DTI data. After visual coregistration of perfusion and DTI images, regions of interest were placed in the genu, central body, and splenium of normal-appearing corpus callosum. Pearson product-moment correlation coefficients were calculated using mean DTI and perfusion measures in each region. RESULTS: In the RRMS group, CBF and CBV were significantly correlated with MD in the splenium (r = 0.83 and r = 0.63, respectively; both P < .001) and in the central body (r = 0.86 and r = 0.65, respectively; both P < .001), but not in the genu (r = 0.23 and 0.25, respectively; both P is nonsignificant). No significant correlations were found between MTT and DTI measures or between FA and any perfusion measure in the RRMS group. No significant correlations between diffusion and perfusion metrics were found in control subjects. CONCLUSION: In the normal-appearing corpus callosum of patients with RRMS, decreasing perfusion is correlated with decreasing MD. These findings are more consistent with what would be expected in primary ischemia than in secondary hypoperfusion from WD.     

Lower fractional anisotropy at the anterior body of the normal-appearing corpus callosum in multiple sclerosis versus symptomatic carotid occlusion

Introduction  Not uncommonly, differentiating multiple sclerosis (MS) from ischemic cerebral vascular disease is difficult based on conventional magnetic resonance imaging (MRI). We aim to determine whether preferential occult injury in the normal-appearing corpus callosum (NACC) is more severe in patients with MS than symptomatic carotid occlusion by comparing fractional anisotropy (FA) from diffusion tensor imaging (DTI). Methods  Eighteen patients (eight men, ten women; mean age, 38.6 years) with MS and 32 patients (24 men, eight women; mean age, 64.0 years) with symptomatic unilateral internal carotid occlusion were included. DTI (1.5 T) were performed at corpus callosum which were normal-appearing on fluid-attenuated inversion recovery MRI. Mean FA was obtained from the genu, anterior body, posterior body, and splenium of NACC. Independent-sample t test statistical analysis was performed. Results  The FA values in various regions of NACC were lower in the MS patients than symptomatic carotid occlusion patients, which was statistically different at the anterior body (0.67 ± 0.12 vs 0.74 ± 0.06, P = 0.009), but not at genu, posterior body, and splenium (0.63 ± 0.09 vs 0.67 ± 0.07, P = 0.13; 0.68 ± 0.09 vs 0.73 ± 0.05, P = 0.07; 0.72 ± 0.09 vs 0.76 ± 0.05, P = 0.13). Conclusion  MS patients have lower FA in the anterior body of NACC compared to patients with symptomatic carotid occlusion. It suggests that DTI has potential ability to differentiate these two conditions due to the more severe preferential occult injury at the anterior body of NACC in MS.     

Corpus callosum and subcallosal-periventricular lesions in multiple sclerosis: detection with MR

Examination with magnetic resonance imaging of 40 patients with confirmed diagnoses of multiple sclerosis showed that corpus callosum involvement is common. Thirty percent of the patients had focal callosal lesions similar to those described in the pathology literature. Long, inner callosal-subcallosal lesions were found in 55% of patients. These lesions had signal characteristics similar to those of noncallosal periventricular lesions. Diffuse moderate to severe atrophy of the corpus callosum was noted in 40% of patients, with one exception concurrent with inner callosal lesions. The nature of the inner callosal lesions is not known, since these lesions are not typically described in the literature. These lesions may represent demyelination or increased water content and may be the precursor to atrophy that progresses from the ependymal surface toward the outer fibers of the corpus callosum.     

Diffusion tensor fractional anisotropy of the normal-appearing seven segments of the corpus callosum in healthy adults and relapsing-remitting multiple sclerosis patients

PURPOSE: To investigate the utility of whole-brain diffusion tensor imaging (DTI) in elucidating the pathogenesis of multiple sclerosis (MS) using the normal-appearing white matter (NAWM) of the corpus callosum (CC) as a marker of occult disease activity. MATERIALS AND METHODS: A high signal-to-noise ratio (SNR) and optimized entire brain DTI data were acquired in 26 clinically-definite relapsing and remitting multiple sclerosis (RRMS) patients and 32 age-matched healthy adult controls. The fractional anisotropy (FA) values of seven functionally distinct regions in the normal-appearing CC were compared between patients and controls. RESULTS: This study indicates that 1) there was a gender-independent FA heterogeneity of the functionally specialized CC segments in normal volunteers; 2) FA in the MS group was significantly decreased in the anterior (P=0.0039) and posterior (P=0.0018) midbody subdivisions of the CC, possibly due to a reduction of small-caliber axons; and 3) the FA of the genu of the CC was relatively intact in the MS patients compared to the healthy age-matched controls (P=0.644), while the splenium showed an insignificant trend of reduced FA values (P=0.248). The decrease in FA in any of the CC subdivisions did not correlate with disease duration (DD) or the expanded disability status scale (EDSS) score. CONCLUSION: The preliminary results are consistent with published histopathology and clinical studies on MS, but not with some published DTI reports. This study provides insights into the pathogenesis of MS, and the role played by compromised axonal integrity in this disease.     

Abnormal cervical lymph nodes in multiple sclerosis: a preliminary ultrasound study

Background

Cervical lymph nodes are the first drainage stations of the brain and therefore play a key role in neuroinflammatory disorders such as multiple sclerosis.

Objective

The aim of this study was to evaluate, by using ultrasound imaging, cervical lymph nodes in patients with multiple sclerosis and to ascertain if such patients have any clinical features to attest their role.

Methods

We enrolled 43 patients affected by relapsing–remitting multiple sclerosis (22 drug free and 21 under treatment with natalizumab or fingolimod), who underwent ultrasound examination. The morphology, diameters and volume of cervical lymph nodes were measured. We evaluated also a control group of 20 healthy volunteers.

Results

Between-group comparisons showed that the mean anteroposterior diameters in the cervical lymph nodes on both sides of the neck were significantly different (χ ² = 19.5, p < 0.001 for right; χ ² = 20.0, p < 0.001 for left). Post hoc contrasts showed that the mean anteroposterior diameters were greater both in drug-naive (mean ± SD 0.66 ± 0.20 cm; p < 0.001) and treated patients (0.55 ± 0.24 cm; p < 0.001) compared to healthy individuals (0.36 ± 0.19 cm). Moreover, significant difference (p < 0.001) was shown on comparing the mean volume of the cervical lymph nodes on both sides of the neck in the studied groups. No significant differences emerged between the drug-free and treated patients.

Conclusion

The abnormalities shown by ultrasound in cervical lymph nodes are related to deep ones and independent of the ongoing treatment, suggesting a relationship between lymphatic drainage and disease pathology.

     

Dysgenesis of the corpus callosum

Summary The embryology of the corpus callosum is briefly reviewed in relation to dysgenesis and associated malformations. The morphology, etiology, clinical and radiological features of such malformations are discussed and illustrated.     

Agenesis of the corpus callosum

This paper presents a case of a sixteen-year-old female patient with agenesis of corpus callosum which was accidentally discovered during etiological investigation of the consciousness disorder. Agenesis of corpus callosum, a rare congenital defect, might be associated with macrocephalia and various degrees of mental impairment, optic defects, and seizures. Apart from patients with these pathologic states, there are individuals with agenesis of corpus callosum, but without any clinical disturbances.     

胼胝体肿瘤的影像学诊断

目的 探讨发生于胼胝体的不同类型肿瘤的影像学表现.方法 回顾性分析25例发生于胼胝体的不同类型的肿瘤.分析各种肿瘤在不同影像学检查方法下的表现特点.结果 低级别星形细胞瘤1例,间变性星形细胞瘤2例,胶质母细胞瘤7例,少突胶质细胞瘤1例,间变性少突星形细胞瘤1例,少突一星形细胞瘤1例,原发恶性淋巴瘤10例,转移瘤1例,脂肪瘤1例.肿瘤最大直径7 cm,最小0.5 cm.肿瘤实性部分T1WI为等或低信号,T2WI为等或稍高信号,部分肿瘤伴囊变坏死.脂肪瘤CT平扫为低密度,CT值-85 HU.增强扫描星形细胞瘤呈不均匀、环状或蝶翼状强化,恶性淋巴瘤呈明显实性或环状强化,胶质母细胞瘤和淋巴瘤多向脑室或邻近脑质浸润.结论 胼胝体肿瘤的影像学表现具有特征性,可为手术切除肿瘤提供指导作用.     

胼胝体肿瘤的影像学诊断

目的 探讨发生于胼胝体的不同类型肿瘤的影像学表现.方法 回顾性分析25例发生于胼胝体的不同类型的肿瘤.分析各种肿瘤在不同影像学检查方法下的表现特点.结果 低级别星形细胞瘤1例,间变性星形细胞瘤2例,胶质母细胞瘤7例,少突胶质细胞瘤1例,间变性少突星形细胞瘤1例,少突一星形细胞瘤1例,原发恶性淋巴瘤10例,转移瘤1例,脂肪瘤1例.肿瘤最大直径7 cm,最小0.5 cm.肿瘤实性部分T1WI为等或低信号,T2WI为等或稍高信号,部分肿瘤伴囊变坏死.脂肪瘤CT平扫为低密度,CT值-85 HU.增强扫描星形细胞瘤呈不均匀、环状或蝶翼状强化,恶性淋巴瘤呈明显实性或环状强化,胶质母细胞瘤和淋巴瘤多向脑室或邻近脑质浸润.结论 胼胝体肿瘤的影像学表现具有特征性,可为手术切除肿瘤提供指导作用.