A new semi-automatic method for segmenting the spinal cord from MR images is presented. The method is based on an active surface (AS) model of the cord surface, with intrinsic smoothness constraints. The model is initialized by the user marking the approximate cord center-line on a few representative slices, and the compact surface parametrization results in a rapid segmentation, taking on the order of one minute. Using 3-D acquired T 1 -weighted images of the cervical spine from human controls and patients with multiple sclerosis, the intra-and inter-observer reproducibilities were evaluated, and compared favorably with an existing cord segmentation method. While the AS method overestimated the cord area by approximately 14% compared to manual outlining, correlations between cord cross-sectional area and clinical disability scores confirmed the relevance of the new method in measuring cord atrophy in multiple sclerosis. Segmentation of the cord from 2-D multislice T 2 -weighted images is also demonstrated over the cervical and thoracic region. Since the cord center-line is an intrinsic parameter extracted as part of the segmentation process, the image can be resampled such that the center-line forms one coordinate axis of a new image, allowing simple visualization of the cord structure and pathology; this could find wider application in standard radiological practice.

BACKGROUND AND PURPOSE VBM has been widely used to study GM atrophy in MS. MS lesions lead to segmentation and registration errors that may affect the reliability of VBM results. Improved segmentation and registration have been demonstrated by WM LI before segmentation. DARTEL appears to improve registration versus the USM. Our aim was to compare the performance of VBM-DARTEL versus VBM-USM and the effect of LI in the regional analysis of GM atrophy in MS. MATERIALS AND METHODS 3T T1 MR imaging scans were acquired from 26 patients with RRMS and 28 age-matched NC. LI replaced WM lesions with normal-appearing WM intensities before image segmentation. VBM analysis was performed in SPM8 by using DARTEL and USM with and without LI, allowing the comparison of 4 VBM methods (DARTEL + LI, DARTEL − LI, USM + LI, and USM − LI). Accuracy of VBM was assessed by using NMI, CC, and a simulation analysis. RESULTS Overall, DARTEL + LI yielded the most accurate GM maps among the 4 methods (highest NMI and CC, P < .001). DARTEL + LI showed significant GM loss in the bilateral thalami and caudate nuclei in patients with RRMS versus NC. The other 3 methods overestimated the number of regions of GM loss in RRMS versus NC. LI improved the accuracy of both VBM methods. Simulated data suggested the accuracy of the results provided from patient MR imaging analysis. CONCLUSIONS We introduce a pipeline that shows promise in limiting segmentation and registration errors in VBM analysis in MS.

and neurodegeneration often precede symptom onset in multiple sclerosis (MS).OBJECTIVE To investigate the prevalence of brain magnetic resonance imaging (MRI) and subclinical abnormalities among asymptomatic individuals at risk for MS. DESIGN, SETTING, AND PARTICIPANTSThe Genes and Environment in Multiple Sclerosis (GEMS) project is a prospective cohort study of first-degree relatives of people with MS. Each participant's risk for MS was assessed using a weighted score (Genetic and Environmental Risk Score for Multiple Sclerosis Susceptibility [GERS MS ]) comprising an individual's genetic burden and environmental exposures. The study dates were August 2012 to July 2015. MAIN OUTCOMES AND MEASURESParticipants in the top and bottom 10% of the risk distribution underwent standard and quantitative neurological examination, including disability status, visual, cognitive, motor, and sensory testing, as well as qualitative and quantitative neuroimaging with 3-T brain MRI and optical coherence tomography. RESULTSThis study included 100 participants at risk for MS, with 41 at higher risk (40 women [98%]) and 59 at lower risk (25 women [42%]), at a mean (SD) age of 35.1 (8.7) years. Given the unequal sex distribution between the 2 groups, the analyses were restricted to women (n = 65). When considering all measured outcomes, higher-risk women differed from lower-risk women (P = .01 by omnibus test). Detailed testing with a vibration sensitivity testing device in a subgroup of 47 women showed that higher-risk women exhibited significantly poorer vibration perception in the distal lower extremities (P = .008, adjusting for age, height, and testing date). Furthermore, 5 of 65 women (8%) (4 at higher risk and 1 at lower risk) met the primary neuroimaging outcome of having T2-weighted hyperintense brain lesions consistent with the 2010 McDonald MRI criteria for dissemination in space. A subset of participants harbor many different neuroimaging features associated with MS, including perivenous T2-weighted hyperintense lesions and focal leptomeningeal enhancement, consistent with the hypothesis that these individuals are at higher risk of developing clinical symptoms of MS than the general population.CONCLUSIONS AND RELEVANCE Higher-risk asymptomatic family members of patients with MS are more likely to have early subclinical manifestations of MS. These findings underscore the importance of early detection in high-risk individuals.TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01353547

Objective Spinal cord atrophy is prominent in chronic progressive neurologic diseases such as Human-T-cell lymphotropic virus type-1 (HTLV-1) associated myelopathy/tropical spastic paraparesis (HAM/TSP) and multiple sclerosis (MS). Here we compared the spinal cord cross-sectional area (SCCSA) in HAM/TSP and MS to that of healthy volunteers (HV). Methods SCCSA and clinical disability scores were measured in 18 HAM/TSP, 4 asymptomatic carriers (AC) of HTLV-1, 18 MS, and 10 HV from a 3T MRI. SCCSA measured in patients and AC were compared to that of HV and correlated with disability scores. Results The entire spinal cord in HAM/TSP was thin compared to HV, whereas only the cervical cord in MS was thinner than HV (p<0·0001). In HAM/TSP, SCCSA extensively correlated with Ambulation Index, whereas only the cervical cord correlated with disease duration (p<0·05). In MS, the SCCSA extensively correlated with Scripps Neurologic Rating Score and the Expanded Disability Status Scale (p<0·05). One of the four ACs showed atrophy in a pattern similar to HAM/TSP. Interpretation These results are in accordance with the findings that whereas over half of all lesions in an MS cord are seen in the upper cervical cord, most of the pathology in HAM/TSP is seen in the thoracolumbar cord, which in turn may be responsible for more extensive cord atrophy seen in HAM/TSP. Imaging marker such as SCCSA might serve as a surrogate endpoint in clinical trials, especially to assess the neuroprotective impact of various therapies.