Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Eddy current distortion is an important issue that may influence the quantitative measurements of diffusion tensor imaging (DTI). The corrections of eddy current artifacts could be performed using bipolar diffusion gradients or unipolar gradients with affine registration. Whether the diffusion pulse sequence affects the quantification of DTI indices and the technique that produces more reliable DTI indices in terms of reproducibility both remain unclear. ⋯ The results revealed that the reproducibility and mean values of DTI indices were significantly affected by the pulse sequence. Unipolar DTI exhibited significantly higher reproducibility than bipolar DTI even at the same TE, and the mean values of DTI indices were significantly different between them. Therefore, we concluded that the reproducibility and mean values of DTI indices were significantly influenced by diffusion pulse sequences.
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Though still debated, early reperfusion is increasingly used as a biomarker for clinical outcome. However, the lack of a standard definition hinders the assessment of reperfusion therapies and study comparisons. The objective was to determine the optimal early reperfusion criteria that predicts clinical outcome in ischemic stroke. ⋯ TTP and Tmax should be preferred to MTT in defining early reperfusion. GBTM provided a clinically relevant reperfusion classification that does not require prespecified delay thresholds or clinical outcomes.
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To determine if patients with relapsing-remitting multiple sclerosis (RRMS) have a reduced brain stem cross-sectional area (CSA) compared to age- and sex-matched controls. The brain stem is a common site of involvement in MS. However, relatively few imaging studies have investigated brain stem atrophy. ⋯ A significantly reduced, normalized brain stem CSA was detected in all areas of the brain stem of the RRMS patients, when compared to age- and gender-matched controls. Lack of detectable upper cervical cord atrophy in the same patients suggests some independence of the MS pathology in these regions.
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To compare corpus callosum area (CCA) and corpus callosum index (CCI) in terms of feasibility and their performance as biomarkers for cognitive and physical disability in multiple sclerosis (MS). A secondary aim was to compare these two methods with volumetric measurements. ⋯ CCA is a time-effective and robust biomarker that has stronger correlations with both EDSS and information processing speed than CCI and volumetric measurements that are commonly used as outcome measures in MS research and clinical trials.
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Susceptibility weighted imaging and assessment of intratumoral susceptibility signal (ITSS) morphology is used to identify high-grade glioma (HGG) in patients with suspected brain neoplasm. ⋯ Our findings indicate that ITSS-morphology is not a random phenomenon. Location of GB, as well as tumor volume, appear to be factors contributing to ITSS morphology.