Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The quantification of spinal cord (SC) atrophy by MRI has assumed an important role in assessment of neuroinflammatory/neurodegenerative diseases and traumatic SC injury. Recent technical advances make possible the quantification of gray matter (GM) and white matter tissues in clinical settings. However, the goal of a reliable diagnostic, prognostic or predictive marker is still elusive, in part due to large intersubject variability of SC areas. Here, we investigated the sources of this variability and explored effective strategies to reduce it. ⋯ The present work explored in a large cohort of healthy subjects the source of intersubject variability of SC areas and proposes effective normalization methods for its reduction.
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Ultrahigh-field 7T promises more than doubling the signal-to-noise ratio (SNR) of 3T for magnetic resonance imaging (MRI), particularly for MRI of magnetic susceptibility effects induced by B0 . Quantitative susceptibility mapping (QSM) is based on deconvolving the induced phase (or field) and would therefore benefit substantially from 7T. The purpose of this work was to compare QSM performance at 7T versus 3T in an intrascanner test-retest experiment with varying echo numbers (5 and 10 echoes). ⋯ Excellent image quality and good reproducibility was observed. 7T allows equivalent image quality of 3T in half of the scan time.
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We sought to validate ultrasound as a reliable means of assessing vessel stenosis of vertebral artery origins. ⋯ Ultrasound has good sensitivity and excellent specificity for detecting vertebral origin occlusion. Flow velocity can be used to screen for severe stenosis of vertebral artery at origin.
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Transcranial Doppler (TCD) criteria for cerebrovascular stenosis are only based on velocity with unsatisfactory positive predictive value (PPV) in previous studies. We refined a published scoring system that integrates several characteristics of TCD data in diagnosing middle cerebral artery (MCA) stenosis. ⋯ The multiparameter scoring system incorporating several characteristics of TCD measures yielded higher PPV while maintaining high NPV compared with the single-parameter velocity criteria in diagnosing MCA ≥50% stenosis.
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To identify and evaluate diagnostic magnetic resonance imaging (MRI) features in patients with suspicion of discoligamentous cervical injury after hyperextension trauma of the cervical spine. ⋯ MRI is a reliable tool for the evaluation of discoligamentous injuries in the cervical spine, with ancillary features proven as helpful information.