Automated Integration of Multimodal MRI for the Probabilistic Detection of the Central Vein Sign in White Matter Lesions.

BACKGROUND AND PURPOSE: The central vein sign is a promising MR imaging diagnostic biomarker for multiple sclerosis. Recent studies have demonstrated that patients with MS have higher proportions of white matter lesions with the central vein sign compared with those with diseases that mimic MS on MR imaging. However, the clinical application of the central vein sign as a biomarker is limited by interrater differences in the adjudication of the central vein sign as well as the time burden required for the determination of the central vein sign for each lesion in a patient's full MR imaging scan. In this study, we present an automated technique for the detection of the central vein sign in white matter lesions. MATERIALS AND METHODS: Using multimodal MR imaging, the proposed method derives a central vein sign probability, πij, for each lesion, as well as a patient-level central vein sign biomarker, ψi. The method is probabilistic in nature, allows site-specific lesion segmentation methods, and is potentially robust to intersite variability. The proposed algorithm was tested on imaging acquired at the University of Vermont in 16 participants who have MS and 15 participants who do not. RESULTS: By means of the proposed automated technique, participants with MS were found to have significantly higher values of ψ than those without MS (ψMS = 0.55 ± 0.18; ψnon-MS = 0.31 ± 0.12; P < .001). The algorithm was also found to show strong discriminative ability between patients with and without MS, with an area under the curve of 0.88. CONCLUSIONS: The current study presents the first fully automated method for detecting the central vein sign in white matter lesions and demonstrates promising performance in a sample of patients with and without MS.

Identification of Chronic Active Multiple Sclerosis Lesions on 3T MRI.

BACKGROUND AND PURPOSE: MR imaging-pathologic studies have reported that paramagnetic rims on 7T susceptibility-based MR imaging identify, in vivo, the subset of MS lesions with compartmentalized inflammation at the lesion edge and associated remyelination failure. Here, we assessed the reliability of detecting these rims on high-resolution 3T phase images. MATERIALS AND METHODS: High-resolution T2* and phase MR imaging was collected in 20 patients with MS at 3T (3D segmented EPI, 0.65 mm3) and 7T (2D gradient-echo, 0.2 × 0.2 × 1 mm) MR imaging. In each case, 5 discrete chronic (nonenhancing) MS lesions were selected on T2 FLAIR images for rim evaluation. Five raters experienced in MS imaging contributed to the rim assessment, of whom 3 worked independently on 3T data, and 2, on 7T data. Consensus agreement was reached for both 3T and 7T rim evaluations. Discrepancies between 3T and 7T were discussed, and consensus was reached. RESULTS: Phase rims were seen in 34 lesions at 7T and in 36 lesions at 3T by consensus. Inter- and intrarater reliability were "substantial/good" both at 3T and 7T analysis (Cohen κ, >0.71). Based on consensus agreement, the reliability of rim visualization at 3T versus 7T was 0.78 (κ) with a pair-wise agreement of 90%. More lesions were judged to be false-positive or false-negative at 3T than at 7T. CONCLUSIONS: Nearly all 7T paramagnetic rims can also be seen at 3T. Imaging at 3T opens the possibility of implementing paramagnetic rims as an outcome measure in multicenter, MR imaging-based clinical trials aimed at treating perilesional persistent inflammation and its potential effects on remyelination.

Faculty attitudes toward the use of audiovisuals in continuing education.

A study was undertaken in planning for a project involving library support for formal continuing education programs. A questionnaire survey assessed faculty attitudes toward continuing education activities, self-instructional AV programs for continuing education, and self-instructional AV programs for undergraduate medical education. Actual use of AV programs in both undergraduate and postgraduate classroom teaching was also investigated. The results indicated generally positive attitudes regarding a high level of classroom use of AV programs, but little assignment of audiovisuals for self-instruction.