title: Multisequence-imaging protocols to detect cortical lesions of patients with multiple sclerosis: observations from a post-mortem 3 Tesla imaging study.
abstract: Neocortical lesions (NLs) are an important component of multiple sclerosis (MS) pathology and may account for part of the physical and cognitive disability. Visualizing NLs of patients with MS using magnetic resonance imaging (MRI) poses several significant challenges. We optimized the inversion time (TI) of T(1)-based magnetization-prepared rapid acquisition gradient-echo (MPRAGE) images by suppressing the signal of the lesions and enhancing their appearance as hypointensities, on the basis of the derived quantitative T(1) measurements. The latter were achieved by the means of 2D inversion recovery fast spin echo (IR-FSE), repeated using different inversion times (TI). Comparisons of detection of NLs by MPRAGE and dual echo T(2) weighted (T(2)W) and proton density (PD) W. Four coronal brain slices from a deceased MS patient and two coronal brain slices from two formerly healthy donors were imaged using a 3 Tesla magnet (3 T) equipped with a multi-channel coil. Based upon the averaged T1 values computed from the MS specimen as well as visual inspection, an optimal TI of 380 ms was selected for the MPRAGE image. No NLs were seen in the specimens of the two healthy donors. Of the 40 total NLs observed, 8 (20%) were visible in all three sequences employed. Three (7.5%) NLs were visible only in the PDW image and 5 (12.5%) were seen only in the T(2)W image. Four NLs (10%) had clearly unique conspicuity in the MPRAGE image. Of those, 3 were retrospectively scored in the PDW image (1 NL) or in the T2W image (2 NLs). We conclude that for the detection of MS-related NLs, high-resolution T(1)-based MPRAGE and T(2)-W images offer complementary information and the combination of the two image sequences is crucial for increasing the sensitivity of detecting MS-induced NLs.
authors.affiliation: Neuroimmunology Branch (NIB), National Institute of Neurological Disorders and Stroke (NINDS), NIH, Bethesda, MD 20892-1400, USA. bagnatof@ninds.nih.gov
authors.forename: Francesca
authors.initials: F
authors.lastname: Bagnato
authors.forename: Bing
authors.initials: B
authors.lastname: Yao
authors.forename: Fredric
authors.initials: F
authors.lastname: Cantor
authors.forename: Hellmut
authors.initials: H
authors.lastname: Merkle
authors.forename: Ellen
authors.initials: E
authors.lastname: Condon
authors.forename: Marcela
authors.initials: M
authors.lastname: Montequin
authors.forename: Sandra
authors.initials: S
authors.lastname: Moore
authors.forename: Martha
authors.initials: M
authors.lastname: Quezado
authors.forename: Deborah
authors.initials: D
authors.lastname: Tkaczyk
authors.forename: Henry
authors.initials: H
authors.lastname: McFarland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009103:Multiple Sclerosis / Q000473:pathology*