title: The influence of slice orientation on brain MRI lesion load measurement in multiple sclerosis.
abstract: This study aimed at evaluating the influence of a different slice orientation on brain magnetic resonance imaging (MRI) lesion load in multiple sclerosis (MS). Fifteen MS patients were scanned obtaining both axial and sagittal conventional spin echo (24 slices; TR 2400, TE 30/80) brain MRI. The total lesion load (TLL) was assessed twice for each scan, using a semi-automated local thresholding technique and the same marked hardcopies. The mean TLL was 22734 mm3 for axial and 22003 mm3 for sagittal scans. The mean intra-observer coefficient of variation (COV) was 4.65% for the axial acquisitions and 4.52% for the sagittal acquisitions. This difference was not statistically significant (one-way ANOVA, P > 0.1). The lesion load was significantly higher from axial MRI as compared to the intra-observer variability (two-way ANOVA, P=0.01), but the fluctuations around this average difference between axial and sagittal scan TLL were significantly large (test for interaction, P < 0.001). Our data indicate that the use of sagittal conventional MRI scans does not seem to be worthwhile for the quantitative assessment of lesion load in MS patients.
authors.affiliation: MS Biosignal Analysis Center, Department of Neurology, IRCCS Ospedale San Raffaele, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rovaris
authors.forename: M P
authors.initials: MP
authors.lastname: Sormani
authors.forename: M A
authors.initials: MA
authors.lastname: Rocca
authors.forename: G
authors.initials: G
authors.lastname: Comi
authors.forename: M
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis*; D015588:Observer Variation