title: An in vivo MRI study of the changes in volume (and fluid content) of the lumbar intervertebral disc after overnight bed rest and during an 8-hour walking protocol.
abstract: Magnetic resonance imaging (MRI) was used to measure the changes in the volume (and fluid content) of the lumbar intervertebral discs (L1-L2, L2-L3, L3-L4, L4-L5) in five normal subjects. For each subject, MRI scans were taken at the end of a normal day and again on the following morning (after a night's bed rest). Ten further scans were taken during an 8-h protocol consisting of alternate periods of walking (40 min) and scanning (10 min). On average, 1) disc volume increased by 10.6% during overnight bed rest, which corresponds to a gain of about 0.9 cm(3) of fluid; 2) the rate of disc volume decrease during the 8-h walking protocol was 0.96 x 10(-3) cm(3)/min; and 3) after 8 h (using our walking/scanning protocol), the disc volume did not decrease to the volume measured at the end of the previous day.
authors.affiliation: Department of Radiology, Emory University School of Medicine, Atlanta 30303, USA. jmalko@emory.edu
authors.forename: John A
authors.initials: JA
authors.lastname: Malko
authors.forename: William C
authors.initials: WC
authors.lastname: Hutton
authors.forename: William A
authors.initials: WA
authors.lastname: Fajman
mesh_terms: D000328:Adult; D001510:Bed Rest; D005110:Extracellular Space / Q000502:physiology*; D005260:Female; D018495:Fluid Shifts; D006801:Humans; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000502:physiology*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D016138:Walking