title: Monitoring of the effect of intervertebral disc nucleus pulposus ablation by MRI.
abstract: In order to investigate intervertebral disc (IVD) degeneration and repair, a quantitative non-invasive tool is needed. Various MRI methods including qCPMG, which yields dipolar echo relaxation time (T(DE)), magnetization transfer contrast (MTC), and (1)H and (2)H double quantum filtered (DQF) MRI were used in the present work to monitor changes in rat IVD after ablation of the nucleus pulposus (NP), serving as a model of severe IVD degeneration. In the intact IVD, a clear distinction between the annulus fibrosus (AF) and the NP is obtained on T(2) and T(DE) weighted images as well as on MTC maps, reflecting the high concentration of ordered collagen fibers in the AF. After ablation of the NP, the distinction between the compartments is lost. T(2) and T(DE) relaxation times are short throughout the disc and MTC is high. (1)H and (2)H DQF signal, which in intact discs is obtained only for the AF, is now observable throughout the tissue. These results indicate that after ablation, there is an ingression of collagen fibers from the AF into the area that was previously occupied by the NP, as was confirmed by histology.
authors.affiliation: School of Chemistry, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Galit
authors.initials: G
authors.lastname: Saar
authors.forename: Yoram
authors.initials: Y
authors.lastname: Zilberman
authors.forename: Hadassah
authors.initials: H
authors.lastname: Shinar
authors.forename: Keren
authors.initials: K
authors.lastname: Keinan-Adamsky
authors.forename: Gadi
authors.initials: G
authors.lastname: Pelled
authors.forename: Dan
authors.initials: D
authors.lastname: Gazit
authors.forename: Gil
authors.initials: G
authors.lastname: Navon
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000378:metabolism / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003094:Collagen