title: T1ρ and T2 -based characterization of regional variations in intervertebral discs to detect early degenerative changes.
abstract: Lower back pain is one of the main contributors to morbidity and chronic disability in the United States. Despite the significance of the problem, it is still not well understood. There is a clear need for objective, non-invasive biomarkers to localize specific pain generators and identify early stage changes to enable reliable diagnosis and treatment. In this study we focus on intervertebral disc degeneration as a source of lower back pain. Quantitative imaging markers T1ρ and T2 have been shown to be promising techniques for in vivo diagnosis of biochemical degeneration in discs due to their sensitivity to macromolecular changes in proteoglycan content and collagen integrity. We describe a semi-automated technique for quantifying T1ρ and T2 relaxation time maps in the nucleus pulposus (NP) and the annulus fibrosus (AF) of the lumbar intervertebral discs. Compositional changes within the NP and AF associated with degeneration occur much earlier than the visually observable structural changes. The proposed technique rigorously quantifies these biochemical changes taking into account subtle regional variations to allow interpretation of early degenerative changes that are difficult to interpret with traditional MRI techniques and clinical subjective grading scores. T1ρ and T2 relaxation times in the NP decrease with degenerative severity in the disc. Moreover, standard deviation and texture measurements of these values show sharper and more significant changes during early degeneration compared to later degenerative stages. Our results suggest that future prospective studies should include automated T1ρ and T2 metrics as early biomarkers for disc degeneration-induced lower back pain. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1373-1381, 2016.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 1700 4th Street, Suite 203, San Francisco, California 94158.
authors.forename: Prachi
authors.initials: P
authors.lastname: Pandit
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 1700 4th Street, Suite 203, San Francisco, California 94158.
authors.forename: Jason F
authors.initials: JF
authors.lastname: Talbott
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 1700 4th Street, Suite 203, San Francisco, California 94158.
authors.forename: Valentina
authors.initials: V
authors.lastname: Pedoia
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 1700 4th Street, Suite 203, San Francisco, California 94158.
authors.forename: William
authors.initials: W
authors.lastname: Dillon
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 1700 4th Street, Suite 203, San Francisco, California 94158.
authors.forename: Sharmila
authors.initials: S
authors.lastname: Majumdar
mesh_terms: D000328:Adult; D000070616:Annulus Fibrosus / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging*; D017116:Low Back Pain / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D000070614:Nucleus Pulposus / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: T1ρ/T2; degenerative disc disease; intervertebral disc degeneration; lumbar spine; quantitative MRI