TITLE:
Normalized intervertebral disc MRI signal as a biomarker of pain
AUTHORS:
Mohamed Aissiou, Delphine Périé, Jean-Marc Mac-Thiong
KEYWORDS:
MRI; Intervertebral Disc; Normalized Signal Intensity; Low Back Pain; Vertebral Fractures
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.6 No.3A,
March
29,
2013
ABSTRACT: The drop in the MRI signal intensity, analysed without
any normalisation, was found related to the intervertebral disc degeneration,
but its association with low back pain remains controversial. The authors
developed the analysis of MR signal intensity distribution (AMRSID) method that
analyzes the 3D distribution of the normalized T2-weighted MR signal
intensity within the intervertebral disc using descriptive statistics of
histograms and weighted centers. In this study, we hypothesized that the
distribution of the normalized MRI signal intensity within T2- weighted images
of the intervertebral disc is a bio-marker of low back pain (LBP)
independently of age and disc degenerescence. The aims were to: 1) characterize
intervertebral disc degeneration in vertebral fracture from MR T1-weighted and
T2-weighted images; 2) evaluate the sensitivity of the normalized MRI signal
distribution to the presence of LBP, discs height loss and aging. We
prospectively studied 22 patients who underwent an MRI acquisition within 48h
after an accidental lumbar vertebral fracture. The presence of prefracture low
back pain, spinal stenosis, annular
disruption, intervertebral disc height loss was noted from each
patient’s medical record. The presence of Modic changes, High-Intensity Zones
(HIZs) and vertebral endplate perforations was recorded from MRI. The
descriptive statistics of the normalized T2-weighted signal were compared using
one-way ANOVAs and a principal component analysis was proposed. MRI,
associated to normalisation of the signal intensity and principal component
analysis, offers a remarkable potential for in-vivo imaging and analysis of vertebral fractures and adjacent tissues for the
patient’s follow-up. The mean normalized MRI signal intensity of the adjacent intervertebral
disc to the vertebral fracture was found to be a bio-marker of pain,
independently of age and disc degeneration. However, the parameters
describing the distribution of the normalized signal intensity were found to
be not sensitive to the presence of low back pain, discs height loss and aging.
Further studies need to be performed to detect small abnormalities that may explain
the presence of LBP.