Progression of lumbar disc herniations over an eight-year period in a group of adult Danes from the general population--a longitudinal MRI study using quantitative measures.

Background: A lumbar disc herniation (LDH) is a localised displacement of disc material, which may initiate changes in the disc and adjacent structures such as the nerve root and the spinal canal. Knowledge about how morphological changes in the disc relate to changes in other spinal structures might give the clinician a better understanding of the natural history and consequences of lumbar disc herniations. However, few longitudinal studies have investigated this process using reliable measures from magnetic resonance imaging (MRI).

A method for quantitative measurement of lumbar intervertebral disc structures: an intra- and inter-rater agreement and reliability study.

Background: There is a shortage of agreement studies relevant for measuring changes over time in lumbar intervertebral disc structures. The objectives of this study were: 1) to develop a method for measurement of intervertebral disc height, anterior and posterior disc material and dural sac diameter using MRI, 2) to evaluate intra- and inter-rater agreement and reliability for the measurements included, and 3) to identify factors compromising agreement.

Methods: Measurements were performed on MRIs from 16 people with and 16 without lumbar disc herniation, purposefully chosen to represent all possible disc contours among participants in a general population study cohort.