ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

taken from the image data, a summary of these is displayed in Table 3. Disc heights
were measured at five locations across the mid-coronal slice in both the NP and AF
stacks. The mean was taken for both the prior-to-loading and loaded states and the
change in disc height is given relative to the IVD height in the prior-to-loading image.
(a) (b)
(c)
Figure 4 – MR images using the AF scan: (a)coronal slice, preloaded; (b) coronal slice, loaded; (c)
sagittal slice, preloaded; (d) sagittal slice, loaded.
4.2 Loading Results and Comparison with Model
The results for the compression of the disc in the MRI test and the FE model are
presented in Table 3.
Change in disc
height (%)
Change in disc
width (%)
Change in NP
width (%)
MRI test -24 +11.0 +5.6
FE model -27 +3.3 +5.4
Table 3 – results for experimental and computational deformations.
5. DISCUSSION
(d)
Reduction in disc height
Radial bulge at outer
AF
The MRI sequences developed captured the internal structures of the disc soft tissues to
levels of detail not previously published. Features such as individual lamellae were
distinguishable, providing an increased level of detail of intact specimens. Images from
scans of loaded specimens showed the deformation of the soft tissues, including the
change in shape of the lamellae and the NP. The ability to capture such image data will
be useful in the calibration and validation of future computational models.
The MRI tests completed here did not include loading data for the compression of the
specimen. Future work will include an in vitro study to analyse the compression loads