General Spine

Klaus, M, FRIEDRICH, M.D.
David, Stelzeneder, M.D., Non ASSR Member
Sabine, Goed, Non ASSR Member
Goetz, H, Welsch, M.D., Non ASSR Member
Tatjana, Paternostro-Sluga, M.D., Non ASSR Member
Siegfried, Trattnig, M.D., Non ASSR Member

Paper/Non-Mentor

Purpose

To investigate the relationship between T2 relaxation time measurements and standardized morphological scoring of disc degeneration in patients with low back pain.

Methods & Materials

Fifty-three patients (mean age, 39 years; age range, 15-64 years) with low back pain had 3T MR imaging of the lumbar spine including the following sequences: T1-FSE sagittal, T2-FSE sagittal and axial, multiecho-spinecho sagittal. All disc were scored according to the classification introduced by Pfirrmann et al.. The multiecho-spinecho sequence was used to generate T2 maps. Regions of interest (ROIs) were placed within the outermost 20% of the disc on two adjacent slices to measure T2 values in the anterior and posterior annulus fibrosus and within the space in between, which was defined as the nucleus pulposus. The ratio between annulus fibrosus and nucleus puplosus (T2 A-N-index) was calculated as follows: T2 A-N-index = T2 (annulus fibrosus) / T2 (nucleus pulposus).

Results

The 265 discs were scored as follows: I, 6 discs (2.3%); II, 153 discs (57.7%), III, 81 discs (30,6%), and IV, 25 discs (9.4%). The mean T2 value of the annulus fibrosus was 53+/-16ms ; the mean T2 value of the nucleus pulposus was 108+/-46ms. The following T2 A-N-index values were calculated for the Pfirrmann groups I to IV: I, 0.19+/-0.07; II, 0.47+/-0.14; III, 0.61+/-0.16; IV, 0.81+/-0.19 (image 1). The differences between the groups were highly significant (p<0.001).

Conclusion

MR T2 mapping of the intervertebral discs showed good differentiation between annulus fibrosus and nucleus pulposus in morphological intact discs, which decreases with increasing degeneration of the disc resulting in an increase of the T2 A-N-index.

References/Financial Disclosures

Magnetic resonance classification of lumbar intervertebral disc degeneration.
Pfirrmann CW, Metzdorf A, Zanetti M, Hodler J, Boos N.
Spine (Phila Pa 1976). 2001 Sep 1;26(17):1873-8.