T1 mapping using MP2RAGE in degenerative cervical myelopathy: a longitudinal study.

BACKGROUND AND PURPOSE

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord (SC) dysfunction. In routine clinical practice, SC changes are well depicted using conventional MRI, especially T2-weighted imaging. However, this modality usually fails to provide satisfactory clinico-radiological correlations. In this context we assessed the potential value of quantitative changes measured with a T1 MP2RAGE sequence.

MATERIALS AND METHODS

18 patients diagnosed with chronic onset of DCM and 17 healthy controls (HC) were enrolled in the study. Clinical presentation was assessed using the modified Japanese Orthopaedic Association (mJOA) scale. Sagittal cervical SC T2-w 3D SPACE imaging and T1 MP2RAGE mapping were performed at baseline and 3-months postoperatively. Data were processed using Matlab and the SC Toolbox.

RESULTS

mJOA score increased from 13.3 ± 2.1 preoperatively to 14.4 ± 1.9 at follow-up (p = 0.027). Site of maximum compression (Cmax) was at C3-C4 cervical levels in 4 patients, C4-C5 in 8 patients, C5-C6 in 5 patients and C6-C7 in 1 patient. SC compression was multi-level in 7 patients and single-level in 11 patients. T2-w hyperintensity was present in 15 patients. Mean SC T1 values in the whole SC in the DCM group at baseline showed significant difference as compared to mean SC T1 values in HC group (962.2 ± 62 vs. 924.9 ± 34 ms, respectively (p < 0.0001)) but no differences could be observed between baseline and 3-month follow-up (962.4 ± 59 ms (p = 0.86)). Z-scores at baseline were - 0.05 ± 1 for mild, 1.2 ± 1.9 for moderate and 2.5 ± 1.2 for severe. Mean baseline and 3-month follow-up SC T1 values were weakly but significantly correlated to preoperative (R = 0.33 (p = 0.013) and postoperative mJOA (R = 0.29 (p = 0.024). Baseline T1 value at C2 level was significantly correlated with mJOA at 3-month follow-up (p = 0.048).

CONCLUSIONS

T1-MP2RAGE mapping in patients with DCM demonstrated both focal and diffuse cervical SC alteration. It could thus be a biomarker for patients with DCM managed surgically.