T1 mapping in patients with cervical spinal canal stenosis with and without decompressive surgery: A longitudinal study.

BACKGROUND AND PURPOSE:Cervical spinal canal stenosis (cSCS) is a common cause of spinal impairment in the elderly. With conventional magnetic resonance imaging (MRI) suffering from various limitations, high-resolution single-shot T1 mapping has been proposed as a novel MRI technique in cSCS diagnosis. In this study, we investigated the effect of conservative and surgical treatment on spinal cord T1 relaxation times in cSCS. METHODS:T1-mapping was performed in 54 patients with cSCS at 3 Tesla MRI at the maximum-, above and below the stenosis. Subsequently, intraindividual T1-differences (ΔT1) intrastenosis were calculated. Twenty-four patients received follow-up scans after 6 months. RESULTS:Surgically treated patients showed higher ΔT1 at baseline (154.9 ± 81.6 vs. 95.3 ± 60.7), while absolute T1-values within the stenosis were comparable between groups (863.7 ± 89.3 milliseconds vs. 855.1 ± 62.2 milliseconds). In surgically treated patients, ΔT1 decreased inverse to stenosis severity. After 6 months, ΔT1 significantly decreased in the surgical group (154.9 ± 81.6 milliseconds to 85.7 ± 108.9 milliseconds, p = .021) and remained unchanged in conservatively treated patients. Both groups showed clinical improvement at the 6-month follow-up. CONCLUSIONS:Baseline difference of T1 relaxation time (ΔT1) might serve as a supporting marker for treatment decision and change of T1 relaxation time might reflect relief of spinal cord narrowing indicating regenerative processes. Quantitative T1-mapping represents a promising additional imaging method to indicate a surgical treatment plan and to validate treatment success.