多発性硬化症が疑われる患者に対する頸部脊髄のMR画像診断は十分か？

Lesions in the spinal cord (SC) can be found in up to 83% of patients with multiple sclerosis (MS). As they are mainly located in the cervical segment, many centers exclude the thoracic part from SC imaging. The aim of our study was to quantify the decrease in sensitivity resulting from this approach.

MR images (3T) of 543 consecutive patients with clinically isolated syndrome (CIS) (n: 37) and MS (n: 506) were analyzed retrospectively. Lesions were segmented semi-automatically on axial T2-weighted images of the whole SC using BrainSeg3D. The volume of lesions was related to vertebral levels.

Altogether 1782 lesions (CIS: 19; MS: 1763) were found in 409 patients. 70% of the lesion volume was located in the SC above the 3rd thoracic vertebral body, in a segment that is commonly covered by an isolated examination of the cervical SC. However, 26 patients (6%) showed lesions exclusively below the 3rd thoracic vertebral body, thus 94% of all patients with SC lesions could be detected with isolated MR imaging of the cervical SC.

Though the majority of lesions can be detected in an isolated examination of the upper part of the SC, some patients showed lesions exclusively below the 3rd thoracic vertebral body. We recommend routine scanning of the whole SC in suspected MS.