健常者における頚椎MRIの検討

MRI Findings in the Cervical Spine of Healthy Volunteers

　抄録：健常例117例の頚椎MRIを撮像し，椎間板輝度低下，椎間板狭小，椎間板後方突出，椎間孔狭小，黄色靱帯肥厚，突出の年代別，性別，椎間別に検討し，硬膜脊髄圧迫の頻度を検討した．椎間板輝度低下は93％に認めた．椎間板狭小は52％に認め，男性は50歳代以上，女性は20歳代より有意に狭小化し，C4/5，5/6は他椎間より有意に狭小していた．椎間板後方突出は32％に認め，40歳代より増加し，C5/6，6/7に有意に多かった．黄色靱帯の肥厚，突出は22％で50歳代以降で増加し，C5/6，6/7に有意に多い．硬膜管，脊髄圧迫は42％，脊髄圧迫は10％に認められたが，髄内高信号変化例はなかった．50歳代以上での頻度は椎間板狭小83％，椎間板膨隆54％，椎間孔狭小24％，黄色靱帯肥厚46％，硬膜・脊髄圧迫76％，脊髄圧迫24％であり，これらを念頭に置いてMRI診断を行う必要がある．

　We examined the MRI images of the cervical spine obtained in 117 normal volunteers. There were 66males and 51 females, and their age range was 7-72 years old (mean age：40 years). We evaluated the MRI images, for disc degeneration as manifested by using low signal intensity, posterior disc protrusion, narrowing of the disc space, foraminal stenosis, and hypertrophy of the ligamentum flavum. MRI equipment used was a SIGNA 1.5T machine (GE), and sagittal T2-weighted images (TR 4000ms, TE 100ms, Matrix 512×512, FOV 24cm×24cm) and axial T1-weighted images (TR 500ms, TE 10ms, Matrix 512×512, FOV 20cm×20cm) were acquired. The evidence of degeneration of the cervical spine increased linearly with age, especially from 60 years of age onward. Disc degeneration was present in 67％of the disc in men and in 50％of the discs in the females under 20 years old. Narrowing of the disc space was present in 52％, posterior disc protrusion was present in 32％, foraminal stenosis was present in 13％, and hypertrophy of ligamentum flavum was present in 22％. Compression of the dural sac was observed in 44％, but spinal cord compression was observed only in 8％. The results show that care must be exercised when for interpreting the MRI findings in patients with symptomatic disorders of the cervical spine.