独自の画像処理を加えた腰椎部3D-MR Myelographyの有用性（続報）

Usefulness of Lumbar 3D-MR Myelography Processed by an Original Image Processing Method (Sequel)

　われわれは，腰椎3D-MR myelography(3D-MRM)に独自の画像処理を加え神経根の描出を試みてきた中で，神経根遠位部病変が多いことに気付いた．そこで，当院で腰椎MRIを行った患者104人を症状とMRI所見から分類し，その内「下肢症状があり責任病巣を指摘できなかった14例」について3D-MRMを追加して検討した．14例中10例(71.4％)において，独自に画像処理を加えた3D-MRMで責任病巣として矛盾しない所見を指摘でき，それらは全例神経根遠位部病変であった．このことは，通常の腰椎MRIに3D-MRMを追加することで，従来の方法では診断が困難であった神経根遠位部病変の診断率が向上し，従来の報告よりfar-out syndromeや外側型椎間板ヘルニアが多く見つかる可能性を示唆している．

　We previously reported visualization of the involved roots in the lumbar spine, especially in the distal portion of the roots, by 3D-MR myelography (3D-MRM) performed by our original image processing method.　In the course of the study, we found many more foraminal and extra-foraminal lesions than we had found in the past.　The cases of 104 patients examined by lumbar MRI were reviewed.

　The group of cases in which the lesions responsible for the patient's leg symptoms could not be detected on lumbar MRI scans were reviewed.

　The cause of the symptoms could not be identified in 14 cases by conventional lumbar MRI, but it was detected in 10 (71.4%) of them by the 3D-MRM we devised.

　The distal portion of the roots was involved in 10 cases.

　Adding 3D-MRM to lumbar MRI is a useful means of improving the diagnosis of lumbar lesions, and more distal lesions of the lumbar roots will be found than we expected based on reports.