腸結核のX線診断―鑑別診断を中心に

Enteric Tuberculosis: Focused on Differential Diagnosis

要旨　腸結核のX線像は基本的には，①個々の潰瘍の形態（代表的なものは帯状潰瘍），②潰瘍搬痕を伴う粘膜萎縮帯，③変形（大腸の場合はhaustraの消失，腸管長軸方向への短縮，狭窄，憩室様変形，タッシュ様変形など）の3つに要約できる．鑑別すべき主な疾患としてはCrohn病，潰瘍性大腸炎，虚血性腸炎が挙げられるが，鑑別診断上参考になる事項としては，①潰瘍性病変の方向性（腸結核では横軸方向，Crohn病や虚血性腸炎では縦軸要素の潰瘍），②病変の罹患部位（小腸の場合，腸結核では腸間膜付着対側，Crohn病では腸間膜付着側に潰瘍は好発する）と共に，③画像の経時的変化の観察が挙げられる．それでもなお確診がつけられず，どのように治療すればよいかとまどう症例があり，これらの症例をどのように取り扱うかが今後の問題である．

　Radiologic features of enteric tuberculosis were summarized as follows: 1) individual ulcers (typically band-like ulcers), 2) atrophic mucosal zone with ulcer scar, 3) deformity (in case of the colon, disappearance of haustra coli, shortening of the colon in the longitudinal direction, stenosis, diverticulum-like deformity, cloverleaves-like deformity etc). Differential diagnosis should include Crohn's disease, ulcerative colitis, ischemic colitis, and clues to differential diagnosis would be 1) direction of ulcerative lesions (ulcerative lesions of intestinal tuberculosis tend to be arranged in the circumferential direction, whereas those of Crohn's disease and ischemic colitis may be disposed in the longitudinal direction), 2) location of the lesion (in case of the small intestine, lesions of intestinal tuberculosis may be located on the opposite side of mesenterial attachment, on the other hand, those of Crohn's disease may be seen on the same side of mesenterial attachment), 3) observation of chronological changes by the images.

　However, there still have been some cases which were difficult to diagnose and treat, we need to solve how to deal with above cases in the future.