炎症性大腸疾患の鑑別診断―X線診断の立場から

Radiological Differential Diagnosis of Inflammatory Bowel Disease with Special Reference to Colo-rectal Lesions

要旨　自験255例の炎症性大腸疾患のX線，内視鏡，生検組織検査の初回診断能をみると，それぞれ78.4％，82.7％，54.9％であった．有所見群でみるとX線診断能は84.4％となり，肉眼所見のみからではX線，内視鏡診断能はほとんど同じであった．初回生検診断能は低かった．X線の鑑別診断能を向上させるために，初回X線診断で確定診断が不能であった55例の再検討（見直し診断）を行った．その結果，大多数（85％，47/55）は診断可能となった．見直し診断には，内視鏡や，臨床情報の十分与えられた生検診断の併用が最も有用であるが，病歴や臨床症状，細菌学的検査を含めた臨床検査所見の詳細な把握，臨床経過，X線による経時的診断や小腸病変合併の有無の検討などが重要と思われた．見直し診断後の真の意味の分類困難大腸炎（狭義）は1.2％（3/255）という成績であった．

　A study was conducted regarding differential diagnosis of inflammatory bowel disease based mainly on radiological findings in 255 cases (ulcerative colitis 140, radiation colitis 46, tuberculous colitis 20, Crohn's colitis 12, ischemic colitis 7, simple ulcer or intestinal Behçet's disease 5, drug-induced colitis, diverticulitis, mucosal prolapse syndrome (solitary rectal ulcer) 4 each, amebic colitis 2, others 11 cases).

　Radiological, endoscopical, and histopathological (biopsy) diagnosis of I.B.D. at the first examination occurred 78.4%, 82.7%, and 54.9%, respectively.

　Unclassified colitis accounted for 21.6% (55/255) of the clinical cases at the initial radiological diagnosis.

　Most (52/55, 94.5%) of the cases were reclassified into one of the known inflammatory bowel diseases when clinicopathologically reviewed.

　The proportion of unclassified (indeterminated) colitis (in true sense) thus decreased to 1.2% (3/255).

　In order to increase the accuracy of radiological differential diagnosis for I.B.D., it is necessary to perform both small intestinal study and follow-up barium enema.