腸管感染症の画像診断

Image Diagnosis of Intestinal Tract Infection

要旨●本稿では主な急性腸管感染症であるカンピロバクター腸炎，サルモネラ腸炎，腸管出血性大腸菌腸炎，エルシニア腸炎，偽膜性腸炎，アメーバ性大腸炎，腸アニサキス症の腹部CT像と内視鏡像について述べる．腹部CT像では，腸管壁肥厚の有無・局在・程度，腸管周囲の炎症の有無・程度，リンパ節腫大の有無・程度，腹水の有無・程度，などに注目して診断する．大腸型の細菌性腸炎のCT像では，高率に右側結腸の壁肥厚がみられる．一方，内視鏡像では，罹患部位と浮腫・粘膜内出血・うろこ模様・びらん・潰瘍・偽膜の有無やその性状により腸管感染症の鑑別診断を行う．エルシニア腸炎ではPeyer板の肥厚とその上のびらんが特徴的内視鏡像である．重症の偽膜性腸炎では膜状偽膜を呈するが，この所見は偽膜を伴う重症のアメーバ性大腸炎と類似しているため注意する必要がある．両疾患における類似した内視鏡像を提示した．

　Knowing abdominal CT image characteristics and endoscopic characteristics of intestinal tract infection is useful for differential diagnosis of acute enterocolitis. We examined the abdominal CT image characteristics and endoscopic characteristics of Campylobacter enterocolitis, Salmonella enterocolitis, Yersinia enterocolitis, pseudomembranous colitis, amebic colitis, and intestinal anisakiasis, with special attention to the presence or absence of and the degree of bowel wall thickening, inflammation around the intestinal tract, lymph node swelling, and ascites. The CT image findings of patients with colonic-type bacterial enterocolitis revealed widespread thickening of the right-sided colonic wall. Endoscopic differential diagnosis of intestinal tract infection was performed by the affected area and the presence or absence of edema, intramucosal redness, scale pattern, erosion, ulcer and pseudomembrane. Typical endoscopic findings of Yersinia enterocolitis were swollen Peyer patches with erosions. The endoscopic findings of severe pseudomembranous colitis were similar to those of severe amebic colitis involving pseudomembrane. We successfully presented the endoscopic imaging of both the diseases in this paper.