やや拡張した上行結腸（A）は図２で閉塞する．図２と図４で上行結腸（A）と，小腸と思われる隣のSBとは内容物が違うので連結しないと解釈する．図８と図９の↑は不整に造影される腫瘤で，閉塞の責任病変と思われ，悪性腫瘍を示唆する．上行結腸（A）とその背側に存在する※は，通常のウィンドウ幅の画像では一見ガス様に見えるが，ウィンドウ幅を拡大した図１２と図１４で固形便であることが判明する．CTではこのような固形便がまれに見られることに注意してほしい．上行結腸（A）の背側の※は腸管外に漏出した糞便で，図１２と図１４の△部位が壁欠損を示しており，穿孔部位と思われる．従って，肝弯曲部大腸癌による大腸閉塞と上行結腸穿孔と診断する．図１，図３と図５の白矢印は転移病巣であろう．図６でIVCが虚脱しており，重度のhypovolemiaがある．強い脱水があると，脳と心臓に血流を増やすために腹腔内血管は攣縮を起こすといわれ，脱水が穿孔を早めた可能性がある．手術で肝弯曲部（横行結腸）癌と上行結腸穿孔を認めた．

参考文献：大腸穿孔
Abdom Imaging. 2004 Nov-Dec;29(6):658-62. Epub 2004 May 27.
Multidetector-row CT findings of colonic perforation: direct visualization of ruptured colonic wall.
Miki T, Ogata S, Uto M, Nakazono T, Urata M, Ishibe R, Shinyama S, Nakajo M.

BACKGROUND: We examined the findings of contrast-enhanced multidetector-row computed tomography (MD-CT) in patients with colonic perforation. METHODS: Abdominal contrast-enhanced MD-CT findings in six patients with colonic perforation were reviewed retrospectively. Patients (three men and three women) were 74 to 88 years old (mean age = 78 years). Colonic perforation was confirmed by surgery. CT findings were correlated with surgical and pathologic findings. RESULT: The site of colonic perforation was suggested by the following combination of CT findings: free air, dirty mass, dirty fat sign, extraluminal fluid collection, bowel wall thickening, and interruption of colonic wall. The ruptured colonic wall was directly visualized in four cases (67%). CONCLUSION: Abdominal contrast-enhanced MD-CT may improve the accuracy of diagnosis and localization of colonic perforation.PMID: 15162233