図６〜図１０で右側腹壁の肥厚（↑）は外傷部位を示し，その周辺の腹部臓器損傷に注意する必要がある．図５〜図１０で上行結腸（A）背側の後腹膜腔に濃度上昇所見（▲）を認め，上行結腸損傷を疑うべき所見である．結腸穿孔の予後は悪いので厳重な経過観察が必要であり，頻回の腹部所見の観察と，数時間ごとに腹部エコー，CT検査や炎症反応をチェックしながら早期発見に最大の努力をすべきである．その後2日間で腹部は次第に膨満し，発熱が出現し敗血症の状態を呈してきた．図１３〜図２０は2日後のCTで，右側腎周囲の後腹膜腔と腹腔内に多数の遊離ガス（△）を認め上行結腸（A）穿孔を強く示唆する．D：十二指腸．手術で上行結腸の後腹膜腔への穿孔を認め，広範囲の汚染を伴っていた．消化管穿孔のCT診断においては上記の些細な所見にも注目し経時的に検査を進めていくことが大事である．

参考症例（上行結腸穿孔）：40歳男性．助手席に乗車中に追突し胸腹部を打撲した．体温：37.0℃，腹部は右側に圧痛，反跳痛と筋性防御を認める．
図１〜図８で上行結腸背側に濃度上昇（高濃度の部分は血腫：▲）を認め，上記症例同様上行結腸損傷を疑う．図６と図７の↑は腸管外遊離ガスの可能性が高く，図６の△は壁断裂で穿孔部位を示しているのであろう．腹膜刺激症状があるので手術となり，上行結腸に穿孔を認めた．

文献考察：消化管穿孔のCT検査に経口的造影剤投与は不要である．
１）J Trauma. 2004 Feb;56(2):314-22.
Computed tomographic scanning without oral contrast solution for blunt bowel and mesenteric injuries in abdominal trauma.
Allen TL, Mueller MT, Bonk RT, Harker CP, Duffy OH, Stevens MH.

BACKGROUND: Computed tomographic (CT) scanning using intravenous and oral contrast material has traditionally been advocated for the evaluation of intra-abdominal injury, including blunt bowel and mesenteric injuries (BBMIs). The necessity of oral contrast in detecting these injuries has recently been called into question. The purpose of this study was to determine the sensitivity and specificity of CT scanning without oral contrast for BBMIs. METHODS: We prospectively enrolled 500 consecutive blunt trauma patients who received CT imaging and interpretation (CT-Read1) of the abdomen from July 2000 to November 2001. All patients were imaged without oral contrast, but with intravenous contrast. CT images were reviewed within 24 hours of admission by a research radiologist (CT-Read2) blinded to CT-Read1. For study purposes, true BBMI was determined to be present if either laparotomy or autopsy identified bowel or mesenteric injury, or both CT-Read2 and the hospital discharge summary described bowel or mesenteric injury. Three-month telephone follow-up was also completed. RESULTS: CT-Read1 detected 19 of 20 bowel and mesenteric injuries. CT-Read1 missed one duodenal perforation. There were two patients with false-positive interpretations of CT-Read1 for bowel injury. The sensitivity and specificity of CT imaging for the detection of BBMIs were 95.0% and 99.6%, respectively. CONCLUSION: CT imaging of the abdomen without oral contrast for detection of BBMIs compares favorably with CT imaging using oral contrast.　PMID: 14960973

２）Arch Surg. 1999 Jun;134(6):622-6; discussion 626-7.
Oral contrast solution and computed tomography for blunt abdominal trauma: a randomized study.
Stafford RE, McGonigal MD, Weigelt JA, Johnson TJ.

HYPOTHESIS: Oral contrast solution (OC) is unnecessary in the acute computed tomographic (CT) evaluation of the patient with blunt abdominal trauma. DESIGN: Randomized controlled clinical trial. SETTING: Level I trauma center at a university-affiliated teaching hospital. PATIENTS: Five hundred adult patients sustaining blunt abdominal trauma and requiring urgent resuscitation and CT evaluation of the abdomen were eligible for the study. Those patients who were younger than 18 years, pregnant, or in police custody were excluded. One hundred six patients were excluded from the analysis (15 for inappropriate enrollment, 9 because a CT scan had not been performed, 1 owing to inability to accept a nasogastric tube, and 81 owing to missing or incomplete records). Three hundred ninety-four patients with an average age of 36 years, an average Revised Trauma Score of 10, and an average Glasgow Coma Scale score of 12 are included in the analysis. INTERVENTIONS: Patients were randomized via computer-generated assignment to 1 of 2 groups either receiving OC or not receiving OC (no OC) after placement of a nasogastric tube. All patients received intravenous contrast solution and then underwent helical CT scan of the abdomen and pelvis using the GE HiSpeed Advantage CT scanner (GE Medical Systems, Milwaukee, Wis). MAIN OUTCOME MEASURES: Abnormal CT results, need for laparotomy, missed gastrointestinal tract and solid organ injuries, nausea, and vomiting. RESULTS: There were 199 patients in the OC group and 195 patients in the no OC group. Vomiting occurred in 12.9% of patients and the incidence was not different between groups. One hundred five abnormal scans (50 OC and 55 no OC) were obtained and 33 patients with abnormal scans (19 OC and 14 no OC) underwent laparotomy. There was 1 nontherapeutic laparotomy in each group. There was 1 missed small-bowel injury in the OC group (sensitivity, 86%) and no missed small-bowel injuries in the no OC group (sensitivity, 100%). Six bowel injuries were identified at laparotomy in the OC group. Two of the injuries were perforations without contrast extravasation but with pneumoperitoneum in 1. Three bowel injuries were identified in the no OC group, none of which were perforations. Seven of the 9 patients with bowel injury at laparotomy had associated intra-abdominal injury. Specificity for solid organ injury was 94% in the OC group and 57.1% in the no OC group. Sensitivity for solid organ injury was 84.2% in the OC group and 88.9% in the no OC group. The average time to abdominal CT scanning after placement of a nasogastric tube was 39.02+/-18.73 minutes in the no OC group and 45.92+/-24.17 minutes in the OC group (P= .008). CONCLUSION: The addition of OC to the acute CT protocol for the evaluation of the patient with blunt abdominal trauma is unnecessary and delays time to CT scanning. PMID: 10367871