図１で腹水のdensityが計測されているが，通常の腹水は0〜15HU，血液は30以上，50以上は血腫を示唆する．極めて重要な情報なので腹水のdensityは必ず計測するよう技師を教育する必要がある．画像が黒すぎて認識しづらいが，図２〜図７で↑は腸管外遊離ガスを示しており，図１と，図８〜図１４（Morison窩：※）では血性腹水または血腫を示しており，消化管穿孔の可能性が極めて高い．図７〜図９のPが幽門輪だから，図５〜図７のAは胃前庭部で，壁肥厚を呈し，図７〜図１１の十二指腸も壁肥厚または周囲に血腫（図９〜図１１：▲）を示しているので，胃または十二指腸，あるいは両者の穿孔を疑う．図３〜図９の白矢印は肝損傷である．次に，図１３〜図１５の△は周囲に相当量の血腫を伴っているのでextravasationであり，胃の尾側で前腹壁直下に位置し大網での活動性出血である．5時間後に腹膜刺激症状を示し手術となり，970mlの大網からの活動性出血，胃前庭部と十二指腸穿孔（図A：↑）を認め，穿孔部周囲の挫滅も強かったので切除し，図Bの再建が行われ，術後は順調に経過した．

文献考察：下記5CT所見のうち3所見以上あれば手術，1または2所見だけならDPL（筆者は4,5時間後にCT再検を勧めます）. algorithm（図）
Am J Emerg Med. 2006 Jan;24(1):19-24.
Diagnosis of bowel and mesenteric injuries in blunt abdominal trauma: a prospective study.
Menegaux F, Trésallet C, Gosgnach M, Nguyen-Thanh Q, Langeron O, Riou B.

PURPOSE: Currently, nonoperative management is the procedure of choice for solid organ injury in patients with a blunt abdominal trauma. Missed blunt bowel and mesenteric injuries (BBMIs) are possible because diagnosis is difficult. The aim of our study was to test a new algorithm for BBMI diagnosis using abdominal ultrasonography (AUS), computed tomography (CT), and diagnostic peritoneal lavage (DPL). METHODS: We reviewed cases of blunt abdominal injuries over a 10-year period, then we designed an algorithm that was prospectively tested in hemodynamically stable patients over a 2-year period. An abnormal AUS led to helical CT. When the CT showed more than 2 findings suggestive of BBMI, laparotomy was performed. In case of 1 or 2 abnormal CT findings, we performed a DPL and calculated the ratio of white blood cells (WBCs) to red blood cells (RBCs) (WBC/RBC ratio) in the lavage fluid and divided this by the WBC/RBC ratio in peripheral blood. A ratio of 1 or higher was considered positive for BBMI, and a laparotomy was immediately performed. Patients with a ratio of less than 1 were managed nonoperatively. RESULTS: In the retrospective study, 26 (1%) of 2126 patients admitted to our trauma center for blunt trauma had a BBMI, including 15 (58%) diagnosed after a median delay of 24 hours. In the prospective study, 531 patients were admitted for blunt trauma with multiple injuries, including 131 with abdominal trauma. Computed tomography was performed in 40 patients. There were 2 criteria or more of BBMI in 1 patient, 0 criteria in 27 patients (with an uneventful follow-up), and 1 or 2 criteria in 12 patients who had DPL with a median ratio of 0.82 (ranges, 0.03-9). Five patients had a ratio of 1 or higher. They underwent immediate laparotomy. In all 5 cases, BBMI was found. The 7 patients who had a ratio of less than 1 were observed in ICU and treated for extra-abdominal injuries. No BBMI injury was missed in these patients. The accuracy of the algorithm was 100% (95% confidence interval, 0.99-1.00). CONCLUSION: The proposed algorithm (based on AUS, CT, and DPL) had a high accuracy to diagnose BBMI while requiring the performance of DPL in only a few (2%) patients. PMID: 16338504
要旨：５CT所見．１）遊離ガス，２）unexplained intraperitoneal fluid（実質臓器損傷がないのに存在する腹水），３）腸管壁肥厚，４）mesenteric fat streaking（腸間膜の筋状の濃度上昇），５）腸間膜血腫．