盲腸（C）は図５で盲端になり，図１のTIが回腸末端の起始部で，尾側へ下行する．図３の１が虫垂根部で，図１０の８まで下行し盲端になる．1cm大に腫大し（目盛りは図１２の右縁），壁はやや強く造影され，図５で周囲脂肪組織の濃度上昇（△）を，図６で後腹膜筋膜の肥厚（▲）を認め急性虫垂炎である．抗生物質投与で保存的に治癒した．

参考症例（5mmスライス，急性虫垂炎）：72歳男性．2日前から右下腹部痛と発熱が続いている．近医受診し，浣腸に対する反応便がないため紹介来院した．体温：38.0℃，右下腹部に圧痛，反跳痛と軽度の筋性防御を認めた．
盲腸（C）は図１１までで，回腸末端（ＴＩ）は図４から始まるが，珍しく頭側へ上行する．図８の１〜図５の４は虫垂であり，1cm以上に腫大し，壁は強く造影され，周囲脂肪組織の濃度上昇（△）を認め典型的な急性虫垂炎である．手術・病理所見：phlegmonous appendicitis．

文献考察：小児の急性虫垂炎でCTを活用することにより穿孔例は35.4%→15.5%，negative appendectomyは14.7%→4.1%に減少した．
Pediatrics. 2002 Dec;110(6):1088-93.
Effect of an imaging protocol on clinical outcomes among pediatric patients with appendicitis.
Pena BM, Taylor GA, Fishman SJ, Mandl KD.

OBJECTIVE: In 1998, we implemented a clinical imaging protocol in which children with suspected appendicitis underwent ultrasonography (US) followed by computed tomography (CT). We sought to determine the impact of the US-CT protocol on changes in perforation and negative appendectomy rates. METHODS: Children with unequivocal presentations for appendicitis went to the operating room without entering the imaging protocol. Using a modified time series design, we analyzed a prospective and retrospective cohort of consecutive patients who were admitted from the emergency department for suspected appendicitis. The perforation and negative appendectomy rates were computed for the periods before and after implementation of the imaging protocol and adjustment for time trends was made. RESULTS: A total of 1338 children were identified. Eight hundred ten (60.5%) children had equivocal clinical findings. A total of 920 patients were admitted for suspected appendicitis before the protocol was implemented; 526 (57.2%) of the 920 children had appendicitis, and 186 (35.4%) of them had perforation. A total of 91 (14.7%) of 617 had negative appendectomies. After the protocol was implemented, 418 patients were admitted for suspected appendicitis; 328 (78.5%) had appendicitis with 51 (15.5%) perforated. There were 14 (4.1%) of 342 cases of negative appendectomies. After implementation of the imaging protocol, the perforation rate decreased from 35.4% to 15.5%, and the negative appendectomy rate decreased from 14.7% to 4.1%. After secular time trends were adjusted for, the imaging protocol continued to have a strong association with a reduction in perforation rate and negative appendectomy rate. CONCLUSION: The implementation of an imaging protocol using US and CT resulted in a marked decrease in the perforation and negative appendectomy rates in children with suspected appendicitis.PMID: 12456904