図３と図４の↑，図９と図１０でも石灰化像（白矢印）を認め，図２で盲端になるので図３の1（↑）から尾側へ追跡すると，図１３で盲腸（C）に連続するので，1〜13は虫垂である．外径6mm以上に腫大し，壁は造影効果を受け，図２〜図４で軽度だが脂肪組織の濃度上昇（△）を認め急性虫垂炎である．TI：回腸末端．手術および病理所見：gangrenous appendicitis．

参考症例（急性虫垂炎）：49歳女性．前日に心窩部痛が出現し，次第に下腹部に移行し嘔気を伴うようになった．体温：37.3℃，下腹部全体に圧痛と反跳痛がある．
図１０の1が虫垂根部で，図２の15までは1cm大に腫大した虫垂で，壁は良好に造影され，周囲脂肪組織の濃度上昇を認め，急性虫垂炎である．TI：回腸末端．手術および病理所見（図A）：gangrenous appendicitis．

文献考察：CTを活用すればnegative appendectomyを2％まで減らせる．
Am J Surg. 2004 Dec;188(6):748-54.
Are negative appendectomies still acceptable?
Jones K, Pena AA, Dunn EL, Nadalo L, Mangram AJ.

BACKGROUND: The goal was to ascertain if there was a significant change in the negative appendectomy (NA) rate in our community hospital with the increased use of computed tomography (CT). METHODS: This was a retrospective chart review of all appendectomies for acute disease performed at our institution from January 2000 to December 2002. There is no established protocol; therefore, CT scans were performed at the discretion of the involved physicians. The results of the physical exams, CT scans and pathology were recorded. RESULTS: Three hundred eighty-nine appendectomies were performed for appendicitis. There was a progressive increase in the use of CT: 52% in 2000, 74% in 2001, and 86% in 2002. There was also a decrease in the NA rate over the 3 years: 17% in 2000, 9% in 2001 and 2% in 2002. The perforated appendicitis rate decreased from 25% in 2000 to 9% in 2002. CONCLUSION: The appropriate utilization of CT scan as an aid in the diagnosis of acute appendicitis should decrease the NA rate to 2%.PMID: 15619494