図１と図２，図２４と図２５で腹水（※）があり，拡張した小腸はgaslessで，図１８〜図２１で腸間膜の浮腫（▲）を認めるので絞扼性小腸閉塞の可能性があり，closed loopを証明すれば確定診断となる．追跡は比較的容易で，図２３のAは図１０のUで，1は図９の81で閉塞する．珍しく単純閉塞の拡張した小腸はないが，図１０と図１１で虚脱した小腸があり，closed loopを形成した絞扼性小腸閉塞と診断できる．絞扼された小腸壁は良好に造影されviableである．手術で空腸約150cmが反時計方向へ180度捻転し，虚血状態を示していたが，捻転解除で色調が改善し腸管切除は不要であった．この症例のCTではwhirl signを認めず捻転の診断は出来ない．

文献考察：”whirl sign”，小腸軸捻転の大部分にwhirl signを認めるが，逆にCTで発見されるwhirl signの大部分は軸捻転ではない.
J Comput Assist Tomogr. 2006 Jan-Feb;30(1):25-32.
Does the CT whirl sign really predict small bowel volvulus?: Experience in an oncologic population.
Gollub MJ, Yoon S, Smith LM, Moskowitz CS.

The objective of this study was to determine the sensitivity of the CT "whirl sign" for the diagnosis of small bowel volvulus in patients who present with a clinical suspicion of intestinal obstruction. Between January 2002 and September 2004, 1,493 CT scans performed in 1,213 patients suspected of having small bowel obstruction were retrospectively reviewed by one attending radiologist with gastrointestinal subspecialization and one senior radiology resident. Multislice helical CT scans were performed after oral and intravenous contrast administration. All CT scans showing a combined vessel and bowel whirl appearance were identified. Other features recorded included the number of degrees of whirl rotation, direction of rotation, presence of bowel obstruction, and signs of ischemia. Diagnoses were determined at either surgery or clinicoradiographic follow-up. Surgical follow-up was available in 174 of the 1,213 patients. There were 460 males and 753 females ranging in age from 1 to 95 years (mean 59 years). A whirl sign was found in 33 of the 1,493 CT scans by reader 1 and in 13 of the 1,493 CT scans by reader 2. In 11 patients, surgery revealed small bowel volvulus (0.9%). Reader 1 detected 7 of the 11 volvuli (sensitivity 64%, specificity 98%, positive predictive value 21%, negative predictive value 99.7%). Reader 2 detected 3 of the 11 volvuli (sensitivity 27%, specificity 99%, positive predictive value 23%, negative predictive value 99.5%). The CT scans of the four remaining patients with volvulus not initially recognized by either reader were re-reviewed and were felt to contain whirl signs. Most patients with small bowel volvulus can be identified on CT through detection of a whirl sign. However, most whirl signs detected on CT will not prove to be indicative of small bowel volvulus.PMID: 16365568