Radiography
Findings
The plain abdominal radiograph is usually the key to the diagnosis. In axial torsion, the image may show a markedly distended loop of large bowel with its long axis extending from the right lower quadrant to the epigastrium or left upper quadrant, the most common site to which the cecum is displaced (see Image below and Image 1 in Multimedia). Depending on the initial bowel position and the length of mobile right colon, the distended cecum may be seen anywhere in the abdomen.
Plain supine abdominal radiograph on an 81-year-old man presenting with abdominal pain and vomiting. The radiograph shows a markedly distended loop of bowel 15-cm in diameter with its axis running from the right lower quadrant to the mid abdomen. This loop of bowel represent a twisted cecum with the caput cecum directed medially (arrows). The haustra within the cecum (C) are effaced. Note the proximal dilated loop of small bowel. The distal colon shows little if any air. At surgery a cecal volvulus was confirmed.
Despite the varying positions of the distended cecum, the plain radiographic features of a cecal volvulus are characteristic, and the caput cecum can typically be identified (see first Image below and Image 2 in Multimedia). The colonic haustral pattern is generally maintained, although some effacement may be present if superimposed ischemia is present. When shorter segments of the colon and cecum are involved, the distended cecum may be found in the normal location (see second Image below and Image 3 in Multimedia).
This 53-year-old woman presented with clinical features of intestinal obstruction. This plain supine radiograph was performed on the day of admission. It shows a large air-filled viscus (15 cm in diameter), with the axis running from the mid abdomen to the left hypochondrium. No haustra are seen in the air-filled viscus (short arrow). Note that the right iliac fossa is empty (long arrow), but formed feces intermingled with air are noted in part of the ascending colon. The air can be traced up to the rectum. At this stage, no firm radiologic diagnosis was entertained, although the working clinical diagnosis was partial bowel obstruction.
This plain supine radiograph was obtained 24 hours after the radiograph in Image above. The position of the air filled viscus has changed and suggests that the air-filled viscus is mobile. The viscus now looks much more like a cecum. The caput cecum is directed toward the right iliac fossa. The twist is outlined by air (arrows).
In most patients, obstruction is almost complete; thus, the distal colon is usually empty and the small bowel is frequently distended. Occasionally, a long-axis torsion may be associated with signs of incomplete obstruction. Rarely, small-bowel loops are identified to the right of the distended cecum and ascending colon. The ileocecal valve may possibly be identified, and on occasion, the point of torsion may be outlined by gas, as an area of cone-like narrowing.
In the cecal bascule form of volvulus, the distended air-filled cecum is located more centrally. With this variant, the ileum can passively twist with the cecum, and small bowel is not obstructed. If the appendix is filled with gas and in an unusual location attached to a distended cecum, the diagnosis can be made readily.
Single-contrast barium enema examination is generally adequate for the evaluation of cecal volvulus. A double-contrast barium enema study does not confer any significant advantage, because no fine detail is necessary to make the diagnosis. The administration of glucagon is often necessary because patients may have considerable colonic spasm and find it difficult to retain the contrast agent.
The barium enema study shows a nondilated distal colon to the point of twist (see Images below and Images 4-7 in Multimedia). If the obstruction is not complete, some barium may trickle past the site of obstruction, and the twist may be visualized in more detail. If the twist occurs along the transverse axis, the obstruction appears relatively smooth, and no spiral twist is usually seen. In a cecal bascule, a rounded termination of the barium column may be seen. This, when seen near a distended gas-filled viscus, should alert the radiologist to the diagnosis of a volvulus.
Image from the unprepared barium enema examination in the same patient as in Images 2-3 in Multimedia was obtained 12 hours after the plain radiograph in Image 2 in Multimedia. The figure shows a nondilated colon. The barium-filled colon can be traced back to the right iliac fossa where there is a bird-beak cutoff (solid arrow). The dilated cecum lies in the epigastrium where there is an air fluid level (open arrow). Note that the barium has not entered the cecum.
Right oblique image from a barium enema examination in the same patient as in Images 2-4 in Multimedia shows a bird-beak appearance (arrow). At surgery, a cecal volvulus was confirmed.
A plain abdominal radiograph of 48years old lady showing a massively distended and medially displaced proximal ascending colon and cecum. The cecal pole is now lying in the left upper abdominal quadrant (C). At least two or three haustrations are seen in the distended large bowel consistent with cecal volvulus. No air fluids level has been demonstrated in this case. A single contrast barium study of the same patient showing free barium flow through the sigmoid colon in to the mid ascending colon. The proximal ascending colon and the cecum are void of barium due to obstruction at the level of the mid ascending colon.
A post evacuation film in the same patient as in Image 6 in Multimedia with showing a medially pointed end column of the barium (beak sign) in the mid ascending colon. Distally the large bowel is distended with gas and representing the cecal volvulus.
As little barium as possible should be allowed to flow proximal to the site of obstruction because flooding the bowel proximal to the obstruction site might precipitate a complete obstruction. When the barium enema is administered, overdistention should also be avoided because this can lead to perforation. An attempt should always be made to reduce the volvulus. This reduction may be achieved during colonic filling by barium, but reduction occasionally occurs during barium evacuation. With an intermittent volvulus, the barium enema results may be normal, but a postevacuation radiograph may reveal the twist.18,12
Degree of Confidence
Plain radiographic findings can be diagnostic of a cecal volvulus in most patients. In others, the findings on the plain images only suggest the diagnosis, and barium enema examination is necessary to confirm the diagnosis.
False Positives/Negatives
Rarely, the dilated displaced cecum and ascending colon in the left upper quadrant may be confused with a normal or abnormally distended stomach. A redundant looplike cecal volvulus may be confused with a sigmoid volvulus. In the presence of a double obstruction of the colon (left colon obstruction associated with a cecal volvulus), evaluation of the right colon may not be possible, and the diagnosis of volvulus must be based on plain radiographic findings alone.
Computed Tomography
Findings
CT can demonstrate a mechanical intestinal obstruction, and it can be used to differentiate between mechanical obstruction and adynamic ileus. CT scans show the site of obstruction and its severity. A volvulus or strangulation generally causes a closed-loop obstruction, and CT characteristically demonstrates a U-shaped distended bowel segment and signs of ischemia. These signs include mural thickening, infiltration of the mesenteric fat, and pneumatosis intestinalis. In the presence of a cecal or sigmoid volvulus, a whirl sign may be apparent because of a tight torsion of the mesentery that is caused by a twist between the afferent and efferent loops.3,4,5
Degree of Confidence
Several studies have shown the superiority of CT compared with plain abdominal radiography in the diagnosis of intestinal obstruction. However, the use of CT remains controversial. The present consensus is that abdominal CT should be performed in the presence of mechanical intestinal obstruction when the plain radiographic and clinical examination findings are inconclusive, especially in patients in whom the identification of the cause of obstruction may affect treatment.
The whirl sign on CT scan is not specific for cecal volvulus and may also occur in other types of volvulus, including sigmoid volvulus.3
False Positives/Negatives
The detection of a transitional zone between the dilated proximal bowel loops and collapsed distal loops distal to the obstructed site is important in diagnosing bowel obstruction on CT scans. However, a false-negative diagnosis may occur in a mixed type of ileus or in a mild partial obstruction. A false-positive diagnosis of intestinal obstruction may be made when a distended air-filled right colon is seen in the presence of a collapsed left colon.
Ultrasonography
Findings
Ultrasonography is usually the first modality used in the emergency department to investigate an acute abdomen. Cecal volvulus is usually associated with a small-bowel obstruction. The small-bowel loops are distended with fluid, and to-and-fro peristalsis is often visible. Cecal volvulus may be depicted as a grossly distended fluid-filled cecum at a lead point of small-bowel obstruction, but the appearances are generally nonspecific.6
Degree of Confidence
Ultrasonograms may suggest a diagnosis or indicate a more appropriate investigation for diagnosis. However, sonography is not a sensitive technique in the workup of a cecal volvulus.
More on Cecal Volvulus |
| Overview: Cecal Volvulus |
 Imaging: Cecal Volvulus |
| Follow-up: Cecal Volvulus |
| Multimedia: Cecal Volvulus |
| References |
| Further Reading |
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References
Perret RS, Kunberger LE. Case 4: Cecal volvulus. AJR Am J Roentgenol. Sep 1998;171(3):855, 859, 860. [Medline].
Hashimoto Y, Shigemoto S, Nakashima A, Murakami Y, Sueda T. Successful preoperative diagnosis of a rare bowel obstruction: cecal volvulus. J Gastrointest Surg. Jan 2008;12(1):202-4. [Medline].
Frank AJ, Goffner LB, Fruauff AA. Cecal volvulus: the CT whirl sign. Abdom Imaging. 1993;18(3):288-9. [Medline].
Hoeffel C, Crema MD, Belkacem A, Azizi L, Lewin M, Arrivé L. Multi-detector row CT: spectrum of diseases involving the ileocecal area. Radiographics. Sep-Oct 2006;26(5):1373-90. [Medline].
Delabrousse E, Sarliève P, Sailley N, Aubry S, Kastler BA. Cecal volvulus: CT findings and correlation with pathophysiology. Emerg Radiol. Nov 2007;14(6):411-5. [Medline].
Yeh WC, Wang HP, Chen C. Preoperative sonographic diagnosis of midgut malrotation with volvulus in adults: the "whirlpool" sign. J Clin Ultrasound. Jun 1999;27(5):279-83. [Medline].
Ruiz-Tovar J, Calero García P, Morales Castiñeiras V, Martínez Molina E. [Caecal volvulus: presentation of 18 cases and review of literature]. Cir Esp. Feb 2009;85(2):110-3. [Medline].
Wolfer J A, Beaton, L E, Anson B J. Volvulus of the cecum: Anatomical factors in its etiology. Surg Gynecol. Obstet. 1942;74:882.
Rivo, M., Farrell, G.E., Schauffer, I. A. The association of volvulus of the cecum and ascending colon with obstructive colonic lesions. Am. J. Roentgenol. 1957;78:587-590.
Torreggiani WC, Brenner C, Micallef M. Case report: Caecal volvulus in association with a mesenteric dermoid. Clin Radiol. May 2001;56(5):430-2. [Medline].
Hogan BA, Brown CJ, Brown JA. Cecal volvulus in pregnancy: report of a case and review of the safety and utility of medical diagnostic imaging in the assessment of the acute abdomen during pregnancy. Emerg Radiol. Mar 2008;15(2):127-131. [Medline].
Rabin MS, Richter IA. Caecal bascule--a potential clinical and radiological pitfall. Case reports. S Afr Med J. Aug 5 1978;54(6):242-4. [Medline].
Takada K, Hamada Y, Sato M, Fujii Y, Teraguchi M, Kaneko K. Cecal volvulus in children with mental disability. Pediatr Surg Int. Oct 2007;23(10):1011-4. [Medline].
Ramirez R, Chaumoître K, Michel F, Sabiani F, Merrot T. [Intestinal obstruction in children due to isolated intestinal malrotation. Report of 11 cases]. Arch Pediatr. Feb 2009;16(2):99-105. [Medline].
Hsu SD, Yu JC, Chou SJ, Hsieh HF, Chang TH, Liu YC. Midgut volvulus in an adult with congenital malrotation. Am J Surg. Mar 18 2008;[Epub ahead of print]. [Medline].
Yoo SJ, Park KW, Cho SY. Definitive diagnosis of intestinal volvulus in utero. Ultrasound Obstet Gynecol. Mar 1999;13(3):200-3. [Medline].
Moore CJ, Corl FM, Fishman EK. CT of cecal volvulus: unraveling the image. AJR Am J Roentgenol. Jul 2001;177(1):95-8. [Medline].
Green P, Swischuk LE, Hernandez JA. Delayed presentation of malrotation and midgut volvulus: imaging findings. Review. Emerg Radiol. Nov 2007;14(6):379-82. [Medline].
Further Reading
Related eMedicine topics
Volvulus, Sigmoid and Cecal
Colonoscopy
Obstruction, Large Bowel
Diverticulitis
Colonic Obstruction
Colon, Diverticulitis
Sigmoid Volvulus
Keywords
cecal volvulus, torsion of the ascending colon, closed-loop obstruction of the ascending colon and cecum, axial torsion, cecal bascule
