DOI: 10.1148/radiol.2443041285
(Radiology 2007;244:919-922.)
© RSNA, 2007
Case 120: Ischemic Colitis Limited to the Cecum1
Marc A. Mancuso, MD ,
Yvonne Y. Cheung, MD ,
Anne M. Silas, MD ,
Jocelyn D. Chertoff, MD and
Kevin W. Dickey, MD
1 From the Department of Radiology, Dartmouth-Hitchcock Medical Center, One Medical Center Dr, Lebanon, NH 03756. Received July 26, 2004; revision requested September 29; revision received December 20; final version accepted January 17, 2005.
Correspondence: Address correspondence to M.A.M. (e-mail: marc.mancuso{at}tch.harvard.edu).
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HISTORY
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A 75-year-old woman presented to the emergency department and reported new onset of diffuse abdominal cramps, nausea, fever, and chills. The patient had an extensive history of cardiac procedures, including placement of an aortic valve prosthesis and cardiac catheterization performed 10 days prior to the current admission. Her medical history was also notable for long-standing celiac sprue and acute appendicitis at age 13 that was treated with appendectomy. The patient denied recent foreign travel. Physical examination revealed mild right lower quadrant tenderness without signs of peritonitis and a fever of 100.4°F (38.0°C). White blood cell count, including absolute neutrophil count, was normal. Computed tomographic (CT) examination of the abdomen and pelvis was performed with only intravenous contrast material (100 mL of iohexol, Omnipaque 300; Amersham Health, Princeton, NJ) on day 1 and with both oral (15 g of diatrizoate sodium in 24 oz of water; Hypaque Sodium, Amersham Health) and intravenous contrast material on day 2.
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IMAGING FINDINGS
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The CT scout view of the abdomen revealed gas-filled small-bowel loops displaced from the right lower quadrant, sternotomy wires, and an aortic valve prosthesis (Fig 1a). A cecal "target sign" enhancement pattern, which indicated submucosal edema (Fig 1b), was evident. The remainder of the bowel appeared normal, without evidence of obstruction or pneumoperitoneum. A small amount of free fluid was present in the pelvis, and there was a small unenhanced fluid collection adjacent to the right common femoral artery (Figs 1c, 2b). CT was performed with oral and intravenous contrast material the day after admission and again revealed persistent pelvic ascites and a markedly thickened cecum (Fig 2a) that displaced normal small-bowel loops from the right lower quadrant of the abdomen (Fig 2b).
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Figure 1a: (a) Coronal CT scout view of the abdomen and pelvis shows gas-filled small-bowel loops (black arrows) displaced from the right lower quadrant. An aortic valve prosthesis and a sternotomy wire (white arrow) are also visible. (b, c) Contrast material–enhanced transverse CT scans obtained at the level of the (b) midsacrum and (c) femoral heads. In b, a thickened, homogeneously hypoattenuating cecal wall with a target sign enhancement pattern (arrows) is visible. In c, a nonenhancing fluid collection (black arrow) around the right common femoral artery and ascites (white arrows) can be seen.
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Figure 1b: (a) Coronal CT scout view of the abdomen and pelvis shows gas-filled small-bowel loops (black arrows) displaced from the right lower quadrant. An aortic valve prosthesis and a sternotomy wire (white arrow) are also visible. (b, c) Contrast material–enhanced transverse CT scans obtained at the level of the (b) midsacrum and (c) femoral heads. In b, a thickened, homogeneously hypoattenuating cecal wall with a target sign enhancement pattern (arrows) is visible. In c, a nonenhancing fluid collection (black arrow) around the right common femoral artery and ascites (white arrows) can be seen.
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Figure 1c: (a) Coronal CT scout view of the abdomen and pelvis shows gas-filled small-bowel loops (black arrows) displaced from the right lower quadrant. An aortic valve prosthesis and a sternotomy wire (white arrow) are also visible. (b, c) Contrast material–enhanced transverse CT scans obtained at the level of the (b) midsacrum and (c) femoral heads. In b, a thickened, homogeneously hypoattenuating cecal wall with a target sign enhancement pattern (arrows) is visible. In c, a nonenhancing fluid collection (black arrow) around the right common femoral artery and ascites (white arrows) can be seen.
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Figure 2a: (a) Transverse contrast-enhanced CT scan obtained the day after admission at the level of the midsacrum shows a thickened cecal wall (white arrows) and pelvic ascites (black arrows). (b) Reformatted coronal oblique CT scan of the right lower quadrant of the abdomen shows bowel wall thickening (black arrows) limited to the cecum and a fluid collection (white arrows) adjacent to the right common femoral artery.
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Figure 2b: (a) Transverse contrast-enhanced CT scan obtained the day after admission at the level of the midsacrum shows a thickened cecal wall (white arrows) and pelvic ascites (black arrows). (b) Reformatted coronal oblique CT scan of the right lower quadrant of the abdomen shows bowel wall thickening (black arrows) limited to the cecum and a fluid collection (white arrows) adjacent to the right common femoral artery.
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DISCUSSION
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Differential considerations included inflammatory, infectious, and ischemic colitides, as well as an infiltrative mass. Lymphoma was considered because of its increased incidence in patients with sprue (1); however, the absence of lymphadenopathy and the acute onset of symptoms argued against this diagnosis. Cytomegalovirus colitis and typhlitis may display a similar radiographic appearance (2); however, these diagnoses were considered less likely because there was no evidence of immunodeficiency in this patient. Colonic ameboma, a rare complication of amebic colitis that occurs most often in the cecum, was also considered unlikely because this patient had no history of travel to an endemic area (3). Inflammatory causes, such as ulcerative colitis and Crohn disease, were thought to be less likely given the acute onset of symptoms, the patient's age, the focal nature of the findings, and the absence of inflammatory changes in the pericecal fat.
The acute onset of crampy abdominal pain in an elderly patient with a history of cardiac surgery (placement of an aortic valve prosthesis and right-sided groin hematoma from recent cardiac catheterization) favored a diagnosis of ischemic colitis. This diagnosis was also supported by the imaging findings. The segmental nature of disease in this patient is much more common in patients with ischemic colitis than in those with infectious colitis. A target sign enhancement pattern can be seen in patients with ischemic colitis, as well as in patients with mild to moderate ascites (4). This finding may be related to superinfection of damaged colonic mucosa and is not necessarily related to transmural involvement (5). Thickened bowel walls may display low attenuation because of edema or high attenuation because of mucosal hemorrhage (6). Pneumatosis coli and portomesenteric venous gas, which were absent in this patient, are infrequent but ominous findings in the setting of ischemic colitis, although they are nonspecific as isolated findings. In a patient with ischemic bowel disease, they usually signify transmural infarction (7).
Imaging of patients presenting with signs and symptoms of ischemic colitis frequently begins with radiography of the abdomen to rule out bowel obstruction or perforation; however, CT is the mainstay in the radiologic evaluation of colitis. CT findings of ischemic colitis, however, can be difficult to distinguish from those of infectious colitis. The most reliable CT indicator of ischemic colitis is isolated disease in the left side of the colon: In a retrospective study involving 117 patients with documented colitis, 10 of 13 patients with proved ischemic colitis had disease limited to the left side of the colon, while none of the 11 patients with infectious colitis had exclusively left-sided disease (8). In a patient with right-sided colitis, the distinction is more difficult and is more dependent on the patient's history and clinical findings. Regardless of the location of disease within the colon, however, segmental involvement favors a diagnosis of ischemic colitis. In a study involving 54 patients with proved ischemic colitis, 89% of patients had segmental disease; this feature is rarely seen in patients with infectious colitis (4). The specific CT appearance of colonic ischemia isolated to the cecum is rare; however, it was described in a report of two patients (9): Pneumatosis was present in one patient. In the other, there was moderate circumferential thickening of the cecal wall, with a target sign enhancement pattern and mild pericecal stranding.
Although published estimates of the incidence of colonic ischemia vary (10), this disease is often cited as the most common intestinal vascular disorder, and it is one of the most frequent causes of colitis among elderly patients (11,12). Colonic ischemia is categorized as occlusive or nonocclusive. Causes of occlusive ischemic colitis include thrombosis, embolus, injury to the mesenteric vessels during aortic reconstructive surgery, trauma, and small-vessel disease due to diabetes, amyloidosis, radiation injury, or vasculitis. Nonocclusive disease can be caused by low flow states, such as shock or low-output cardiac failure; drugs, such as digitalis, diuretics, catecholamines, nonsteroidal antiinflammatory agents, or cocaine; colonic obstruction; or fecal impaction (13). In rare instances, occlusive ischemia is caused by venous obstruction secondary to hypercoagulable states, pancreatitis, portal hypertension, diverticulitis, or trauma (14). There is a wide range of presenting signs and symptoms. Abdominal pain, diarrhea, and abdominal distention each occur in about two-thirds of patients, whereas nausea, vomiting, or both occur in approximately one-third of patients. Rectal bleeding is also a common finding and is usually self-limited (13). Physical examination findings are frequently unremarkable unless transmural necrosis develops and causes peritoneal inflammation. Infarction and perforation are uncommon and occur in less than 5% of patients; however, when full-thickness disease is present, patients often present with symptoms of shock (15).
In light of the patient's history of aortic valve repair and recent cardiac catheterization, an embolic origin of ischemic colitis was considered. Cholesterol embolism of the cecum is a known complication of retrograde arteriography and is thought to result either from difficult manipulation of a catheter through an atherosclerotic aorta or from forced distention of the aorta by means of contrast material injection (16–18).
A nonocclusive origin, however, was just as likely in this patient. Although the right colon is not commonly considered a watershed area, in some patients it may be more vulnerable to nonocclusive ischemia than the traditional watershed segments, such as the splenic flexure (located at the junction between the superior mesenteric artery and the inferior mesenteric artery) and the rectosigmoid colon (where there is an anastomotic plexus between the inferior mesenteric artery and the hypogastric arteries) (19).
The cecum receives its blood supply from the anterior and posterior cecal arteries, which frequently arise from a vascular arcade between the ileal and colic branches of the ileocolic artery. Alternatively, the cecal arteries may arise directly from either the ileal artery or the colic artery. When this occurs, the cecum does not benefit from the collateral supply afforded by the vascular arcade; thus, it is at risk for ischemia during low flow states (20). In addition, it is thought that the inferior mesenteric artery is not controlled by the autonomic nervous system and that the left colon may thus "steal" perfusion from the right colon when there is mesenteric vasoconstriction involving the circulation of the celiac and superior mesenteric arteries, as may result from a low flow state (21). This patient had, in fact, recently begun taking a diuretic for heart failure related to worsening aortic stenosis; thus, she had multiple risk factors for nonocclusive ischemia.
It is difficult to assess the prognosis of a patient with ischemic colitis on the basis of CT findings alone. In the absence of portomesenteric venous air or intraperitoneal free air, it is impossible to predict the likelihood of complications, such as infarction and perforation (4). Thus, close clinical observation and prophylactic antibiotic therapy have been recommended; surgery is reserved for patients with signs of peritonitis, massive hemorrhage, sepsis, ischemic stricture, or chronic disease (22). It is also important that colonoscopy be performed as early as possible to enable the diagnosis of ischemic colitis to be confirmed, as submucosal lesions are best seen within 2 or 3 days after the onset of symptoms and they tend to resolve rapidly thereafter (13). This patient underwent colonoscopy, which revealed friable mucosa in the cecum. Biopsy findings were compatible with a diagnosis of ischemic colitis, and no cholesterol emboli were detected. In this patient, as in most patients with ischemic colitis (12), the specific cause could not be determined with certainty. Antibiotic treatment was initiated as a prophylaxis against superinfection, and the patient was followed up clinically. Symptoms resolved within 1 week.
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FOOTNOTES
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Authors stated no financial relationship to disclose.
| Part one of this case appeared 4 months previously and may contain larger images.
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References
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- Cellier C, Delabesse E, Helmer C, et al. Refractory sprue, celiac disease, and enteropathy-associated T-cell lymphoma. Lancet 2000;356:203–208.[CrossRef][Medline]
- Horton KM, Corl FM, Fishman EK. CT evaluation of the colon: inflammatory disease. RadioGraphics 2000;20:399–418.[Abstract/Free Full Text]
- Stockinger ZT. Colonic ameboma: its appearance on CT—report of a case. Dis Colon Rectum 2004;47:527–529.[CrossRef][Medline]
- Balthazar EJ, Yen BC, Gordon RB. Ischemic colitis: CT evaluation of 54 cases. Radiology 1999;211:381–388.[Abstract/Free Full Text]
- Wiesner W, Khurana B, Hoon J, Ros PR. CT of acute bowel ischemia. Radiology 2003;226:635–650.[Abstract/Free Full Text]
- Horton KM, Fishman EK. Computed tomography evaluation of intestinal ischemia. Semin Roentgenol 2001;36:118–125.[CrossRef][Medline]
- Bartnicke BJ, Balfe DM. CT appearance of intestinal ischemia and intramural hemorrhage. Radiol Clin North Am 1994;32:845–860.[Medline]
- Philpotts LE, Heiken JP, Westcott MA, Gore RM. Colitis: use of CT findings in differential diagnosis. Radiology 1994;190:445–449.[Abstract/Free Full Text]
- Simon AM, Birnbaum BA, Jacobs JE. Isolated infarction of the cecum: CT findings in two patients. Radiology 2000;214:513–516.[Abstract/Free Full Text]
- Higgins PD, Davis KJ, Laine L. Systematic review: the epidemiology of ischemic colitis. Aliment Pharmacol Ther 2004;19:729–738.[CrossRef][Medline]
- Boley SJ. Colonic ischemia: 25 years later. Am J Gastroenterol 1990;85:931–934.[Medline]
- Reinus JF, Brandt LJ, Boley SJ. Ischemic disease of the bowel. Gastroenterol Clin North Am 1990;19:319–343.[Medline]
- MacDonald PH. Ischaemic colitis. Best Pract Res Clin Gastroenterol 2002;16:51–61.[CrossRef][Medline]
- Choudhary AM, Grayer D, Nelson A, et al. Mesenteric venous thrombosis: a diagnosis not to be missed. J Clin Gastroenterol 2000;31:179–182.[CrossRef][Medline]
- Longo WE, Ballantyne GH, Gusberg RJ. Ischemic colitis: patterns and prognosis. Dis Colon Rectum 1992;35:726–730.[CrossRef][Medline]
- Chan T, Levine MS, Park Y. Cholesterol embolization as a cause of cecal infarct mimicking carcinoma. AJR Am J Roentgenol 1988;150:1315–1316.[Free Full Text]
- Gaines PA, Cumberland DC, Kennedy A, Welsh CL, Moorhead P, Rutley MS. Cholesterol embolization: a lethal complication of vascular catheterization. Lancet 1988;1:168–170.[Medline]
- Moolenaar W, Lamers CB. Cholesterol crystal embolization to the alimentary tract. Gut 1996;38:196–200.[Abstract/Free Full Text]
- Landreneau RJ, Fry WJ. The right colon as a target organ of nonocclusive mesenteric ischemia: case report and review of the literature. Arch Surg 1990;125:591–594.[Abstract]
- Rist CB, Watts JC, Lucas RJ. Isolated ischemic necrosis of the cecum in patients with chronic heart disease. Dis Colon Rectum 1984;27:548–551.[Medline]
- Connolly JE. The right colon as a target organ of nonocclusive mesenteric ischemia: case report and review of the literature—invited commentary. Arch Surg 1990;125:594.
- Sreenarasimhaiah J. Diagnosis and management of intestinal ischemic disorders. BMJ 2003;326:13723M-3M-213726.
Congratulations to the 49 individuals and five resident groups that submitted the most likely diagnosis (ischemic colitis limited to the cecum) for Diagnosis Please, Case 120. The names and locations of the individuals and resident groups, as submitted, are as follows:
Individual responses
- Hisashi Abe, MD, Suita City, Osaka, Japan
- Erhan Akpinar, Ankara, Turkey
- Mosleh M. Al Raddadi, MD, Madina, Saudi Arabia
- Jason B. Ashley, MD, London, Ontario, Canada
- Samir Ayat, MD, Bebeloved, Algeria
- Eric L. Bressler, MD, Minnetonka, Minn
- Douglas C. Brown, MD, Virginia Beach, Va
- Marcelo Cabrini, Lomas de Zamora, Argentina
- Marcos N. Chagas, MD, Brasilia, Brazil
- Natesan Chidambaranathan, MD, Chennai, India
- Honorio Chiminazzo, MD, Campinas, Brazil
- Peter De Baets, Damme, Belgium
- Thaworn Dendumrongsup, MD, Songkla, Thailand
- Walter T. Depaulaneto III, MD, Rio de Janeiro, Brazil
- Michael D. Edwards, MD, Knoxville, Tenn
- Seyed A. Emamian, MD, PhD, Rockville, Md
- Virginia Fattal Jaef, MD, Rosario, Argentina
- Vidisha V. Ghole, MD, Irving, Tex
- Francisco Jose Gonzalez, Santander, Spain
- Dipali D. Gurav, MBBS, Nellore, India
- Irith Hadas-Halpern, MD, Jerusalem, Israel
- Waleed M. Ibrahim, MD, Columbus, Ohio
- Rathachai Kaewlai, MD, Boston, Mass
- Kiriakos Kalampoukas, MD, Halandri, Greece
- Masako Kataoka, MD, Cambridge, United Kingdom
- Ulku Kerimoglu, MD, Ankara, Turkey
- Steven A. Klein, MD, Shrewsbury, Mass
- Stefanos Lachanis, Athens, Greece
- Mario A. Laguna, MD, Milwaukee, Wis
- Nikolaos Michailidis, Thessaloniki, Greece
- Jose Mondello, MD, Buenos Aires, Argentina
- Tammam N. Nehme, MD, East Wenatchee, Wash
- Mizuki Nishino, MD, Boston, Mass
- Anietie E. Okon, MD, North Liberty, Iowa
- Yeliz Pekcevik, Izmir, Turkey
- Ivan Pilate, Brussels, Belgium
- Roberto Q. Santos, MD, Rio de Janeiro, Brazil
- Steven M. Schultz, MD, Fort Worth, Tex
- Matthew P. Shapiro, MD, Charlottesville, Va
- David F. Sobel, MD, La Jolla, Calif
- Luis A. Sosa, Jr, MD, Mexico City, Mexico
- Subramanian Subramanian, MD, New Delhi, India
- Douglas L. Teich, MD, Brookline, Mass
- Baris I. Turkbey, MD, Ankara, Turkey
- Eleni Vafeiadou, Thessaloniki, Greece
- David C. Wilkes, MD, Dallas, Tex
- Stanko Yovichevich, MD, Sydney, Australia
- Joe Yut, Olathe, Kan
- Navid A. Zenooz, MD, Cleveland Heights, Ohio
Resident group responses
- Hospital Italiano Cordoba Radiology Residents, Cordoba, Argentina
- Prince of Songkla University Radiology Residents, Hat Yai, Songkla, Thailand
- Santa Casa da Misericórdia do Rio de Janeiro Radiology Residents, Rio de Janeiro, Brazil
- Trakya University School of Medicine Radiology Residents, Edirne, Turkey
TOP
HISTORY
IMAGING FINDINGS
