Figure 1
Ischaemic colitis: CT after pneumocolon and administration of contrast medium i.v.
Air insufflation failed to dilate a portion of the left colon, which appears stenotic with thickened walls.
Clinical History
The patient presented with a 24-hour history of cramping pain in the left abdominal region associated with dark red clots per rectum.
Imaging Findings
The patient presented with a 24-hour history of cramping pain in the left abdominal region associated with dark red clots per rectum. The patient was also affected by many chronic diseases including diabetes and hypertension. On physical examination, there was guarding and tenderness in the left lower quadrant. Fibreoptic colonoscopy was performed, but results were incomplete because the descending colon appeared narrowed and filled with red clots. An abdominal CT examination was performed immediately.
To obtain an accurate CT study of the colonic walls air was insufflated into the colon (pneumocolon), and CT scans were acquired before and after intravenous administration of contrast. CT scans demonstrated an extensive area of circumferential thickening of the wall of the splenic flexure and descending colon. The lumen of the descending colon was irregularly narrowed by a process analogous to the “thumbprinting” of submucosal oedema and the target sign was also present suggesting ischaemic colitis.
The patient underwent surgery the next day. At surgery the descending colon was inflamed, ulcerated, and oedematous with multiple haemorrhages in the bowel wall. The histological findings were those of ischaemic colitis.
Discussion
Ischemic colitis is a common cause of abdominal pain in the elderly and represents the most common form of the gastrointestinal ischaemia. Colonic ischaemia may be caused by arterial occlusive disease, venous occlusive disease and non-occlusive ischaemia resulting from low-flow states. Ischaemic colitis comprises a wide spectrum of pathological and clinical findings, ranging from a mild self-limiting form to bowel infarction and perforation. The histopatological manifestations of ischaemic colitis are mucosal necrosis and ulcerations, submucosal oedema and haemorrhage, or transmural infarction. In accordance with the degree of ischaemic damage this entity is classified into gangrenous and non-gangrenous forms (including the transient and the stricturing form).
Ischaemic colitis can affect the entire colon, but more often there is a segmental distribution. The splenic flexure and sigmoid colon are particularly susceptible to ischemia due to hypovolaemia. These regions represent areas of relatively poor perfusion at the border of major vascular territories.
The clinical presentation of bowel ischaemia may be acute, with abrupt onset of severe symptoms, subacute, or chronic, with low grade intermittent symptoms. Abdominal pain, which may be crampy initially, develops in patients with acute bowel ischaemia. Diarrhoea may develop, and stools may be positive on fecal occult blood testing or may be overtly bloody. An elevated white blood cell count, fever, and signs of peritonitis may develop as the ischaemia persists and infarction develops. Therapy and outcome are dependent on the severity of the disease.
Radiological assessment of colonic ischaemia is traditionally based on plain radiography of the abdomen, instant enema and barium studies (for demonstration of thumbprinting, ulcerations, stenosis and sacculations), and angiography. However, advances in CT technology allow the increased employment of CT studies for the evaluation of patients with suspected colonic ischaemia. In cases of colonic ischaemia, CT typically demonstrates circumferential, symmetric wall-thickening with fold enlargement. A double halo or target sign may also be evident. The colonic wall may demonstrated low attenuation due to oedema or high attenuation indicating intramural haemorrhage. Inflammatory changes in the pericolic fat may also be present. In cases of occlusive ischaemia, CT can demonstrate thrombus within the splancnic vessels or invasion of vessels by tumours such as pancreatic cancer. Pneumatosis can also be demonstrated. Thus CT findings can improve the early diagnosis of colonic ischaemia in an appropriate clinical setting.
Differential Diagnosis List
Ischaemic colitis
Final Diagnosis
Ischaemic colitis
References
[1] Balthazar EJ, Yen BC, Gordon RB. Ischemic colitis: CT evaluation of 54 cases. Radiology 1999;211(2):381-8. (PMID: 10228517)
[2] Toursarkissian B, Thompson RW. Ischemic colitis. Surg Clin North Am. 1997;77(2):461-70. (PMID: 9146725)
[3] Horton KM, Fishman EK. Computed tomography evaluation of intestinal ischemia.Semin Roentgenol. 2001;36(2):118-25. (PMID: 11329654)
Case information
| URL: | https://eurorad.org/case/1290 |
| DOI: | 10.1594/EURORAD/CASE.1290 |
| ISSN: | 1563-4086 |
Figure 3
CT after pneumocolon and administration of contrast medium i.v.
Pneumatosis in the colonic wall of the splenic flexure can be seen.
Figure 4
CT after pneumocolon and administration of contrast medium i.v.
A thickened wall can be seen at the splenic flexure.
Ischaemic colitis: CT after pneumocolon and administration of contrast medium i.v.
Air insufflation failed to dilate a portion of the left colon, which appears stenotic with thickened walls.
CT after pneumocolon and administration of contrast medium i.v.
Pneumatosis in the colonic wall of the splenic flexure can be seen.
CT after pneumocolon and administration of contrast medium i.v.
A thickened wall can be seen at the splenic flexure.