Case of the week Details

FINDINGS

DIAGNOSIS

• Crohn’s disease with ileal perforation and peritonitis.

DISCUSSION:

• Crohn disease is an idiopathic inflammatory bowel disease characterized by discontinuous gastrointestinal tract inflammation.
• The terminal ileum and proximal colon are most often affected.
• Patients typically present with chronic diarrhea and recurrent abdominal pain, although occasionally the presentation is with a complication or an extraintestinal manifestation.
• CT is the first imaging assessment for patients in the setting of an acute abdomen or for reassessment of complications in patients with known Crohn disease.

Common CT Imaging features include:

• Mural hyperenhancement
• Fat halo sign: submucosal fat deposition
• Bowel wall thickening which is most frequently seen in the terminal ileum.
• Comb sign: engorgement of the vasa recta
• Perienteric fat stranding.
• Affected bowel loops separated by focal/regionally increased fat (fibrofatty proliferation; creeping fat)
• Strictures and fistulae with upstream dilatation.
• Mesenteric/intra-abdominal abscess or phlegmon formation

Complications include:

• Strictures.
• Adhesions and bowel obstructions.
• Fistulae.
• Perianal fistula.
• Perianal abscess.
• Bowel perforation with free peritoneal air is a rare complication of Crohn’s disease.
• It is seen to occur in 1–3% of Crohn’s disease patients as a first manifestation or, in the course of the disease.
• Early diagnosis of bowel perforation is important and determines the survival rate.
• Only 20% of patients with Crohn’s disease and intestinal perforation have pneumoperitoneum on X-ray of the abdomen and/or on erect chest X-ray. Thus CT plays a pivotal role in accurate diagnosis of both Crohn’s disease and also in determining the site of intestinal perforation.
• Laparotomy and bowel resection should be considered if the perforation place is identified. However, in the absence of a clear site of perforation and without enteric contamination, a conservative surgical approach should be considered.

REFERENCES

• Furukawa A, Saotome T, Yamasaki M et al. Cross-Sectional Imaging in Crohn Disease. Radiographics. 2004;24(3):689-702. doi:10.1148/rg.243035120 – Pubmed
• Gore R, Balthazar E, Ghahremani G, Miller F. CT Features of Ulcerative Colitis and Crohn’s Disease. AJR Am J Roentgenol. 1996;167(1):3-15. doi:10.2214/ajr.167.1.8659415 – Pubmed.
• R.F. Leal et al. Free peritoneal perforation in a patient with Crohn’s disease – Report of a case. International Journal of Surgery Case Reports 4 (2013) 322–324.

Dr. Vishwanath Joshi
Consultant Radiologist.
Manipal Hospital Radiology Group (MHRG)
Manipal Hospital, Bengaluru.

Dr Rashmi Jayakar Poojary
Radiology resident
Manipal  Hospital, Yeshwanthpur, Bengaluru.