Crohn’s disease is a chronic inflammatory disease of the digestive tract that can involve from mouth to anus. The exact cause of Crohn’s is unknown. CT imaging of Crohn’s disease can identify areas of involvement and complications.
What is Crohn’s Disease?
Crohn’s disease is an inflammatory disease of unknown cause involving the digestive tract. Crohn’s is diagnosed in teenage and young adulthood years most commonly.
It most commonly involves the intestines and large bowel. Crohn’s can involve multiple discontinuous areas of the digestive tract.
Symptoms of Crohn’s Disease
Crohn’s disease can present with chronic diarrhea, abdominal pain, weight loss, anemia, fever, loss of appetite to name some.
What does Crohn’s Disease look like on a CT scan?
Crohn’s disease on CT often involves thickening of the last part of the intestine called the terminal ileum. Other involved parts of the bowel will also be thickened in appearance.
The involved bowel enhances to a greater degree than normal bowel.
The blood vessels feeding the involved bowel will be bigger and engorged.
There may be fat stranding or inflammation around involved bowel loops.
Crohn’s causes strictures or narrowing of bowel loops. There can be a blockage of the bowel at the site of narrowing.
There can be a fistula formed. This is an abnormal communication between structures like bowel to bladder or intestine to vagina.
Collections of pus called abscesses can form. Inflammatory masses called phlegmon can form.
CT can also tell us if there is disease around the anus or in the liver.
Does Crohn’s Disease always show up on CT scan?
No. We can have involvement without identifying Crohn’s on CT.
Is Crohn’s disease limited to the digestive tract?
No. Crohn’s disease can involve multiple sites outside the digestive tract. There can be arthritis, involvement of the eyes, skin, liver, biliary system, kidneys and lungs.
What diagnostic test confirms Crohn’s Disease?
Colonoscopy is one of the best er tests. This involves placing a flexible tube with camera into your colon and looking for signs of disease. Biopsies are also taken to determine if there is Crohn’s involvement.
What can be mistaken for Crohn’s Disease?
Ulcerative colitis is another cause of inflammatory bowel disease which primarily involves the colon and rectum.
Infectious colitis is that caused by an organism and can have a similar appearance on CT.
Ischemic colitis is caused by reduced blood flow to the colon. The CT appearance can mimic Crohn’s.
Cancer can cause thickening of the bowel.
Involvement of the small intestine by Crohn’s can also be mimicked by infections, ischemic bowel, and secondary causes of inflammation.
What causes Crohn’s Disease ?
It is not certain. A combination of genetic predisposition and immune response to bacterial agents has been proposed.
Is Crohn’s Disease dangerous?
It can be because the complications can involve bowel obstruction, abscess formation, fistulas and cancer of the bowel. There are multiple important extra intestinal complications as well.
Crohn’s Disease treatment
Crohn’s disease management is complex and often handled by a digestive disease specialist (gastroenterologist). The disease is chronic with flare ups. There is no cure.
Treatment can include diet, medications like immunomodulators and steroids, and surgery. Surgery is reserved for complications like bowel blockages, fistulas and anal involvement.
Crohn’s Disease on CT scan : summary
Crohn’s disease is an inflammatory disease of the digestive tract, most commonly involving the intestine and large bowel. CT imaging can identify involved segments of the bowel, complications, and involvement outside the digestive tract. Crohn’s disease is a chronic disease with flares. Treatment is complex and often managed by a specialist.