1

1. RADIOLOGY
INFLAMATORY BOWL DISEASE

2. INTRODUCTION
• Group of chronic disorder that cause inflammation and ulceration in small and
large bowel. Mostly crohn’s disease and ulcerative colitis.

3. CROHN’S DISEASE
• Idiopathic, chronic, transmural inflammatory process of bowel - affect whole Gl
system starting from mouth to anus.
• Most commonly involved-terminal ileum, ileocaecal valve and caecum with
regional enteritis.
• SKIP LESIONS ARE PATHOGNOMIC
• Diagnosed typically between 15-25 years of age group.
• Smokers-more affected.
• Disease re-activation by triggers like stress , dietary factors and smoking.
• Risk of colonic adenocarcinoma.

4. On x ray plain radiograph of abdomen is usually helpful in cases of
obstruction secondary to chron’s disease.
Supine and erect projections.
Dilated small loops with air-
fluid levels within the central
portion of the abdomen are
suggestive of bowel
obstruction. Moderate fecal
loading within the rectum is
noted.The pleural bases are
clear.

5. BARIUM SMALL BOWEL FOLLOW THROUGH
• MUCOSAL ULCERS :- APHTHOUS ULCERS initially
• deeper transmural ulcers typically either longitudinal or circumferential in
orientation
• when severe leads to COBBLESTONE APPEARANCE
• may lead to sinus tracts and fistulae
• thickened folds due to oedema
• pseudodiverticula formation: due to contraction at the site of ulcer with ballooning
of the opposite site
• STRING SIGN: tubular narrowing due to spasm or stricture depending on
chronicity partial obstruction

6. APTHOUS ULCERS :- FIRST SIGN OF CHORN’S DISEASE

7. Cobblestone appearance :- due to deep fissuring ulcers around infammed mucosa

8. Fissuring ulceration in Crohn’s disease:- called raspberry thorn
ulcer

9. String sign :- spasm/fibrosis of bowel wall
Ileoileal fistula :- long standing chron’s disease

10. Ultrasound
• Typically examination is limited to the small bowel and wall thickness
assessed:
• Bowel wall thickness should be <3 mm, normally
• thickness < 3 mm helps exclude the disease in a low risk patient.
• thickness > 4 mm helps establish the diagnosis in a high risk patient.
• Ultrasound in the assessment of extraintestinal manifestations.

11. US image :- stricture in patient with active Crohn’s disease

12. CT FINDING
• FAT HALO SIGN:- thickened bowel wall demonstrating 3 layer
• COMB SIGN:- engorgement of the mesenteric vessels with vascular dilatation,
tortuosity with spacing of the vasa recta, and prominence of surrounding
mesenteric fat resembling a comb
• Bowel wall enhancement
• Bowel wall thickening (1-2 cm):—terminal ileum
• strictures and fistulae
• mesenteric/intra-abdominal abscess or phlegmon formation

13. FAT HALO SIGN
Fat halo sign in chron's disease
Transverse CT scan shows the central fatty
submucosal layer of low attenuation (*)
surrounded by higher-attenuation inner (long
arrow) and outer(short arrow) layers grossly
corresponding to the mucosa and muscularis
propria and serosa of the descending colon,
respectively.

14. COMB SIGN

15. CECT :- CORONAL SECTION VENOUS PHASE - ENTROCECAL FISTULAA
WITH SECENDARY TRACTION OF CECUM AND RIGHT PSOAS MUSCLES ABSECESS

16. CT AND MR ENTEROGRPHY
• Useful for both mural and extramural spread of disease.
• Inflammed bowel loops show thickening and contrast enhancement.
• Extramural spread: fibrofatty proliferation-thickening of extramural fat:vascular
engorgement(comb sign)
• Stenosis and strictures
• MRI enteroclysis - placement of a nasojejunal catheter through which 1.5-2 L
of contrast solution (e.g. water with polyethylene glycol and electrolytes) are
injected.
• When disease is transmural, with cobblestone appearance, the abnormalities
are evident as high T2 signal linear regions.

17. CT ENTEROCLYSIS
• Introduction of the 12 to 14-F enteroclysis tube (under fluoroscopy or through
duodenoscope).
• Contrast is administered either on the fluoroscopy table or after transferring
the the patient to the CT unit for commencement of the CT scan (usually 1.5-
2L of oral contrast).
• In the CT unit, the position of the enteroclysis tube is checked in the topogram.
• In case negative oral contrast will be used, intravenous contrast injection will
be given (approximately 100-150ml).

18. Asymmetric mural hyperenhancement
Coronal contrast-enhanced fat-
suppressed T1-weighted MR
enterography image with biphasic oral
contrast material and coronal contrast-
enhanced CT enterography image
with neutral oral contrast material
MRI shows
good
opacification of
small and large
bowl with
thickening of
inflamed recall
wall

19. ULCERTIVE COLITIS
• Causes superficial ulceration of colon and rectum.
• It starts from rectum and retrogradely involves whole colon continuously.
• More common in DR2 related genes.
• More female predilection, age group 30-40 yrs.
• Clinical symtoms- diarrhoea, tenesmus, bleeding per rectum, passage of mucus, crampy abdominal
pain.
• MILD DISEASE: fine granularity
• MODERATE: marked erythema,coarse granularity, contact bleeding and no ulceration.
• SEVERE:spontaneous bleeding,edematous and ulcerated
• Long standing cases epithelial regeneration- pseudopolyps, pre cancerous condition
• Eventually shortening and narrowing of colon
• FULMINANT DISEASE:toxic colitis/megacolon

20. Acute UC-descending colon has
irregular outline. No fecal
residue in colon
:-Mucosal inflammation-granular appearance to the surface of the bowel.
:-Mucosal ulcers are undermined -button-shaped ulcers
:-Islands of mucosa remain giving it a pseudo-polyp appearance
:-In chronic cases the bowel becomes featureless with loss of normal
haustral markings, luminal narrowing and bowel shortening- lead pipe sign
BARIUM ENEMA

21. FINE MUCOSAL
GRANULARITY:- FIRST
SIGN NARROWING OF
LUMEN
COLLAR BUTTON
ULCERS

22. CT FINDING
• Inflammatory pseudopolyps
• Inflamed and thickened bowel - target appearance, due concentric rings of
varying attenuation-mural stratification
• In chronic cases, submucosal fat deposition is seen particularly in the rectum
fat halo sign
• Extramural deposition of fat, leads to thickening of the perirectal fat,widening
of the presacral space
• Marked muscularis mucosa hypertrophy-lead pipe sign.

23. PSEUDOPOLYP IN
ULCERATIVE COLITIS LEAD PIPE COLON

24. MRI
• Wall Thickening- median wall thickeness of colon ranges from 4.7 to 9.8 mm,
more severe the disease more thicken the wall
• Increased Enhancement-enhancement of the mucosa with no or less
enhancement of the submucosa
• Loss of haustral markings

25. MRI REVELS THICKENNING OF COLON WITH LOSS OF HASTRAL MARKINGS