Comparison of Imaging Modalities for
Diagnosing and Monitoring Crohn’s Disease
5-000-485
Diagnosing Crohn’s Disease (CD)
• Diagnosis is based on a comprehensive evaluation of
clinical symptoms, small bowel radiology, endoscopy,
and laboratory testing of blood, stool, and mucosal
tissue (biopsy)1,2
• There is a poor correlation between symptom scores
and degree of inflammation2
• Average lag time between onset of symptoms and
reaching a diagnosis is 35 months3
1. CCFA: Crohn’s & Colitis Foundation of America Web site. http://www.ccfa.org/info/about/.
2. Leighton JA et al. Gastrointest Endosc. 2006;63(4):558-565.
3. Mekhjian HS et al. Gastroenterology. 1979;77(4 Pt 2):898-906.
Current Practice
• Imaging Modalities for Crohn’s Disease1
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Small Bowel Follow Through (SBFT)/Small Bowel Enteroclysis
Colonoscopy + Ileoscopy (C+I)
Computed Tomography (CT) Enterography/CT Enteroclysis
Magnetic Resonance (MR) Enterography/MR Enteroclysis
Double Balloon Enteroscopy (DBE)
Capsule Endoscopy (CE)
• ASGE practice guidelines recommend that C+I be performed
during the initial evaluation of patients with a clinical
presentation suggestive of inflammatory bowel disease (IBD)
and for differentiating ulcerative colitis (UC) from CD2
• CT plays a relevant role in assessing extra-luminal
complications (abscesses) and extra-enteric abnormalities3
1. Solem CA et al. Gastrointest Endosc. 2008;68(2):255-266.
2. Leighton JA et al. Gastrointest Endosc. 2006;63(4):558-565.
3. Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
Small Bowel Follow Through/Enteroclysis
• A radiologic examination of the small intestine from the distal
duodenum/duodenojejunal junction to the ileocecal valve
•
Advantages
• Low cost
• Sensitivity, 85%–95%; specificity, 89%–94% for CD when performed by
experienced examiners1
• Can reveal ulcerations, narrowing, and fistulae of the bowel1
• Poor sensitivity and specificity for suspected and mild CD
•
Disadvantages
• Discomfort of NJC for barium placement
• Radiation exposure
• Inability to obtain biopsy or mark abnormalities for surgery
• CE allows direct visualization of subtle mucosal inflammatory
changes or erosions present in early CD that are not commonly
seen in barium studies2
1. Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
2. Hara AK et al. RadioGraphics. 2005;25:697-718.
Colonoscopy With Ileoscopy
• Direct visualization of the rectum, large intestine, and terminal
ileum
•
•
Advantages
• More accurate than barium x-rays in detecting small ulcers or areas of
inflammation
• Ability to obtain a biopsy sample or mark abnormalities for surgery
Disadvantages
• Invasive
• Requires a colon preparation
• Inability to visualize the small bowel (ileum only)
• Contraindicated in severe colitis or toxic megacolon
• ASGE practice guidelines recommend that C+I be performed
during the initial evaluation of patients with a clinical
presentation suggestive of IBD and for differentiating UC from CD
• Endoscopy together with other diagnostic modalities can differentiate CD
from UC in ≥85% of patients
Leighton JA et al. Gastrointest Endosc. 2006;63(4):558-565.
Mucosal Biopsy
• Mucosal biopsy is a critical component of endoscopic examination for
patients with suspected IBD to differentiate IBD from other colitis,
such as bacterial infection, ischemia, and NSAID use, as well as to
differentiate CD from UC
• Mucosal biopsy helps to establish the extent of colon that is
inflamed, which aids in determining prognosis, directing appropriate
therapy, and stratifying risk for dysplasia
• Determination of extent of colitis should be based on histologic
examination rather than on endoscopy
• However, the frequency of detection of granulomata varies from 15%
to 36% of endoscopic biopsy specimens, and granulomas are not
characteristic for CD
• Specimens should be taken from the edges of multiple ulcers and
aphthous erosions and from normal-appearing mucosa
Leighton JA et al. Gastrointest Endosc. 2006;63(4):558-565.
Capsule Endoscopy Helps Guide Management When
Endoscopy and Histology Findings Are Discordant
• 129 CE cases for suspected CD were reviewed
• A discordant finding was defined as a normal endoscopy with
abnormal biopsy, or the converse
• Findings were consistent with CD for 63 patients
• Of the 63 patients with CD, 30 patients had complete colonic and
ileal data with biopsy results
• Discordance between histology and endoscopy occurred for 17% of
patients with both endoscopy and biopsy results
• The locations of the CE findings were 23% in the jejunum, 23% in
the ileum, and 54% in both areas of the small bowel
• CE was helpful in guiding management when the endoscopy and
histology results did not agree
Shepela C et al. Gastrointest Endosc. 2009;69(5):AB287.
Computed Tomography (CT)
Enterography/Enteroclysis
• Computerized radiologic procedure used for the detection of intra-abdominal
abscesses, strictures, pre-stenotic dilatations, fistulae
• CT plays a relevant role in assessing extra-luminal complications (abscesses)
and extra-enteric abnormalities
• Findings observed in CD include small bowel wall stratification and/or
thickening, edema of the mesenteric fat, engorged ileal vasa recta,
submucosal fibro-fatty infiltration, and mesenteric adenopathy
• Advantages
• Comprehensive structural assessment of the abdomen, pelvis, and small bowel
• Sensitivity, 71%–83%; specificity, 90%–98% for CD1
• Disadvantages
• Discomfort of nasojejunal catheter (NJC) for barium placement
• Exposure to radiation: 1.5%-2% of all cancers in the U.S. may be attributed to
radiation from CT studies
• Inability to obtain biopsy or mark abnormalities for surgery
• Ability to assess disease activity unclear
Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
Brenner DJ et al. N Engl J Med. 2007;357(22):2277-2284.
Capsule Endoscopy and Computed Tomography
Are Complementary
• CT has specific roles in determining the extent of
established small bowel CD
• CE gives unparalleled depiction of the mucosal surface
of the small bowel
• CT may help establish the presence of strictures and
determine if CE can be used safely to show extent of
disease
Maglinte D et al. Radiology. 2007;245(3):661-671.
Magnetic Resonance (MR)
Enterography/Enteroclysis
• Non-ionizing radiation diagnostic technique; able to obtain multiplanar diagnostic information about intra- and extra-mural
involvement of the small bowel1
• Good correlation between the degree of wall enhancement after
intravenous (IV) contrast injection and disease activity (calculated
using Crohn’s Disease Activity Index) has been obtained, with overall
high specificity for MR findings
• Advantages
• Comprehensive structural assessment of the abdomen, pelvis, and small
bowel
• >80% sensitivity and specificity for CD1
• Disadvantages
• Discomfort of nasojejunal catheter for barium placement
• Inability to obtain biopsy or mark abnormalities for surgery
• Expensive
1. Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
Double Balloon Endoscopy
• Also known as “push and pull enteroscopy,” a balloon at the end of
a special enteroscope camera and an overtube is inserted through
the mouth and passed into the small bowel. Using the assistance of
friction at the interface of the enteroscope and intestinal wall, the
small bowel is accordioned back to the overtube. The overtube
balloon is then deployed, and the enteroscope balloon is deflated.
The process is continued until the entire small bowel is visualized
• Advantages
• Allows complete endoscopic evaluation of the small bowel1
• Ability to obtain a biopsy sample1
• Able to carry out therapeutic interventions along the entire small
bowel1
• Disadvantages
• Inconvenient and invasive
• Requires specialized equipment, sedation, fluoroscopy, and prolonged
examination time1
1. Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
Capsule Endoscopy
• Swallowable wireless video capsule that transmits images during
passive movement through the GI tract
• Advantages
• Non-invasive, painless, disposable
• Permits direct visualization and high-resolution images of the entire
small bowel1
• May help identify superficial lesions not detected by traditional
endoscopy and radiology2
• Sensitivity 93%; specificity 84% for CD1
• Disadvantages
• Inability to obtain biopsy or mark abnormalities for surgery2
• Contraindicated when strictures are suspected (risk of capsule
retention) and in patients with swallowing difficulty or who use
pacemakers or other implanted electromedical devices1,3
• Historic concern over high sensitivity with low specificity
1. Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
2. Leighton JA. Gastrointest Endosc. 2006;63(4):558-565.
3. Hara AK et al. RadioGraphics. 2005;25:697-718.
The Value of Capsule Endoscopy in Suspected
Crohn’s Disease
• In patients in whom a case of CD is suspected (newly diagnosed
disease), CE has a low retention rate of 1%–2% and a higher diagnostic
yield than small bowel barium studies, conventional CT, CT
enteroclysis, or CT enterography1
• After negative colonoscopy and ileoscopy findings, CE is considered to
be the first-line examination in the investigation of suspected nonstricturing CD1
1. Maglinte D et al. Radiology. 2007;245(3):661-671.
Imaging Modalities Key Points
• Diagnosis of CD is based on an evaluation of symptoms,
small bowel radiology, endoscopy, and laboratory testing of
blood, stool, and biopsy
• Radiology examinations (SBFT) have poor sensitivity in the
detection of early inflammatory lesions1
• CT and CE are complementary in identifying findings associated with
CD
• A rough approximation of radiation exposure from 1 abdomen pelvis
CT in an adult is equal to 100 to 250 chest x-rays2
• Endoscopy is limited to the most distal and proximal
portion of the small bowel1
• Granulomas (biopsy) are not characteristic for CD (ASGE)
1. Triester SL et al. Am J Gastroenterol 2006;101(5):954-964.
2. GIST Support International. www.gistsupport.org. Accessed July 9, 2009.
Imaging Modalities Key Points:
Capsule Endoscopy
• Considered standard practice in investigating diseases of
the small intestine1,2
• Useful for differentiating Crohn’s disease (CD) from
ulcerative colitis (UC) or indeterminate colitis (IC), for
detecting recurrences, for establishing extent of disease,
and for assessing response to therapy3
• Allows the detection of small bowel changes that are not
within reach of push enteroscopy3
• Allows direct visualization of the small bowel, and can
detect subtle mucosal inflammatory changes or erosions
present in early CD that are not commonly seen in barium
studies
1. Saibeni S et al. World J Gastroenterol. 2007;13(24):3279-3287.
2. Westerhof J et al. Minerva Gastroenterol Dietol. 2008;54(2):189-207.
3. Leighton JA et al. Gastrointest Endosc. 2006;63(4):558-565.