Chronic, relapsing granulomatous inflammatory disease with predominant involvement of gastrointestinal tract

Bowel wall thickening

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  Adults: > 3 mm

  
  
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  Children: Small bowel thickness > 2.5 mm and large bowel wall thickness > 2 mm

Loss of normal bowel wall stratification

Hyperemia of bowel wall correlates with disease activity

Increased superior mesenteric artery (SMA) flow volume and decreased SMA resistive index correlate with disease activity

Thickening/increased echogenicity of mesentery

Anywhere from mouth to anus: Terminal ileum (95%), colon (22-55%), rectum (14-50%)

Look for skip lesions

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  Normal bowel between areas of involved bowel

Complications: Phlegmon and abscess, fistulas (enteroenteric, enteromesenteric, enterocutaneous, enterovesical, enterovaginal), bowel dilatation

Undiagnosed or suspected patients stratified into high or low risk based on symptoms, laboratory values, physical exam, and family history

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  Low risk: Ultrasound or MRE recommended

  
  
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  High risk: MRE or CTE

Newly diagnosed patients

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  MRE or CTE

Infectious colitis

Ulcerative colitis

Lymphoma

Appendicitis

Disease severity scored clinically using Crohn Disease Activity Index and Pediatric Crohn Disease Activity Index

18-25 years, 20-30% < 20 years; M = F

Smaller peak: 50-80 years

More common in Caucasian, Jewish populations

Recurrent abdominal pain and diarrhea, weight loss, fatigue, poor growth/weight gain, anemia, anorexia, nutritional deficiencies, and bowel obstruction

Penetrating &/or stricturing disease alters clinical management

Evaluate for associated abnormalities in other organs (primary sclerosing cholangitis, arthritis, gallstones, and urolithiasis)

Best evaluated with combination of linear and curved transducers, including endoluminal transducers