Fluoroscopy Contrast Enema Colonoscopy is the preferred examination of the colon in patients suspected of having inflammatory bowel disease [9]. It is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the initial diagnostic examination [9]. Although contrast enemas can detect fistulas to other organs and sinus tracts, it is poor for abscess determination given its non-cross-sectional nature. HMPAO WBC Scan Leucoscintigraphy, or Tc-99m-HMPAO WBC scan, have demonstrated good sensitivities and specificities for intestinal inflammation in the 79% to 85% and 81% to 98% range, respectively [98]. Proponents contend that leucoscintigraphy is useful in the diagnosis and evaluation of activity and extent of disease [99] with performance results equivalent to cross-sectional imaging [28]. However, the disadvantages of this examination, such as the decreased ability to depict and therefore detect alternative diagnoses and the complicated time-consuming technical aspects (ie, labeling and handling of blood products), have limited its use in evaluation. FDG-PET/CT Skull Base to Mid-Thigh The addition of metabolic information from PET with the morphologic anatomic imaging of CT or MR shows promise. It may be helpful to better assess the level of active inflammation from fibrosis [100,101]. Studies also show improved assessment in the colon in a murine animal model [102], which points to potential future usefulness because the colon is less well evaluated with both CT enterography and MR enterography. At this point, there are few large-series published clinical studies, but small series show promising results [103,104]. Variant 3: Known Crohn disease, disease surveillance; monitoring therapy. In this clinical scenario, the purpose of the imaging evaluation is to determine the presence or absence of disease activity in a relatively well CD patient (ie, mildly symptomatic to asymptomatic) in order to help determine medical management.
Crohn Disease. Fluoroscopy Contrast Enema Colonoscopy is the preferred examination of the colon in patients suspected of having inflammatory bowel disease [9]. It is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the initial diagnostic examination [9]. Although contrast enemas can detect fistulas to other organs and sinus tracts, it is poor for abscess determination given its non-cross-sectional nature. HMPAO WBC Scan Leucoscintigraphy, or Tc-99m-HMPAO WBC scan, have demonstrated good sensitivities and specificities for intestinal inflammation in the 79% to 85% and 81% to 98% range, respectively [98]. Proponents contend that leucoscintigraphy is useful in the diagnosis and evaluation of activity and extent of disease [99] with performance results equivalent to cross-sectional imaging [28]. However, the disadvantages of this examination, such as the decreased ability to depict and therefore detect alternative diagnoses and the complicated time-consuming technical aspects (ie, labeling and handling of blood products), have limited its use in evaluation. FDG-PET/CT Skull Base to Mid-Thigh The addition of metabolic information from PET with the morphologic anatomic imaging of CT or MR shows promise. It may be helpful to better assess the level of active inflammation from fibrosis [100,101]. Studies also show improved assessment in the colon in a murine animal model [102], which points to potential future usefulness because the colon is less well evaluated with both CT enterography and MR enterography. At this point, there are few large-series published clinical studies, but small series show promising results [103,104]. Variant 3: Known Crohn disease, disease surveillance; monitoring therapy. In this clinical scenario, the purpose of the imaging evaluation is to determine the presence or absence of disease activity in a relatively well CD patient (ie, mildly symptomatic to asymptomatic) in order to help determine medical management.