Validation of a lower radiation computed tomography enterography imaging protocol to detect Crohn's disease in the small bowel.
BACKGROUND
The purpose was to validate a lower radiation dose computed tomography enterography (CTE) imaging protocol to detect the presence of Crohn's disease (CD) in the small bowel using two different reference standards and to identify a prediction model based on CTE signs for the presence of active CD.


METHODS
This retrospective study included patients with known or suspected CD who underwent CTE between January and October 2006 according to a lower radiation dose protocol. Two gastrointestinal radiologists blindly and independently classified each CTE as being active or inactive. Reference standards included ileocolonoscopy ± biopsy and a comprehensive clinical reference standard (retrospectively created by a gastroenterologist, also including history, physical, follow-up course, and subsequent endoscopy, imaging, or surgery). Logistic regression was used to identify CTE findings that predicted the presence of active CD based on the combined clinical reference standard.


RESULTS
In all, 137 patients underwent CTE and ileocolonoscopy. Using an endoscopic reference standard, the sensitivity of CTE to detect active CD for the two readers was 81% and 89%, respectively. Using the clinical reference standard, the sensitivity of CTE to detect active CD was 89% and 98%, respectively. For both readers the sensitivity of CTE increased by 8%-9% when using the comprehensive reference standard. Multivariate analysis showed that a combination of mural thickness and hyperenhancement best predicted active CD (area under the curve [AUC] = 0.92-0.93, P < 0.0001).


CONCLUSIONS
Lower radiation dose CTE exams are sensitive for the detection of active small bowel CD. The combination of mural thickness and hyperenhancement are the best radiologic predictors of active CD.
Siddiki
Hassan
H
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
Fletcher
Joel G
JG
Hara
Amy K
AK
Kofler
James M
JM
McCollough
Cynthia H
CH
Fidler
Jeff L
JL
Guimaraes
Luis
L
Huprich
James E
JE
Sandborn
William J
WJ
Loftus
Edward V
EV
Mandrekar
Jay
J
Bruining
David H
DH
D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007421:Intestine, Small / Q000000981:diagnostic imaging*; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed