Multidetector helical CT in the evaluation of acute small bowel obstruction: comparison of non-enhanced (no oral, rectal or IV contrast) and IV enhanced CT.
OBJECTIVE
To compare accuracy of non-enhanced CT (NECT) (no oral or IV contrast) and enhanced CT (ECT) (IV enhanced only) to diagnose small bowel obstruction and evaluate reviewer's experience impact.


METHODS
Ninety-nine adult patients underwent 105 NECT and ECT (6 patients had 2 examinations) on a four-detector CT. An abdominal radiologist, an abdominal imaging fellow, a second-year radiology resident retrospectively reviewed NECTs and ECTs separately and independently blinded to outcome. Discrepancy of diameter of proximal and distal small bowel+/-a transition was considered indication of mechanical bowel obstruction. Reference standard was surgery in 26 and chart review in 79.


RESULTS
Mechanical obstruction was present in 56% (59/105). The average sensitivity, specificity, negative and positive predictive and accuracy values for NECT were 88.1% (CI: 80-96%), 77% (CI: 65-89%), 83.0% (CI: 72-95%), 83% (CI: 74-92%), and 83% (CI: 76-90%) with no significant difference between three reviewers. The corresponding numbers for ECT were 87.6% (CI: 79-96%), 75% (CI: 63-88%), 82.6.0% (CI: 71-94%), 82.1% (CI: 73-92%), and 82% (CI: 75-90%) (p>0.5). Area under curve (AUC) of ROC curves of three reviewers did not show significant statistical difference (p>0.5).


CONCLUSIONS
NECT and ECT have comparable accuracy to diagnose mechanical small bowel obstruction and can be interpreted by reviewers with different levels of expertise.
Atri
Mostafa
M
Department of Medical Imaging, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ont. M5G 2N2, Canada. mostafa.atri@uhn.on.ca
McGregor
Caitlin
C
McInnes
Mathew
M
Power
Niall
N
Rahnavardi
Katayoun
K
Law
Calvin
C
Kiss
Alex
A
D000285:Administration, Rectal; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging*; D007421:Intestine, Small / Q000000981:diagnostic imaging*; D007472:Iohexol / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*; D055815:Young Adult
D003287:Contrast Media; D007472:Iohexol