Noninvasive evaluation of active lower gastrointestinal bleeding: comparison between contrast-enhanced MDCT and 99mTc-labeled RBC scintigraphy.
OBJECTIVE
The purpose of our study was to compare contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning for the evaluation of active lower gastrointestinal bleeding.


METHODS
Over 17 months, 55 patients (32 men, 23 women; age range, 21-92 years) were evaluated prospectively with contrast-enhanced MDCT using 100 mL of iopromide 300 mg I/mL. Technetium-99m-labeled RBC scans were obtained on 41 of 55 patients and select patients underwent angiography for attempted embolization. Each imaging technique was reviewed in a blinded fashion for sensitivity for detection of active bleeding as well as the active lower gastrointestinal bleeding location.


RESULTS
Findings were positive on both examinations in eight patients and negative on both examinations in 20 patients. Findings were positive on contrast-enhanced MDCT and negative on (99m)Tc-labeled RBC in two patients; findings were negative on contrast-enhanced MDCT and positive on (99m)Tc-labeled RBC in 11 patients. Statistics showed significant disagreement, with simple agreement = 68.3%, kappa = 0.341, and p = 0.014. Sixteen of 60 (26.7%) contrast-enhanced MDCT scans were positive prospectively, with all accurately localizing the site of bleeding and identification of the underlying lesion in eight of 16 (50%). Nineteen of 41 (46.3%) (99m)Tc-labeled RBC scans were positive. Eighteen of 41 matched patients went on to angiography. In four of these 18 (22.2%) patients, the site of bleeding was confirmed by angiography, but in 14 of 18 (77.8%), the findings were negative.


CONCLUSIONS
Contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning show significant disagreement for evaluation of active lower gastrointestinal bleeding. Contrast-enhanced MDCT appears effective for detection and localization in cases of active lower gastrointestinal bleeding in which hemorrhage is active at the time of CT.
Zink
Stephen I
SI
Department of Radiology, Hartford Hospital, Hartford, CT, USA.
Ohki
Stephen K
SK
Stein
Barry
B
Zambuto
Domenic A
DA
Rosenberg
Ronald J
RJ
Choi
Jenny J
JJ
Tubbs
Daniel S
DS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D004912:Erythrocytes / Q000000981:diagnostic imaging*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000000981:diagnostic imaging*; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D041741:Lower Gastrointestinal Tract / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013667:Technetium; D014055:Tomography, Emission-Computed / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D019275:Radiopharmaceuticals; D007472:Iohexol; C038192:iopromide; D013667:Technetium