HELICAL CT COMBINED WITH CONTRAST MATERIAL ADMINISTERED ONLY THROUGH THE COLON FOR IMAGING OF SUSPECTED APPENDICITIS

OBJECTIVE. Helical CT combined with contrast material administered by mouth and through the colon has been shown to be accurate for appendic eal imaging. This investigation was performed to determine if helical CT combined with contrast material administered only through the colon has comparable accuracy, SUBJECTS AND METHODS. One hundred patients p rospectively underwent appendiceal CT imaging with thin-collimation, h elical scanning limited to the lower abdomen and upper pelvis after co ntrast material was administered only through the colon. CT results we re correlated with surgical and pathologic findings at appendectomy (5 6 patients), other surgery (three patients), or clinical follow-up at least 2 months after the CT scan (41 patients). RESULTS. Fifty-three C T scans were interpreted as positive for appendicitis, including 52 tr ue-positives (with surgical-pathologic correlation) and one false-posi tive (with clinical follow-up). Forty-seven CT scans were interpreted as negative for appendicitis, including 40 true-negatives with clinica l follow-up, three true-negatives with appendectomy and pathologic cor relation, three true-negatives with other surgery and pathologic corre lation, and one false-negative with appendectomy and pathologic correl ation. CT had a 98% sensitivity, 98% specificity, 98% positive predict ive value, 98% negative predictive value, and 98% accuracy for diagnos ing or excluding appendicitis. In 47 normal appendix cases at CT, the appendix was seen in 44 cases (94%), and an alternative diagnosis was identified in 29 cases (62%). CONCLUSION. For diagnosing appendicitis, helical CT combined with contrast material administered only through the colon proved to be as accurate (98%) as helical CT combined with c ontrast material administered by mouth and through the colon. Helical CT with contrast material administered only through the colon also cou ld be performed immediately and without any of the potential patient r isks or discomforts of contrast material administered IV or by mouth.