HELICAL CT WITH ONLY COLONIC CONTRAST MATERIAL FOR DIAGNOSING DIVERTICULITIS - PROSPECTIVE EVALUATION OF 150 PATIENTS

OBJECTIVE. We prospectively evaluated a helical CT technique in which contrast material is administered only through the colon for the imagi ng of suspected diverticulitis. SUBJECTS AND METHODS. One hundred fift y consecutive patients who presented to our emergency department with clinically suspected diverticulitis underwent helical abdominal CT aft er contrast material was administered only through the colon. CT findi ngs of diverticulitis included diverticula, muscular wall hypertrophy, focal colonic wall thickening, and pericolonic fat stranding. CT resu lts were correlated with clinical follow-up (all patients) and with pa thologic findings (41 patients). RESULTS. A final clinical diagnosis o f diverticulitis was made in 64 patients (43%), of whom 62 (97%) had C T results positive for diverticulitis. Of the 86 patients for whom div erticulitis was clinically excluded, all (100%) had CT results that we re negative for diverticulitis CT interpretations had a sensitivity of 97%, a specificity of 100%, a positive predictive value of 100%, a ne gative predictive value of 98%, and an overall accuracy of 99%. Altern ative diagnoses were noted on CT in 50 (58%) of 86 patients who did no t have diverticulitis and included 50 (78%) of the 64 patients in whom an alternative condition other than nonspecific abdominal pain was es tablished. CONCLUSION. Helical CT obtained after contrast material adm inistered only through the colon is accurate (99%) for confirming or e xcluding clinically suspected diverticulitis and for suggesting altern ative conditions (78%) when they are present. This CT technique avoids the risks, discomforts, and costs of oral and IV contrast material ad ministration and allows immediate scanning.