Impact in the emergency department of unenhanced CT on diagnostic confidence and therapeutic efficacy in patients with suspected renal colic: A prospective survey

OBJECTIVE. Our objective was to evaluate the impact of unenhanced CT on cli nician diagnostic confidence and therapeutic efficacy in emergency departme nt patients with clinically suspected renal colic. SUBJECTS AND METHODS. Questionnaires were completed on 93 patients who were referred to the radiology department with clinically suspected renal colic . We prospectively surveyed the clinician's diagnostic confidence and treat ment plan before and after unenhanced abdominal and pelvic CT. RESULTS. Fifty-six patients (60%) had positive findings for calculi, 20 pat ients (22%) had normal findings, and alternative diagnoses were found in 17 patients (18%). The clinician's diagnostic certainty of stones before CT w as variable with the largest frequencies at 41-60% (n = 30) and 71-90% (n = 35). The diagnostic certainty of stones after CT showed movement toward ei ther less than or equal to 10% (n = 25) or greater than or equal to 91% (n = 51). The mean change in diagnostic confidence was 34%. Fifty-seven patien ts (61%) had a change in treatment plan. Specifically, the need for urology consultation as the initial treatment plan was reduced from 24 patients to one patient. Plans for admissions suggested before CT (n = 11) were nearly cut in half (n = 6) after imaging. Lastly, seven patients who would have i nitially been discharged were admitted to the hospital after imaging. CONCLUSION. CT significantly increased emergency department clinician diagn ostic confidence and altered initial treatment decisions in patients with s uspected renal colic. Most often, CT confirmed a ureteral stone and allowed appropriate discharge or urologic intervention. In a smaller subset of pat ients, CT established a significant alternative diagnosis that allowed the prompt initiation of appropriate treatment.