The Role of Abdomen-pelvis CT for the Diagnosis of Appendicitis

ABSTRACT

PURPOSE: We wanted to evaluate the value of intravenous contrast enhanced abdomen-pelvis computed tomography (CT) for diagnosing acute appendicitis and we wanted to determine which patients groups will benefit from preoperative CT. METHODS: Between January and June 2006, the medical records of 354 patients who had clinically suspected acute appendicitis were retrospectively reviewed. Appendectomy was performed in 260 patients and CT was conducted in 108 patients of the 260 patients. The 5mm slice CT scans were evaluated for the presence of appendicitis. The sensitivity, specificity and accuracy of CT were calculated. The negative appendectomy rate (NAR) was compared between the patients with CT scans and those without CT scans. Furthermore, the patients were classified into the children and adults groups and the male and female groups and the differences of the NARs were analyzed for each group. RESULTS: The sensitivity, specificity and accuracy were 95%, 93% and 94%, respectively. The NAR was lower for the patients with a CT scan (12%) compared to 27% for those patients without CT scans (P=0.002). The difference of the NAR between the preoperative CT group and the without CT group was statistically significant for the female (P=0.004) and adult groups (P=0.012) (14% vs 36%, 11% vs 26%, respectively). CONCLUSION: Preoperative intravenous contrast enhanced abdomen-pelvis CT was effective in reducing the negative appendectomy rate in patients who were suspected of having acute appendicitis. Especially, the adults and women benefit more from CT scanning and they had a significantly lower negative appendectomy rate than the children and men, respectively.