Non enhanced helical Ct scan in visualization of normal appendix

الملخص EN

Purpose : To evaluate the frequency of visualization, thickness, and anatomical features of the normal appendix at nonenhanced helical computed tomography (CT).

Materials and methods : Two radiologists prospectively iterpreted, in consensus, the abdominal CT scans of 140 patients who were examined for renal colic assessment.

They were blinded to patients' surgical history regarding a previous appendectomy.

No contrast material was used.

The frequency of visualization, and the two-wall thickness of normal appendix were recorded, as well as the anatomical features of the appendix and the effect of adequasy of intraperitoneal fat on identification of the appendix.

Results : The prevalence of appendectomy was 9 % (13 of 140 patients).

The sensitivity, specificity, positive and negative predictive values, and accurasy of visualization of normal appendix were 77 %, 85 %, 98 %, 27 %, and 77 % respectively.

The frequency of visualization was lower in patients with less nintraperitoneal fat.

The mean thickness of normal appendix if no intraluminal content was visualized was 6.6 mm + 1.

0 mm, and the mean thickness excluding visualized intraluminal content was 3.

6mm + 0.

8 mm.

Conclusion : Most normal appendices are seen at nonenhanced helical CT.

The thickness of normal appendix, when the content is not recognizable, overlaps the values currently used to diagnose appendicitis at CT.