Computed tomography criterion for the diagnosis of appendicitis without periappendiceal inflammation in children using the maximum depth of intraluminal appendiceal fluid.

Objective: The objective of this study was to evaluate whether maximum depth of intraluminal appendiceal fluid (DEPTH) is useful in differentiating appendicitis without periappendiceal inflammation from enlarged normal appendices in children.

Methods: We retrospectively evaluated 826 intravenously enhanced abdominal-pelvic computed tomographic examinations in children (aged 0-18 years) using the following criteria for appendicitis: (1) appendiceal wall thickness greater than 3 mm, (2) appendiceal wall enhancement, (3) focal cecal wall thickening, (4) adjacent adenopathy, (5) appendicolith, and (6) DEPTH. Of 826, 192 were classified into the noncomplicated-normal appendix group (85 enlarged normal appendices [diameter >6 mm] without adjacent lesions), the complicated-normal appendix group (44 enlarged normal appendices with adjacent lesions), or the our-appendicitis group (63 operatively proved appendicitis without periappendiceal inflammation).

Results: The criterion "DEPTH greater than 2.6 mm" determined by receiver operating characteristic analysis between our-appendicitis and complicated-normal appendix groups demonstrated both higher sensitivity and higher specificity in all groups (>90%). In contrast, the other criteria showed lower sensitivities (<58%) in our-appendicitis group.

Conclusions: The criterion "DEPTH greater than 2.6 mm" is particularly useful for differentiating appendicitis without periappendiceal inflammation from enlarged normal appendices in children.