Patrick M. Rao

Sensitivity and specificity of the individual CT signs of appendicitis : Experience with 200 helical appendiceal CT examinations

PURPOSE Our goal was to determine the sensitivity, specificity, and diagnostic value of individual signs at helical appendiceal CT. METHOD Two hundred helical appendiceal CT scans (100 appendicitis and 100 normal appendix cases) were interpreted for individual signs of appendicitis. Scan findings were correlated with appendectomy or clinical follow-up results. RESULTS Individual CT signs identified and their sensitivity and specificity, respectively, included fat stranding (100%, 80%), enlarged (> 6 mm) unopacified appendix (93%, 100%), focal cecal apical thickening (69%, 100%), adenopathy (62%, 66%), appendolith(s) (44%, 100%), arrowhead sign (23%, 100%), paracolic gutter fluid (18%, 86%), abscess (11%, 100%), cecal bar (10%, 100%), extraluminal air (8%, 97%), phlegmon (7%, 99%), ileal (3%, 86%) or sigmoid (3%, 95%) wall thickening, and diffuse cecal wall thickening (0%, 91%). CONCLUSION Individual appendiceal CT signs of appendicitis vary in sensitivity, specificity, and thus diagnostic value. An enlarged appendix with periappendiceal fat stranding occurs in 93% of appendicitis CT cases. Less common but specific signs [cecal apical changes, appendolith(s) are usually present in the remaining appendicitis cases. Some signs seen with appendicitis (adenopathy, fat stranding, adjacent bowel wall thickening, fluid) can also be noted with alternative conditions, and in these cases normal appendix identification is the key to excluding appendicitis.

Imaging of acute right lower abdominal quadrant pain.

This article reviews the clinical diagnosis of appendicitis, indications and options for appendiceal imaging, compares appendiceal CT techniques, and describes the imaging findings with appendicitis and alternative conditions that can clinically mimic appendicitis.

Helical CT of appendicitis and diverticulitis.

The clinical diagnosis of appendicitis and diverticulitis remains challenging. Clinical diagnosis alone can lead to unnecessary hospitalizations and surgeries, prolonged periods of hospital observation, and delays prior to necessary medical or surgical treatment. Helical CT combined with recently reported techniques for imaging appendicitis and diverticulitis offers rapid and accurate confirmation or exclusion of these entities as well as identification of alternative conditions that can clinically mimic them. More routine use of helical CT holds great promise for improving patient care and lowering hospital resource use in patients with clinically suspected appendicitis and diverticulitis.

Cecal apical changes with appendicitis : Diagnosing appendicitis when the appendix is borderline abnormal or not seen

In most cases, CT of appendicitis shows a distended appendix with periappendiceal inflammation. A distended appendix, however, is not always visualized. In these patients, identifying changes at the anatomic cecal apex can secure a diagnosis of appendicitis. Cecal apical changes with appendicitis include focal cecal apical thickening, the arrowhead sign, and the cecal bar. This pictorial essay describes and illustrates the spectrum of CT appearances of cecal apical changes that can be seen with appendicitis.