Related Experiment Video
Updated: Mar 8, 2026

Author Spotlight: Using Point-of-Care Ultrasound for Comprehensive Evaluation of the Abdominal Aorta
Published on: September 8, 2023
A new technique for the diagnosis of acute appendicitis: abdominal CT with compression to the right lower quadrant
Abidin Kılınçer1, Erhan Akpınar2, Bülent Erbil3
1Department of Radiology, Hacettepe University Faculty of Medicine, Sıhhiye, Ankara, 06100, Turkey.
Objective:
To determine the diagnostic accuracy of abdominal CT with compression to the right lower quadrant (RLQ) in adults with acute appendicitis.
Methods:
168 patients (age range, 18-78 years) were included who underwent contrast-enhanced CT for suspected appendicitis performed either using compression to the RLQ (n = 71) or a standard protocol (n = 97). Outer diameter of the appendix, appendiceal wall thickening, luminal content and associated findings were evaluated in each patient. Kruskal-Wallis, Fisher's and Pearson's chi-squared tests were used for statistical analysis.
Results:
There was no significant difference in the mean outer diameter (MOD) between compression CT scans (10.6 ± 1.9 mm) and standard protocol (11.2 ± 2.3 mm) in patients with acute appendicitis (P = 1). MOD was significantly lower in the compression group (5.2 ± 0.8 mm) compared to the standard protocol (6.5 ± 1.1 mm) (P < 0.01) in patients without appendicitis. A cut-off value of 6.75 mm for the outer diameter of the appendix was found to be 100% sensitive in the diagnosis of acute appendicitis for both groups. The specificity was higher for compression CT technique (67.7 vs. 94.9%).
Conclusion:
Normal appendix diameter was significantly smaller in the compression-CT group compared to standard-CT group, increasing diagnostic accuracy of abdominal compression CT.
Key Points:
• Normal appendix diameter is significantly smaller in compression CT. • Compression could force contrast material to flow through the appendiceal lumen. • Compression CT may be a CT counterpart of graded compression US.
Related Concept Videos
Appendicitis-I: Introduction
Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in...
Appendicitis-II: Diagnostic Studies and Management
Diagnosing Appendicitis
It requires a multifaceted approach, starting with a detailed physical examination to pinpoint the location and nature of the pain and identify any associated symptoms. Laboratory tests play a crucial role. A complete Blood Count (CBC) typically reveals leukocytosis (an increased number of...
Imaging Studies III: Computed Tomography
Abdominal Regions and Quadrants
The simpler quadrants approach, which is more commonly used in medicine, subdivides the cavity with one horizontal and one vertical line that intersects at the patient's umbilicus (navel). The four...
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Imaging Studies for Cardiovascular System V: CT

