Current Concepts in Imaging of Appendicitis

Acute Appendicitis – Propedeutics and Diagnosis

“…This region is also known as McBurney's point. [2] The various positions of the appendix are conveniently categorized into the following locations: [5,8,18] -paracolic -the appendix lies in the right paracolic gutter lateral to the caecum (35 %); -retrocaecal -the appendix lies posterior to the caecum and may be partially or totally extraperitoneal (30 %); -preileal -the appendix is anterior to the terminal ileum (1,5 %); -postileal -the appendix is posterior to the ileum (1,5 %); -promontoric -the tip of the appendix lies in the vicinity of the sacral promontory (1%); -pelvic -the tip of the appendix lies in or toward the pelvis (30%); -subcaecal -the appendix lies inferior to the caecum (1 %). This variability in location may greatly influence the clinical presentation in patients with appendicitis.…”

“…A more recent imaging-based study showed that in only 4% is the appendix located at the classic McBurney point (the junction of the lateral and middle third of the line between the anterior superior iliac spine and the umbilicus). [5,8,18] …”

Imaging in Suspected Appendicitis

“…Note that these figures were based on data collected during 1979-1984 at a time when cross-sectional imaging technology was only burgeoning, but it illustrates well the concern practitioners had about the morbidity and mortality of a ruptured or perforated appendicitis. The mortality rate of a complicated appendicitis had reached 3% and about 47% of patients experienced significant morbidity [3], which led to the accepted general notion that a negative appendectomy rate of 20% was acceptable with its much lower morbidity to balance the higher risks associated with perforation. Overall, an estimated 36 incidental procedures are performed to prevent one future case of appendicitis.…”

Impact of the Increased Use of Preoperative Imaging and Laparoscopy on Appendicectomy Outcomes

“…Most institutions use ultrasound as the initial imaging modality, followed by CT if sonographic diagnosis is uncertain. This approach seems to have excellent accuracy, with reported sensitivity of 94-99 % and specificity of 94-95 % [4].…”

“…to diagnose the condition and the patient cannot be put through a computed tomography (CT) scanner because of renal failure/adverse effects of radiation (pregnancy) [4].…”