CT Protocols for Acute Appendicitis: Time for Change

AJR:193, November 2009 optimal for imaging patients with suspected acute appendicitis. This is an important issue because IV contrast administration is associated with increased examination cost; increased patient discomfort; risk of allergic reaction [12]; risk of tissue injury if extravasation occurs [13]; and risk of renal insufficiency [14], which rarely occurs. Positive oral contrast ingestion is inconvenient for the patient and requires a delay to allow the ingested contrast medium to pass into the cecum [15]. During the time interval between the initial clinical evaluation and subsequent CT examination after oral contrast ingestion, patients might be at risk for appendiceal perforation. Furthermore, emergency departments are closely scrutinized to decrease length of stay. Standard-dose CT exposes patients to radiation, which is a concern particularly given that appendicitis is common, with a lifetime risk of 8.6% for men and 6.7% for women [16]; moreover, there is a trend toward increased use of CT [17], and many patients with suspected acute appendicitis are young [16]. If a low-dose protocol without IV or oral contrast material had an accuracy similar to that of the traditional protocol, patients with suspected acute appendicitis would benefit. Recent work highlighted in the AJR from Belgium [18], Korea [19], and the United States [20] provides compelling evidence that a low-radiation-dose protocol without oral or IV contrast material may be adequate for the diagnosis of acute appendicitis. The time for change may be upon us. Keyzer et al. [18] randomized patients to ingest or not ingest positive oral contrast medium. Thereafter, all patients underwent both unenhanced and IV contrast-enhanced scanning. CT Protocols for Acute Appendicitis: Time for Change