Low-dose CT for Diagnosing Appendicitis

Abstract

Research Article| October 01 2012 Low-dose CT for Diagnosing Appendicitis AAP Grand Rounds (2012) 28 (4): 41. https://doi.org/10.1542/gr.28-4-41 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Low-dose CT for Diagnosing Appendicitis. AAP Grand Rounds October 2012; 28 (4): 41. https://doi.org/10.1542/gr.28-4-41 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: appendicitis, low-dose spiral ct, appendectomy Source: Kim K, Kim YH, Kim SY, et al. Low-dose abdominal CT for evaluating suspected appendicitis. N Engl J Med. 2012; 366(17): 1596– 1605; doi: https://doi.org/10.1056/NEJMoa1110734Google Scholar Investigators in Seoul, Korea conducted a randomized, “noninferiority” study to determine if low-dose (2 mSv) CT is as accurate as standard-dose (8 mSv) CT in patients suspected of having acute appendicitis upon presentation to an emergency department (ED). Patients 15 to 44 years of age were enrolled when imaging was deemed necessary based on clinical signs and symptoms. They were randomly assigned to low- or standard-dose CT and all received IV contrast. Appendicitis was diagnosed based on pathology reports for participants who underwent surgery, and chart review plus phone follow-up 3 months after initial presentation for those who did not have surgery. The primary outcome was the rate of negative (unnecessary) appendectomy. The investigators defined a noninferiority margin of 5.5% for the difference in negative appendectomy rates (8% in low-dose vs 2.5% in standard-dose). This margin was chosen based on local experience and review of pertinent literature. A number of secondary outcomes were also assessed including time from CT to surgery, need for repeat imaging, appendiceal perforation rate, and length of stay (ED and hospital). Of 1,035 eligible patients, 891 (86%) were randomized and 879 completed the study (438 randomized to low-dose CT and 441 to standard-dose). Baseline characteristics were similar in patients assigned to the 2 groups. Appendicitis was confirmed in 38% (n=166) of the low-dose CT group and 41% (n=80) of the standard-dose CT group. The negative appendectomy rate was 3.5% (n=6) in the low-dose CT group and 3.2% (n=6) in the standard-dose CT group, a nonsignificant difference that met the criterion for noninferiority. Patients in the low-dose CT group waited longer between CT and surgery (median 7.1 hours vs 5.6 hours for those in the standard-dose group, P = .02) and were more likely to need additional imaging tests (3.2% and 1.6%, respectively; P = .09). Appendiceal perforation rate and length of stay (ED and hospital) were not different between the 2 groups. The authors conclude that low-dose CT is noninferior to standard-dose CT with respect to negative appendectomies in young adults. Dr Bordley has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. More than 10% of diagnostic imaging studies performed in developed countries are CT scans. Up to 7 million CT scans are performed on children in the United States every year.1 Even low-dose radiation exposure carries a small risk of cancer later in life, and this risk is magnified in children, in part because they have more years post-exposure in which to manifest an exposure-related neoplasm. Thus, the results of this study – that unnecessary appendectomies (false positive results) were not more frequent with low-dose compared with standard-dose CT scans – support a reduction in the radiation dose when CT... You do not currently have access to this content.