Appendiceal Visualization on 2-mSv CT vs. Conventional-Dose CT in Adolescents and Young Adults with Suspected Appendicitis: An Analysis of Large Pragmatic Randomized Trial Data

Jungheum Cho; Youngjune Kim; Seungjae Lee; Hooney Daniel Min; Yousun Ko; Choong Guen Chee; Hae Young Kim; Ji Hoon Park; Kyoung Ho Lee; LOCAT Group

doi:10.3348/kjr.2021.0504

Appendiceal Visualization on 2-mSv CT vs. Conventional-Dose CT in Adolescents and Young Adults with Suspected Appendicitis: An Analysis of Large Pragmatic Randomized Trial Data

Korean J Radiol. 2022 Apr;23(4):413-425. doi: 10.3348/kjr.2021.0504. Epub 2022 Jan 27.

Authors

Jungheum Cho¹, Youngjune Kim², Seungjae Lee³, Hooney Daniel Min¹, Yousun Ko⁴, Choong Guen Chee⁵, Hae Young Kim¹, Ji Hoon Park^{1

3

6}, Kyoung Ho Lee^{1

3

6

7}; LOCAT Group

Affiliations

¹ Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.
² Aerospace Medical Group, Air Force Education and Training Command, Jinju, Korea.
³ Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.
⁴ Biomedical Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea.
⁵ Department of Radiology, Asan Medical Center, Seoul, Korea.
⁶ Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
⁷ Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, Korea. kholeemail@gmail.com.

Abstract

Objective: We compared appendiceal visualization on 2-mSv CT vs. conventional-dose CT (median 7 mSv) in adolescents and young adults and analyzed the undesirable clinical and diagnostic outcomes that followed appendiceal nonvisualization.

Materials and methods: A total of 3074 patients aged 15-44 years (mean ± standard deviation, 28 ± 9 years; 1672 female) from 20 hospitals were randomized to the 2-mSv CT or conventional-dose CT group (1535 vs. 1539) from December 2013 through August 2016. A total of 161 radiologists from 20 institutions prospectively rated appendiceal visualization (grade 0, not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized) and the presence of appendicitis in these patients. The final diagnosis was based on CT imaging and surgical, pathologic, and clinical findings. We analyzed undesirable clinical or diagnostic outcomes, such as negative appendectomy, perforated appendicitis, more extensive than simple appendectomy, delay in patient management, or incorrect CT diagnosis, which followed appendiceal nonvisualization (defined as grade 0 or 1) and compared the outcomes between the two groups.

Results: In the 2-mSv CT and conventional-dose CT groups, appendiceal visualization was rated as grade 0 in 41 (2.7%) and 18 (1.2%) patients, respectively; grade 1 in 181 (11.8%) and 81 (5.3%) patients, respectively; and grade 2 in 1304 (85.0%) and 1421 (92.3%) patients, respectively (p < 0.001). Overall, undesirable outcomes were rare in both groups. Compared to the conventional-dose CT group, the 2-mSv CT group had slightly higher rates of perforated appendicitis (1.1% [17] vs. 0.5% [7], p = 0.06) and false-negative diagnoses (0.4% [6] vs. 0.0% [0], p = 0.01) following appendiceal nonvisualization. Otherwise, these two groups were comparable.

Conclusion: The use of 2-mSv CT instead of conventional-dose CT impairs appendiceal visualization in more patients. However, appendiceal nonvisualization on 2-mSv CT rarely leads to undesirable clinical or diagnostic outcomes.

Keywords: Abdomen; Appendicitis; Radiation dosage; Tomography, X-ray computed.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Appendectomy
Appendicitis* / diagnostic imaging
Appendicitis* / surgery
Appendix* / diagnostic imaging
Female
Humans
Radiologists
Tomography, X-Ray Computed / methods
Young Adult