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Published in: European Radiology 5/2018

01-05-2018 | Computed Tomography

Can We Perform CT of the Appendix with Less Than 1 mSv? A De-escalating Dose-simulation Study

Authors: Ji Hoon Park, Jong-June Jeon, Sung Soo Lee, Amar C. Dhanantwari, Ji Ye Sim, Hae Young Kim, Kyoung Ho Lee

Published in: European Radiology | Issue 5/2018

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Abstract

Objectives

To systematically explore the lowest reasonably achievable radiation dose for appendiceal CT using an iterative reconstruction (IR) in young adults.

Methods

We prospectively included 30 patients who underwent 2.0-mSv CT for suspected appendicitis. From the helical projection data, 1.5-, 1.0- and 0.5-mSv CTs were generated using a low-dose simulation tool and the knowledge-based IR. We performed step-wise non-inferiority tests sequentially comparing 2.0-mSv CT with each of 1.5-, 1.0- and 0.5-mSv CT, with a predetermined non-inferiority margin of 0.06. The primary end point was the pooled area under the receiver-operating-characteristic curve (AUC) for three abdominal and three non-abdominal radiologists.

Results

For the abdominal radiologists, the non-inferiorities of 1.5-, 1.0- and 0.5-mSv CT to 2.0-mSv CT were sequentially accepted [pooled AUC difference: 2.0 vs. 0.5 mSv, 0.017 (95% CI: -0.016, 0.050)]. For the non-abdominal radiologists, the non-inferiorities of 1.5- and 1.0-mSv CT were accepted; however, the non-inferiority of 0.5-mSv CT could not be proved [pooled AUC difference: 2.0 vs. 1.0 mSv, -0.017 (-0.070, 0.035) and 2.0 vs. 0.5 mSv, 0.045 (-0.071, 0.161)].

Conclusion

The 1.0-mSv appendiceal CT was non-inferior to 2.0-mSv CT in terms of diagnostic performance for both abdominal and non-abdominal radiologists; 0.5-mSv appendiceal CT was non-inferior only for abdominal radiologists.

Key points

• For both abdominal and non-abdominal radiologists, 1.0-mSv appendiceal CT could be feasible.
• The 0.5-mSv CT was non-inferior to 2.0-mSv CT only for expert abdominal radiologists.
• Reader experience is an important factor affecting diagnostic impairment by low-dose CT.
Appendix
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Metadata
Title
Can We Perform CT of the Appendix with Less Than 1 mSv? A De-escalating Dose-simulation Study
Authors
Ji Hoon Park
Jong-June Jeon
Sung Soo Lee
Amar C. Dhanantwari
Ji Ye Sim
Hae Young Kim
Kyoung Ho Lee
Publication date
01-05-2018
Publisher
Springer Berlin Heidelberg
Published in
European Radiology / Issue 5/2018
Print ISSN: 0938-7994
Electronic ISSN: 1432-1084
DOI
https://doi.org/10.1007/s00330-017-5159-3

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