RESEARCH ARTICLE
Stone heterogeneity index on single-energy noncontrast computed tomography can be a positive predictor of urinary stone composition Jong Soo Lee1, Kang Su Cho2, Seung Hwan Lee1, Young Eun Yoon3, Dong Hyuk Kang4, Won Sik Jeong5, Hae Do Jung6, Jong Kyou Kwon7, Joo Yong Lee1*
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1 Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea, 2 Department of Urology, Gangnam Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea, 3 Department of Urology, Hanyang University College of Medicine, Seoul, Korea, 4 Department of Urology, Inha University School of Medicine, Incheon, Korea, 5 Department of Urology, Kwangju Christian Hospital, Gwangju, Korea, 6 Department of Urology, Yongin Severance Hospital, Yonsei University Health System, Yongin, Korea, 7 Department of Urology, Severance Check-Up, Yonsei University Health System, Seoul, Korea *
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Abstract OPEN ACCESS Citation: Lee JS, Cho KS, Lee SH, Yoon YE, Kang DH, Jeong WS, et al. (2018) Stone heterogeneity index on single-energy noncontrast computed tomography can be a positive predictor of urinary stone composition. PLoS ONE 13(4): e0193945. https://doi.org/10.1371/journal.pone.0193945 Editor: Helen Wei Cui, University of Oxford, UNITED KINGDOM Received: June 20, 2017 Accepted: February 5, 2018 Published: April 12, 2018 Copyright: © 2018 Lee et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Data are restricted due to patients’ privacy and research ethics by the Severance Hospital and Urological Science Institution, Yonsei University College of Medicine Data Access and Ethics Committee. The release of patient data to the public would be a violation of IRB terms of approval. Qualifying researchers may apply for data access with Yonsei University College Institutional Review Board at
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The aim of this study was to investigate the correlation between stone composition and single-energy noncontrast computed tomography (NCCT) parameters, including stone heterogeneity index (SHI) and mean stone density (MSD), in patients with urinary calculi. We retrospectively reviewed medical records of 255 patients who underwent operations or procedures for urinary stones or had spontaneous stone passage between December 2014 and October 2015. Among these, 214 patients with urinary calculi who underwent NCCT and stone composition analyses were included in the study. Maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) were determined on pretreatment NCCT. The mean MSD (454.68±177.80 HU) and SHI (115.82±96.31 HU) of uric acid stones were lower than those of all other types. Based on post hoc tests, MSD was lower for uric acid stones than for the other types (vs. CaOx: P
