Ultrasound 2D strain measurement for arm lymphedema using deformable registration: A feasibility study.

• Type of Material: Article
• Authors: Xiaofeng Yang, Emory University; Mylin Torres, Emory University; Stephanie Kirkpatrick, Emory University; Walter Curran, Emory University; Tian Liu, Emory University
• Language: English
• Date: 2017
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2017 Yang et al
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0181250
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 12
• Issue: 8
• Start Page: e0181250
• End Page: e0181250
• Grant/Funding Information: This research was supported in part by DOD PCRP Award W81XWH-13-1-0269, Dunwoody Golf Club Prostate Cancer Research Award, a philanthropic award provided by the Winship Cancer Institute of Emory University, and Susan Komen for the Cure foundation.; The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
• Research Categories: Health Sciences, Oncology; Health Sciences, Radiology

Abstract

PURPOSE: Lymphedema, a swelling of the extremity, is a debilitating morbidity of cancer treatment. Current clinical evaluation of lymphedema is often based on medical history and physical examinations, which is subjective. In this paper, the authors report an objective, quantitative 2D strain imaging approach using a hybrid deformable registration to measure soft-tissue stiffness and assess the severity of lymphedema. METHODS: The authors have developed a new 2D strain imaging method using registration of pre- and post-compression ultrasound B-mode images, which combines the statistical intensity- and structure-based similarity measures using normalized mutual information (NMI) metric and normalized sum-of-squared-differences (NSSD), with an affine-based global and B-spline-based local transformation model. This 2D strain method was tested through a series of experiments using elastography phantom under various pressures. Clinical feasibility was tested with four participants: two patients with arm lymphedema following breast-cancer radiotherapy and two healthy volunteers. RESULTS: The phantom experiments have shown that the proposed registration-based strain method significantly increased the signal-to-noise and contrast-to-noise ratio under various pressures as compared with the commonly used cross-correlation-based elastography method. In the pilot study, the strain images were successfully generated for all participants. The averaged strain values of the lymphedema affected arms were much higher than those of the normal arms. CONCLUSIONS: The authors have developed a deformable registration-based 2D strain method for the evaluation of arm lymphedema. The initial findings are encouraging and a large clinical study is warranted to further evaluate this 2D ultrasound strain imaging technology.