Tomohiro Yokoyama1, Shohei Mori2, Mototaka Arakawa3,4, Eiko Onishi5, Masanori Yamauchi5, Hiroshi Kanai1,2. 1. Graduate School of Biomedical Engineering, Tohoku University, Sendai, 980-8579, Japan. 2. Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan. 3. Graduate School of Biomedical Engineering, Tohoku University, Sendai, 980-8579, Japan. arakawa@ecei.tohoku.ac.jp. 4. Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan. arakawa@ecei.tohoku.ac.jp. 5. Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, 980-8575, Japan.
Abstract
PURPOSE: Medical ultrasound is often used to specify the puncture position during epidural anesthesia. However, visualization of the thoracic spine is difficult because of the complex structure, i.e., it is difficult to determine whether the thoracic spine or muscle is depicted. Therefore, this study aims to distinguish bone from muscle tissue using the differences in reflection and scattering characteristics of ultrasound. METHODS: We experimentally investigated the difference in signals received from bone and muscle. We proposed a new parameter utilizing the ratio of the amplitude of the received signals averaged in a wide range around the ideal delay line and that only along the ideal delay line, to emphasize the bone. RESULTS: First, we confirmed the difference in signals received from bone and muscle tissue by basic experiments. We also investigated the difference by in vitro experiments using chicken thigh and in vivo experiments in humans. In both experiments, the proposed method succeeded to clearly depict bone, suppressing the depiction of muscle, compared with conventional B-mode imaging. CONCLUSION: Using the difference in the characteristics of reflection from bone and scattering from muscle tissue, we could distinguish bone from muscle tissue with the proposed method.
PURPOSE: Medical ultrasound is often used to specify the puncture position during epidural anesthesia. However, visualization of the thoracic spine is difficult because of the complex structure, i.e., it is difficult to determine whether the thoracic spine or muscle is depicted. Therefore, this study aims to distinguish bone from muscle tissue using the differences in reflection and scattering characteristics of ultrasound. METHODS: We experimentally investigated the difference in signals received from bone and muscle. We proposed a new parameter utilizing the ratio of the amplitude of the received signals averaged in a wide range around the ideal delay line and that only along the ideal delay line, to emphasize the bone. RESULTS: First, we confirmed the difference in signals received from bone and muscle tissue by basic experiments. We also investigated the difference by in vitro experiments using chicken thigh and in vivo experiments in humans. In both experiments, the proposed method succeeded to clearly depict bone, suppressing the depiction of muscle, compared with conventional B-mode imaging. CONCLUSION: Using the difference in the characteristics of reflection from bone and scattering from muscle tissue, we could distinguish bone from muscle tissue with the proposed method.
Authors: Hedyeh Rafii-Tari; Victoria A Lessoway; Allaudin A Kamani; Purang Abolmaesumi; Robert Rohling Journal: Ultrasound Med Biol Date: 2015-05-08 Impact factor: 2.998