ISSN 0253-2778

CN 34-1054/N

open
Free to Publish. Free to Read.
Open AccessOpen Access JUSTC Life Sciences/ Engineering & Materials 20 April 2022

Sound speed imaging of small animal organs by ultrasound computed tomography

  • 1.

    Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230027, China

  • 2.

    Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230027, China

Cite this:
https://doi.org/10.52396/JUSTC-2021-0113
More Information
  • Author Bio:

    Zhiming Hu is a graduate student under the supervision of Prof. Chao Tian at the University of Science and Technology of China (USTC). His current research is focused on ultrasound computed tomography

    Chao Tian is a professor at the School of Engineering Science, University of Science and Technology of China (USTC). He received the B.S. degree in Electrical Engineering and the PhD degree in Optical Engineering from Zhejiang University, Hangzhou, China. From 2013 to 2017, he worked as a Post-Doctoral Research Fellow in photo-acoustic imaging with the Department of Biomedical Engineering at the University of Michigan, Ann Arbor. He has published over 40 peer-reviewed journal articles and is a co-inventor of six patents. Dr. Tian is a Senior Member of OSA and a member of SPIE and IEEE. His research interests focus on photo-acoustic and ultrasound imaging and their biomedical applications

  • Corresponding author: E-mail: ctian@ustc.edu.cn
  • Received Date: 20 April 2021
  • Accepted Date: 26 November 2021
    • Available Online: 20 April 2022
    Abstract

  • Abstract

    Sound speed is an important acoustic parameter for tissue characterization. Herein we developed an ultrasound computed tomography (USCT) system for ex vivo sound speed imaging and evaluation of small animal organs. The proposed USCT system employs a 256-element ring array transducer and allows simultaneous signal transmission and reception for all channels. The method does not require complicated sample preparation procedures and can yield accurate measurement results. Experimental results show that sound speeds of excised rat brain, heart, liver, spleen, and kidney measured by the method are close to published data. This work demonstrates a new method for sound speed imaging and holds potential for in vivo applications.

    Graphical abstract

      Sound speed imaging of small animal organs by ultrasound computed tomography

    Abstract

    Sound speed is an important acoustic parameter for tissue characterization. Herein we developed an ultrasound computed tomography (USCT) system for ex vivo sound speed imaging and evaluation of small animal organs. The proposed USCT system employs a 256-element ring array transducer and allows simultaneous signal transmission and reception for all channels. The method does not require complicated sample preparation procedures and can yield accurate measurement results. Experimental results show that sound speeds of excised rat brain, heart, liver, spleen, and kidney measured by the method are close to published data. This work demonstrates a new method for sound speed imaging and holds potential for in vivo applications.

    • Public Summary

    • An ultrasound computed tomography system with a 256-element ring array transducer was developed for sound speed imaging and evaluation of small animal organs.
    • Sound speeds of five excised rat organs were imaged and measured and the results are consistent to published data.
    • This work demonstrates a new method for sound speed imaging and holds potential for in vivo applications.

    FullText(HTML)
  • loading
    • References(38)
  • [1]
    Duck F A. Physical Properties of Tissues: a Comprehensive Reference Book. Academic Press, 1990. https://sciencedirect.53yu.com/book/9780122228001/physical-properties-of-tissues
    [2]
    Hachiya H, Ohtsuki S, Tanaka M. Relationship between speed of sound in and density of normal and diseased rat livers. Japanese Journal of Applied Physics, 1994, 33 (5S): 3130. doi: 10.1143/JJAP.33.3130
    [3]
    Ghoshal G, Lavarello R J, Kemmerer J P, et al. Ex vivo study of quantitative ultrasound parameters in fatty rabbit livers. Ultrasound in Medicine and Biology, 2012, 38 (12): 2238–2248. doi: 10.1016/j.ultrasmedbio.2012.08.010
    [4]
    Wiskin J, Malik B, Natesan R, et al. Quantitative assessment of breast density using transmission ultrasound tomography. Medical Physics, 2019, 46 (6): 2610–2620. doi: 10.1002/mp.13503
    [5]
    Zografos G, Liakou P, Koulocheri D, et al. Differentiation of BIRADS-4 small breast lesions via multimodal ultrasound tomography. European Radiology, 2015, 25 (2): 410–418. doi: 10.1007/s00330-014-3415-3
    [6]
    Bamber J C, Hill C R. Acoustic properties of normal and cancerous human liverjI. Dependence on pathological condition. Ultrasound in Medicine and Biology, 1981, 7 (2): 121–133. doi: 10.1016/0301-5629(81)90001-6
    [7]
    Li C, Duric N, Littrup P, et al. In Vivo breast sound-speed imaging with ultrasound tomography. Ultrasound in Medicine and Biology, 2009, 35 (10): 1615–1628. doi: 10.1016/j.ultrasmedbio.2009.05.011
    [8]
    Ruiter N V, Zapf M, Hopp T, et al. 3D ultrasound computer tomography of the breast: A new era? European Journal of Radiology, 2012, 81 (S): 133–134. doi: 10.1016/S0720-048X(12)70055-4
    [9]
    Ding M, Song J, Zhou L, et al. In Vitro and in Vivo evaluations of breast ultrasound tomography imaging system in HUST. Medical Imaging 2018— —4th World Congress on Medical Imaging and Clinical Research. London: International Society for Optics and Photonics, 2018: 105800P. https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10580/105800P/In-vitro-and-in-vivo-evaluations-of-breast-ultrasound-tomography/10.1117/12.2292985.short
    [10]
    Anderson M E, McKeag M S, Trahey G E. The impact of sound speed errors on medical ultrasound imaging. The Journal of the Acoustical Society of America, 2000, 107 (6): 3540–3548. doi: 10.1121/1.429422
    [11]
    Tian C, Zhang C, Zhang H, et al. Spatial resolution in photoacoustic computed tomography. Reports on Progress in Physics, 2021, 84 (3): 036701. doi: 10.1088/1361-6633/abdab9
    [12]
    Wang T, Liu W, Tian C. Combating acoustic heterogeneity in photoacoustic computed tomography: A review. Journal of Innovative Optical Health Sciences, 2020, 13 (03): 2030007. doi: 10.1142/S1793545820300074
    [13]
    Feng T, Zhu Y, Morris R, et al. Functional photoacoustic and ultrasonic assessment of osteoporosis: A clinical feasibility study. BME Frontiers, 2020, 2020: 1081540. doi: 10.34133/2020/1081540
    [14]
    Ophir J. Estimation of the speed of ultrasound propagation in biological tissues: A beam-tracking method. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1986, 33 (4): 359–368. doi: 10.1109/T-UFFC.1986.26843
    [15]
    Ophir J, Moriya T, Yazdi Y. A single transducer transaxial compression technique for the estimation of sound speed in biological tissues. Ultrasonic Imaging, 1991, 13 (3): 269–279. doi: 10.1177/016173469101300304
    [16]
    Yoon C, Lee Y, Chang J H, et al. In Vitro estimation of mean sound speed based on minimum average phase variance in medical ultrasound imaging. Ultrasonics, 2011, 51 (7): 795–802. doi: 10.1016/j.ultras.2011.03.007
    [17]
    Jakovljevic M, Hsieh S, Ali R, et al. Local speed of sound estimation in tissue using pulse-echo ultrasound: Model-based approach. The Journal of the Acoustical Society of America, 2018, 144 (1): 254–266. doi: 10.1121/1.5043402
    [18]
    Kondo M, Takamizawa K, Hirama M, et al. An evaluation of an in vivo local sound speed estimation technique by the crossed beam method. Ultrasound in Medicine and Biology, 1990, 16 (1): 65–72. doi: 10.1016/0301-5629(90)90087-S
    [19]
    Byram B C, Trahey G E, Jensen J A. A method for direct localized sound speed estimates using registered virtual detectors. Ultrasonic Imaging, 2012, 34 (3): 159–180. doi: 10.1177/0161734612455576
    [20]
    Robinson D E, Ophir J, Wilson L S, et al. Pulse-echo ultrasound speed measurements: progress and prospects. Ultrasound in Medicine and Biology, 1991, 17 (6): 633–646. doi: 10.1016/0301-5629(91)90034-T
    [21]
    Irie S, Inoue K, Yoshida K, et al. Speed of sound in diseased liver observed by scanning acoustic microscopy with 80 MHz and 250 MHz. The Journal of the Acoustical Society of America, 2016, 139 (1): 512–519. doi: 10.1121/1.4940126
    [22]
    Greenleaf J F, Johnson S A, Lee S L, et al. Algebraic reconstruction of spatial distributions of acoustic absorption within tissue from their two-dimensional acoustic projections. Acoustical Holography: Springer, 1974: 591–603. doi: 10.1007/978-1-4757-0827-1_34
    [23]
    PȦrez-Liva M, Herraiz J L, UdȪas J M, et al. Time domain reconstruction of sound speed and attenuation in ultrasound computed tomography using full wave inversion. The Journal of the Acoustical Society of America, 2017, 141 (3): 1595–1604. doi: 10.1121/1.4976688
    [24]
    Rajagopalan B, Greenleaf J F, Thomas P J, et al. Variation of acoustic speed with temperature in various excised human tissues studied by ultrasound computerized tomography. The Second International Symposium on Ultrasonic Tissue Characterization, (US Department of Commerce, National Bureau of Standards, 1979: 227. https://xs.dailyheadlines.cc/books?hl=zh-CN&lr=&id=AL7AirGJZfkC&oi=fnd&pg=PA227&ots=R-lsIWQxtU&sig=nEvwV5cHatxexxkatqdUEu0c-Fw
    [25]
    Del Grosso V A, Mader C W. Speed of sound in pure water. The Journal of the Acoustical Society of America, 1972, 52 (5B): 1442–1446. doi: 10.1121/1.1913258
    [26]
    Coppens A B. Simple equations for the speed of sound in Neptunian waters. The Journal of the Acoustical Society of America, 1981, 69 (3): 862–863. doi: 10.1121/1.385486
    [27]
    Li C, Huang L, Duric N, et al. An improved automatic time-of-flight picker for medical ultrasound tomography. Ultrasonics, 2009, 49 (1): 61–72. doi: 10.1016/j.ultras.2008.05.005
    [28]
    Ali R, Hsieh S, Dahl J. Open-source Gauss-Newton-based methods for refraction-corrected ultrasound computed tomography. Medical Imaging 2019, International Society for Optics and Photonics. London: SPIE, 2019: 1095508. https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10955/1095508/Open-source-Gauss-Newton-based-methods-for-refraction-corrected-ultrasound/10.1117/12.2511319.short?sessionGUID=329ad883-c9d9-02bc-9993-ced268bead49&sessionGUID=329ad883-c9d9-02bc-9993-ced268bead49&webSyncID=c89a0ce4-6e9e-6ec7-a49d-ab6a0cbad059
    [29]
    Aster R C, Borchers B, Thurber C H. Parameter Estimation and Inverse Problems. 3ed, Elsevier, 2018: 165. http://www.ees.nmt.edu/outside/courses/GEOP529/Docs/old/preface.pdf
    [30]
    Kuo I Y, Hete B, Shung K K. A novel method for the measurement of acoustic speed. The Journal of the Acoustical Society of America, 1990, 88 (4): 1679–1682. doi: 10.1121/1.400242
    [31]
    Kremkau F W, Barnes R W, McGraw C P. Ultrasonic attenuation and propagation speed in normal human brain. The Journal of the Acoustical Society of America, 1981, 70 (1): 29–38. doi: 10.1121/1.386578
    [32]
    Rabell-Montiel A, Thomson A J, Anderson T A, et al. Acoustic properties of small animal soft tissue in the frequency range 12~32 MHz. Ultrasound in Medicine and Biology, 2018, 44 (3): 702–713. doi: 10.1016/j.ultrasmedbio.2017.11.003
    [33]
    Hachiya H, Ohtsuki S. Non-contact measurement of sound speed of tissues. Ultrasonic Tissue Characterization, Springer, 1996: 63–72.
    [34]
    Chen C F, Robinson D E, Wilson L S, et al. Clinical sound speed measurement in liver and spleen in Vivo. Ultrasonic Imaging, 1987, 9 (4): 221–235.
    [35]
    Bamber J C, Hill C R. Ultrasonic attenuation and propagation speed in mammalian tissues as a function of temperature. Ultrasound in Medicine and Biology, 1979, 5 (2): 149–157. doi: 10.1016/0301-5629(79)90083-8
    [36]
    Sehgal C M, Brown G M, Bahn R C, et al. Measurement and use of acoustic nonlinearity and sound speed to estimate composition of excised livers. Ultrasound in Medicine and Biology, 1986, 12 (11): 865–874. doi: 10.1016/0301-5629(86)90004-9
    [37]
    Kumagai H, Yokoyama K, Katsuyama K, et al. A new method for measuring the speed of sound in rat liver ex vivo using an ultrasound system: Correlation of sound speed with fat deposition. Ultrasound in Medicine and Biology, 2014, 40 (10): 2499–2507. doi: 10.1016/j.ultrasmedbio.2014.03.019
    [38]
    Frizzell L A, Gindorf J D. Measurement of ultrasonic velocity in several biological tissues. Ultrasound in Medicine & Biology, 1981, 7 (4): 385–387. doi: 10.1016/0301-5629(81)90049-1
    • Supplements(0)
    • Related Articles
    • Track Citations
  • 加载中

Catalog

    Get Citation
    PDF
    XML

    Figure  1.  (a) Schematic showing the setup of the USCT imaging system. (b) Principle of bent-ray based image reconstruction. aij denotes the weight of the ith ray in the jth grid.

    Figure  2.  (a) Photograph of a gelatin phantom. (b) Sound speed image of a 22% gelatin phantom. (c) Comparison of average sound speeds of gelatin phantoms at mass concentrations from 14% to 30% measured by USCT and the pulse-echo method.

    Figure  3.  Sound speed maps of rat organs imaged by USCT. First column: photograph of isolated organs. Second column: corresponding sound speed maps. Third column: masks used to segment the regions of interest (ROIs). Fourth column: segmented images used to calculate the average sound speeds. First row to the fifth row: brain, heart, liver, spleen, kidney.

    Figure  4.  Histogram of a typical sound speed image. The histogram has two peaks. One peak represents the background (PBS buffer) and the other indicates the ROI.

    [1]
    Duck F A. Physical Properties of Tissues: a Comprehensive Reference Book. Academic Press, 1990. https://sciencedirect.53yu.com/book/9780122228001/physical-properties-of-tissues
    [2]
    Hachiya H, Ohtsuki S, Tanaka M. Relationship between speed of sound in and density of normal and diseased rat livers. Japanese Journal of Applied Physics, 1994, 33 (5S): 3130. doi: 10.1143/JJAP.33.3130
    [3]
    Ghoshal G, Lavarello R J, Kemmerer J P, et al. Ex vivo study of quantitative ultrasound parameters in fatty rabbit livers. Ultrasound in Medicine and Biology, 2012, 38 (12): 2238–2248. doi: 10.1016/j.ultrasmedbio.2012.08.010
    [4]
    Wiskin J, Malik B, Natesan R, et al. Quantitative assessment of breast density using transmission ultrasound tomography. Medical Physics, 2019, 46 (6): 2610–2620. doi: 10.1002/mp.13503
    [5]
    Zografos G, Liakou P, Koulocheri D, et al. Differentiation of BIRADS-4 small breast lesions via multimodal ultrasound tomography. European Radiology, 2015, 25 (2): 410–418. doi: 10.1007/s00330-014-3415-3
    [6]
    Bamber J C, Hill C R. Acoustic properties of normal and cancerous human liverjI. Dependence on pathological condition. Ultrasound in Medicine and Biology, 1981, 7 (2): 121–133. doi: 10.1016/0301-5629(81)90001-6
    [7]
    Li C, Duric N, Littrup P, et al. In Vivo breast sound-speed imaging with ultrasound tomography. Ultrasound in Medicine and Biology, 2009, 35 (10): 1615–1628. doi: 10.1016/j.ultrasmedbio.2009.05.011
    [8]
    Ruiter N V, Zapf M, Hopp T, et al. 3D ultrasound computer tomography of the breast: A new era? European Journal of Radiology, 2012, 81 (S): 133–134. doi: 10.1016/S0720-048X(12)70055-4
    [9]
    Ding M, Song J, Zhou L, et al. In Vitro and in Vivo evaluations of breast ultrasound tomography imaging system in HUST. Medical Imaging 2018— —4th World Congress on Medical Imaging and Clinical Research. London: International Society for Optics and Photonics, 2018: 105800P. https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10580/105800P/In-vitro-and-in-vivo-evaluations-of-breast-ultrasound-tomography/10.1117/12.2292985.short
    [10]
    Anderson M E, McKeag M S, Trahey G E. The impact of sound speed errors on medical ultrasound imaging. The Journal of the Acoustical Society of America, 2000, 107 (6): 3540–3548. doi: 10.1121/1.429422
    [11]
    Tian C, Zhang C, Zhang H, et al. Spatial resolution in photoacoustic computed tomography. Reports on Progress in Physics, 2021, 84 (3): 036701. doi: 10.1088/1361-6633/abdab9
    [12]
    Wang T, Liu W, Tian C. Combating acoustic heterogeneity in photoacoustic computed tomography: A review. Journal of Innovative Optical Health Sciences, 2020, 13 (03): 2030007. doi: 10.1142/S1793545820300074
    [13]
    Feng T, Zhu Y, Morris R, et al. Functional photoacoustic and ultrasonic assessment of osteoporosis: A clinical feasibility study. BME Frontiers, 2020, 2020: 1081540. doi: 10.34133/2020/1081540
    [14]
    Ophir J. Estimation of the speed of ultrasound propagation in biological tissues: A beam-tracking method. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1986, 33 (4): 359–368. doi: 10.1109/T-UFFC.1986.26843
    [15]
    Ophir J, Moriya T, Yazdi Y. A single transducer transaxial compression technique for the estimation of sound speed in biological tissues. Ultrasonic Imaging, 1991, 13 (3): 269–279. doi: 10.1177/016173469101300304
    [16]
    Yoon C, Lee Y, Chang J H, et al. In Vitro estimation of mean sound speed based on minimum average phase variance in medical ultrasound imaging. Ultrasonics, 2011, 51 (7): 795–802. doi: 10.1016/j.ultras.2011.03.007
    [17]
    Jakovljevic M, Hsieh S, Ali R, et al. Local speed of sound estimation in tissue using pulse-echo ultrasound: Model-based approach. The Journal of the Acoustical Society of America, 2018, 144 (1): 254–266. doi: 10.1121/1.5043402
    [18]
    Kondo M, Takamizawa K, Hirama M, et al. An evaluation of an in vivo local sound speed estimation technique by the crossed beam method. Ultrasound in Medicine and Biology, 1990, 16 (1): 65–72. doi: 10.1016/0301-5629(90)90087-S
    [19]
    Byram B C, Trahey G E, Jensen J A. A method for direct localized sound speed estimates using registered virtual detectors. Ultrasonic Imaging, 2012, 34 (3): 159–180. doi: 10.1177/0161734612455576
    [20]
    Robinson D E, Ophir J, Wilson L S, et al. Pulse-echo ultrasound speed measurements: progress and prospects. Ultrasound in Medicine and Biology, 1991, 17 (6): 633–646. doi: 10.1016/0301-5629(91)90034-T
    [21]
    Irie S, Inoue K, Yoshida K, et al. Speed of sound in diseased liver observed by scanning acoustic microscopy with 80 MHz and 250 MHz. The Journal of the Acoustical Society of America, 2016, 139 (1): 512–519. doi: 10.1121/1.4940126
    [22]
    Greenleaf J F, Johnson S A, Lee S L, et al. Algebraic reconstruction of spatial distributions of acoustic absorption within tissue from their two-dimensional acoustic projections. Acoustical Holography: Springer, 1974: 591–603. doi: 10.1007/978-1-4757-0827-1_34
    [23]
    PȦrez-Liva M, Herraiz J L, UdȪas J M, et al. Time domain reconstruction of sound speed and attenuation in ultrasound computed tomography using full wave inversion. The Journal of the Acoustical Society of America, 2017, 141 (3): 1595–1604. doi: 10.1121/1.4976688
    [24]
    Rajagopalan B, Greenleaf J F, Thomas P J, et al. Variation of acoustic speed with temperature in various excised human tissues studied by ultrasound computerized tomography. The Second International Symposium on Ultrasonic Tissue Characterization, (US Department of Commerce, National Bureau of Standards, 1979: 227. https://xs.dailyheadlines.cc/books?hl=zh-CN&lr=&id=AL7AirGJZfkC&oi=fnd&pg=PA227&ots=R-lsIWQxtU&sig=nEvwV5cHatxexxkatqdUEu0c-Fw
    [25]
    Del Grosso V A, Mader C W. Speed of sound in pure water. The Journal of the Acoustical Society of America, 1972, 52 (5B): 1442–1446. doi: 10.1121/1.1913258
    [26]
    Coppens A B. Simple equations for the speed of sound in Neptunian waters. The Journal of the Acoustical Society of America, 1981, 69 (3): 862–863. doi: 10.1121/1.385486
    [27]
    Li C, Huang L, Duric N, et al. An improved automatic time-of-flight picker for medical ultrasound tomography. Ultrasonics, 2009, 49 (1): 61–72. doi: 10.1016/j.ultras.2008.05.005
    [28]
    Ali R, Hsieh S, Dahl J. Open-source Gauss-Newton-based methods for refraction-corrected ultrasound computed tomography. Medical Imaging 2019, International Society for Optics and Photonics. London: SPIE, 2019: 1095508. https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10955/1095508/Open-source-Gauss-Newton-based-methods-for-refraction-corrected-ultrasound/10.1117/12.2511319.short?sessionGUID=329ad883-c9d9-02bc-9993-ced268bead49&sessionGUID=329ad883-c9d9-02bc-9993-ced268bead49&webSyncID=c89a0ce4-6e9e-6ec7-a49d-ab6a0cbad059
    [29]
    Aster R C, Borchers B, Thurber C H. Parameter Estimation and Inverse Problems. 3ed, Elsevier, 2018: 165. http://www.ees.nmt.edu/outside/courses/GEOP529/Docs/old/preface.pdf
    [30]
    Kuo I Y, Hete B, Shung K K. A novel method for the measurement of acoustic speed. The Journal of the Acoustical Society of America, 1990, 88 (4): 1679–1682. doi: 10.1121/1.400242
    [31]
    Kremkau F W, Barnes R W, McGraw C P. Ultrasonic attenuation and propagation speed in normal human brain. The Journal of the Acoustical Society of America, 1981, 70 (1): 29–38. doi: 10.1121/1.386578
    [32]
    Rabell-Montiel A, Thomson A J, Anderson T A, et al. Acoustic properties of small animal soft tissue in the frequency range 12~32 MHz. Ultrasound in Medicine and Biology, 2018, 44 (3): 702–713. doi: 10.1016/j.ultrasmedbio.2017.11.003
    [33]
    Hachiya H, Ohtsuki S. Non-contact measurement of sound speed of tissues. Ultrasonic Tissue Characterization, Springer, 1996: 63–72.
    [34]
    Chen C F, Robinson D E, Wilson L S, et al. Clinical sound speed measurement in liver and spleen in Vivo. Ultrasonic Imaging, 1987, 9 (4): 221–235.
    [35]
    Bamber J C, Hill C R. Ultrasonic attenuation and propagation speed in mammalian tissues as a function of temperature. Ultrasound in Medicine and Biology, 1979, 5 (2): 149–157. doi: 10.1016/0301-5629(79)90083-8
    [36]
    Sehgal C M, Brown G M, Bahn R C, et al. Measurement and use of acoustic nonlinearity and sound speed to estimate composition of excised livers. Ultrasound in Medicine and Biology, 1986, 12 (11): 865–874. doi: 10.1016/0301-5629(86)90004-9
    [37]
    Kumagai H, Yokoyama K, Katsuyama K, et al. A new method for measuring the speed of sound in rat liver ex vivo using an ultrasound system: Correlation of sound speed with fat deposition. Ultrasound in Medicine and Biology, 2014, 40 (10): 2499–2507. doi: 10.1016/j.ultrasmedbio.2014.03.019
    [38]
    Frizzell L A, Gindorf J D. Measurement of ultrasonic velocity in several biological tissues. Ultrasound in Medicine & Biology, 1981, 7 (4): 385–387. doi: 10.1016/0301-5629(81)90049-1
    Recommended articles
    TrendMD
    Volume 52 Issue 1 page: 8
    Cover

    Article Metrics

    Article views (1263) PDF downloads(5878)
    Proportional views

    Copyright © Editorial Office of JUSTC, All Rights Reserved. 皖ICP备05002528号

    Supported by: Beijing Renhe Information Technology Co. Ltd    

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return