剪切波成像作為一種非侵入式超音波技術，用於評估肝纖維化、乳腺病變以及心肌組織的硬度等。然而使用傳統的聲輻射力脈衝(ARFI)推動組織產生剪切波體積成像的技術，面臨彈性影像視野有限的挑戰。本研究提出了使用聲漩渦波形(Vortex)來誘導剪切波成像，Vortex是具有螺旋相位結構的聲波，其聲波波前產生的破壞性干涉使其在橫向聲場呈現環狀分佈，進而在一個週期內產生四個剪切波源，誘導建設性干涉剪切波以增加對組織的軸向粒子位移量。使用Verasonics Vantage系統與121元件之二維陣列(2D array)探頭實現了Vortex推動模式，並將傳統的ARFI和Vortex推動脈衝進行了比較。實驗使用均質明膠-瓊脂仿體模擬背景，並於其中嵌入一個硬度較高的圓柱形嵌入物模擬異質區，剪切波在其中傳播速度為2.5 m/s，楊氏模量值為12.5 kPa。結果顯示，與ARFI相比，Vortex形成的建設性干涉剪切波源，可以增加約5.7 倍的組織位移量。對嵌入物的彈性影像對比雜訊比(CNR)提高了約8.7 dB，顯示出更好的對比度及辨別異質區域的能力。從與機械效應及熱效應相關的參數來看，Vortex只需要約一半的空間峰值平均時間強度(Ispta)就能得到比ARFI更高的彈性影像CNR值。通過超音波體積成像重建了以楊氏模量量化之體積彈性影像，相比傳統的ARFI，顯著改善了彈性影像的品質。Vortex作為推動脈衝誘導的剪切波體積成像，提供了穿透深度的優勢，並改善了使用2D array對各種疾病的診斷和治療。這項研究證明，利用Vortex技術產生的剪切波成像具有更大的組織位移量、更高的彈性影像對比度以及更小的能量需求，顯示出顯著的潛力和優勢。

Shear wave imaging, as a non-invasive ultrasound technique, is used to assess liver fibrosis, breast lesions, and myocardial tissue stiffness. However, the traditional Acoustic Radiation Force Impulse (ARFI) technique for generating shear wave volume imaging faces challenges in limited elastic imaging field of view. This study proposes the use of Vortex-generated shear wave imaging. Vortex is an acoustic wave with a spiral phase structure. Destructive interference generated by the acoustic wavefront creates a circular distribution in the lateral sound field, leading to the formation of four shear wave sources within one cycle, inducing constructive interference shear waves to increase axial particle displacement in the tissue. Vortex propulsion mode was implemented using the Verasonics Vantage system with a 2D array probe comprising 121 elements. Traditional ARFI and Vortex propulsion pulses were compared. Experiments were conducted using a homogeneous gelatin-agar phantom to simulate the background, with a higher hardness cylindrical inclusion mimicking a heterogeneous region embedded within it. The shear wave propagated at a speed of 2.5 meters/second with a Young's modulus of 12.5 kPa. Results showed that compared to ARFI, the constructive interference shear wave sources generated by Vortex increased tissue displacement by approximately 5.7 times. The Contrast-to-Noise Ratio (CNR) of the elastic image for the inclusion increased by about 8.7 dB, demonstrating better contrast and the ability to discriminate heterogeneous regions. From parameters related to mechanical and thermal effects, Vortex achieved a higher elastic image CNR value with approximately half of the spatial peak temporal average intensity (Ispta) of ARFI. Volume elastic images quantified by Young's modulus were reconstructed through ultrasound volume imaging, significantly improving image quality compared to traditional ARFI. Vortex, as a propulsion-induced shear wave volume imaging technique, offers advantages in penetration depth and enhances the diagnosis and treatment of various diseases using a 2D array. This study demonstrates that shear wave imaging generated by Vortex technology possesses larger tissue displacement, higher elastic image contrast, and lower energy requirements, showing significant potential and advantages.

摘要 i
Abstract ii
誌謝 iv
目錄 v
表目錄 vii
圖目錄 viii
第一章 緒論 1
1.1 超音波彈性成像 1
1.1.1 彈性成像診斷病變組織 1
1.1.2 超音波彈性成像之原理 2
1.2 超音波彈性成像技術 5
1.2.1 應變彈性成像 5
1.2.2 基於聲輻射力之彈性成像技術與其限制 5
1.3 聲漩渦式超音波技術 11
1.3.1 聲漩渦的特性與應用 11
1.3.2 聲漩渦波形誘導剪切波成像的潛力與優勢 12
1.4 研究目的及論文架構 13
第二章 實驗材料與方法 16
2.1 概論 16
2.2 超音波硬體設備 16
2.2.1 二維陣列式超音波探頭 16
2.2.2 Verasonics開放式研究系統 17
2.3 剪切波採集序列之設定 18
2.3.1 推動脈衝之設定 19
2.3.2 成像脈衝之設定 20
2.4 建設性干涉剪切波的模擬 21
2.4.1 聲場模擬 22
2.4.2 剪切波傳播模擬 23
2.5 實驗架構 25
2.5.1 聲場量測實驗 25
2.5.2 均質仿體實驗 25
2.5.3 均質仿體的製備 26
2.5.4 異質仿體實驗 27
2.6 數據處理與分析 28
2.6.1 軸向粒子速度之演算法 28
2.6.2 方向濾波器 30
2.6.3 計算剪切波速度之演算法 30
2.6.4 彈性影像之計算 31
第三章 實驗結果與討論 32
3.1 聲場的模擬與實際量測結果 32
3.2 建設性干涉剪切波的產生機制 34
3.2.1 聲輻射力分佈 35
3.2.2 剪切波源的分佈 36
3.2.3 剪切波波前傳播 36
3.2.4 建設性干涉剪切波增加的軸向位移 38
3.3 剪切波彈性成像 39
3.3.1 建設性干涉剪切波對軸向位移之貢獻 41
3.3.2 建設性干涉剪切波識別異質區域之能力 44
3.4 影響建設性干涉剪切波之參數 48
3.4.1 聚焦深度 48
3.4.2 剪切波源位置 50
第四章 結論與未來展望 54
4.1 結論 54
4.2 未來應用與發展 54
4.2.1 二維陣列式探頭誘導建設性干涉剪切波的意義與潛在應用 54
4.2.2 未來的研究方向 56
4.2.2.1 三維剪切波成像之彈性影像結果 56
參考文獻 58
附錄Ⅰ、剪切波系統測試 63

1. Ophir, J., et al., Elastography - a Quantitative Method for Imaging the Elasticity of Biological Tissues. Ultrasonic Imaging, 1991. 13(2): p. 111-134.
2. Sarvazyan, A.P., et al., Shear wave elasticity imaging: a new ultrasonic technology of medical diagnostics. Ultrasound in medicine & biology, 1998. 24(9): p. 1419-1435.
3. Castéra, L., et al., Prospective comparison of transient elastography, Fibrotest, APRI, and liver biopsy for the assessment of fibrosis in chronic hepatitis C. Gastroenterology, 2005. 128(2): p. 343-350.
4. Tanter, M., et al., Quantitative assessment of breast lesion viscoelasticity: initial clinical results using supersonic shear imaging. Ultrasound in medicine & biology, 2008. 34(9): p. 1373-1386.
5. Duck, F., Physical properties of tissues: a comprehensive reference book. 2013: Academic press.
6. Greenleaf, J.F., M. Fatemi, and M. Insana, Selected methods for imaging elastic properties of biological tissues. Annual review of biomedical engineering, 2003. 5(1): p. 57-78.
7. Frulio, N. and H. Trillaud, Ultrasound elastography in liver. Diagnostic and interventional imaging, 2013. 94(5): p. 515-534.
8. Shiina, T., et al., WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 1: basic principles and terminology. Ultrasound Med Biol, 2015. 41(5): p. 1126-47.
9. Cosgrove, D., et al., EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 2: Clinical applications. Ultraschall in der Medizin-European Journal of Ultrasound, 2013. 34(03): p. 238-253.
10. Caenen, A., et al., Assessing cardiac stiffness using ultrasound shear wave elastography. Physics in Medicine & Biology, 2022. 67(2): p. 02TR01.
11. Ferraioli, G., et al., WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver. Ultrasound in medicine & biology, 2015. 41(5): p. 1161-1179.
12. McDonagh, T.A., et al., 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. European Heart Journal, 2021. 42(36): p. 3599-3726.
13. Villemain, O., et al., Myocardial Stiffness Evaluation Using Noninvasive Shear Wave Imaging in Healthy and Hypertrophic Cardiomyopathic Adults. Jacc-Cardiovascular Imaging, 2019. 12(7): p. 1135-1145.
14. Dietrich, C.F., et al., EFSUMB guidelines and recommendations on the clinical use of liver ultrasound elastography, update 2017 (long version). Ultraschall in der Medizin-European Journal of Ultrasound, 2017. 38(04): p. e16-e47.
15. Sigrist, R.M.S., et al., Ultrasound Elastography: Review of Techniques and Clinical Applications. Theranostics, 2017. 7(5): p. 1303-1329.
16. Ophir, J., et al., Elastography: ultrasonic estimation and imaging of the elastic properties of tissues. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 1999. 213(3): p. 203-233.
17. Palmeri, M.L. and K.R. Nightingale, What challenges must be overcome before ultrasound elasticity imaging is ready for the clinic? Imaging in medicine, 2011. 3(4): p. 433.
18. D’Onofrio, M., et al., Acoustic radiation force impulse of the liver. World journal of gastroenterology: WJG, 2013. 19(30): p. 4841.
19. Bercoff, J., M. Tanter, and M. Fink, Supersonic shear imaging: A new technique for soft tissue elasticity mapping. Ieee Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2004. 51(4): p. 396-409.
20. Sandrin, L., et al., Time-resolved pulsed elastography with ultrafast ultrasonic imaging. Ultrasonic imaging, 1999. 21(4): p. 259-272.
21. Sandrin, L., et al., Shear modulus imaging with 2-D transient elastography. IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 2002. 49(4): p. 426-435.
22. Muller, M., et al., Quantitative Viscoelasticity Mapping of Human Liver Using Supersonic Shear Imaging: Preliminary. Vivo.
23. Tian, J., et al., Application of 3D and 2D quantitative shear wave elastography (SWE) to differentiate between benign and malignant breast masses. Scientific Reports, 2017. 7(1): p. 41216.
24. Aleef, T.A., et al., Multi-Frequency 3D Shear Wave Absolute Vibro-Elastography (S-WAVE) System for the Prostate. IEEE Transactions on Medical Imaging, 2023.
25. Lee, S.H., et al., Differentiation of benign from malignant solid breast masses: comparison of two-dimensional and three-dimensional shear-wave elastography. European radiology, 2013. 23: p. 1015-1026.
26. Fenster, A. and D.B. Downey, 3-D ultrasound imaging: A review. IEEE Engineering in Medicine and Biology magazine, 1996. 15(6): p. 41-51.
27. Prager, R.W., et al., Three-dimensional ultrasound imaging. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2010. 224(2): p. 193-223.
28. Provost, J., et al., 3D ultrafast ultrasound imaging in vivo. Physics in Medicine and Biology, 2014. 59(19): p. L1-L13.
29. Gennisson, J.-l., et al., 4-D ultrafast shear-wave imaging. IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 2015. 62(6): p. 1059-1065.
30. Dong, Z., et al., Three-dimensional Shear Wave Elastography Using a 2D Row Column Addressing (RCA) Array. BME Frontiers, 2022. 2022.
31. Zeng, Q., et al., Three-dimensional multi-frequency shear wave absolute vibro-elastography (3D S-WAVE) with a matrix array transducer: implementation and preliminary in vivo study of the liver. IEEE Transactions on Medical Imaging, 2020. 40(2): p. 648-660.
32. Zeng, Q., et al. 3D liver shear wave absolute vibro-elastography with an xmatrix array-a healthy volunteer study. in 2018 IEEE International Ultrasonics Symposium (IUS). 2018. IEEE.
33. Aleef, T.A., et al., Quasi-real time multi-frequency 3d shear wave absolute vibro-elastography (s-wave) system for prostate. arXiv preprint arXiv:2205.04038, 2022.
34. Shao, Y., et al., Breast cancer detection using multimodal time series features from ultrasound shear wave absolute vibro-elastography. IEEE Journal of Biomedical and Health Informatics, 2021. 26(2): p. 704-714.
35. Hong, Z., J. Zhang, and B.W. Drinkwater, Observation of orbital angular momentum transfer from Bessel-shaped acoustic vortices to diphasic liquid-microparticle mixtures. Physical review letters, 2015. 114(21): p. 214301.
36. Lo, W.C., et al., Tornado-inspired acoustic vortex tweezer for trapping and manipulating microbubbles. Proceedings of the National Academy of Sciences of the United States of America, 2021. 118(4).
37. Kang, S.T. and C.K. Yeh, Potential-Well Model in Acoustic Tweezers. Ieee Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2010. 57(6): p. 1451-1459.
38. Lo, W.-C., et al., 3-D ultrafast ultrasound imaging of microbubbles trapped using an acoustic vortex. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2021. 68(12): p. 3507-3514.
39. Gosse, C. and V. Croquette, Magnetic tweezers: Micromanipulation and force measurement at the molecular level. Biophysical Journal, 2002. 82(6): p. 3314-3329.
40. Guo, S.F., et al., Reduced clot debris size using standing waves formed via high intensity focused ultrasound. Applied Physics Letters, 2017. 111(12).
41. Ghanem, M.A., et al., Noninvasive acoustic manipulation of objects in a living body. Proceedings of the National Academy of Sciences of the United States of America, 2020. 117(29): p. 16848-16855.
42. Wu, P.Y., et al., Focused Acoustic Vortex-Regulated Composite Nanodroplets Combined with Checkpoint Blockade for High-Performance Tumor Synergistic Therapy. Acs Applied Materials & Interfaces, 2022. 14(27): p. 30466-30479.
43. Fabrice Prieur, S.C., Simulation of shear wave elastography imaging using the toolbox “k-Wave”. Acoustical Society of America, 2016.
44. Prieur, F. and O.A. Sapozhnikov, Modeling of the acoustic radiation force in elastography. The Journal of the Acoustical Society of America, 2017. 142(2): p. 947-961.
45. Treeby, B.E., et al., Modeling nonlinear ultrasound propagation in heterogeneous media with power law absorption using ak-space pseudospectral method. The Journal of the Acoustical Society of America, 2012. 131(6): p. 4324-4336.
46. Gennisson, J.L. and G. Cloutier, Sol-gel transition in agar-gelatin mixtures studied with transient elastography. Ieee Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2006. 53(4): p. 716-723.
47. Pinton, G.F., J.J. Dahl, and G.E. Trahey, Rapid tracking of small displacements with ultrasound. IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 2006. 53(6): p. 1103-1117.
48. Yeh, C.-L., et al., Shear-wave elasticity imaging of a liver fibrosis mouse model using high-frequency ultrasound. IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 2015. 62(7): p. 1295-1307.
49. Kasai, C., et al., Real-Time Two-Dimensional Blood Flow Imaging Using an Autocorrelation Technique. IEEE Transactions on Sonics and Ultrasonics, 1985. 32(3): p. 458-464.
50. Deffieux, T., et al., On the Effects of Reflected Waves in Transient Shear Wave Elastography. Ieee Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2011. 58(10): p. 2032-2035.
51. Song, P., et al., Comb-push ultrasound shear elastography (CUSE): a novel method for two-dimensional shear elasticity imaging of soft tissues. IEEE transactions on medical imaging, 2012. 31(9): p. 1821-1832.
52. Feng, F., et al., Shear Wave Elasticity Imaging Using Nondiffractive Bessel Apodized Acoustic Radiation Force. Ieee Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2021. 68(12): p. 3528-3539.
53. Ouared, A., E. Montagnon, and G. Cloutier, Generation of remote adaptive torsional shear waves with an octagonal phased array to enhance displacements and reduce variability of shear wave speeds: comparison with quasi-plane shear wavefronts. Physics in Medicine and Biology, 2015. 60(20): p. 8161-8185.
54. González-Mateo, E., N. Jiménez, and F. Camarena. Quasi-omnidirectional shear wave generation using acoustic vortices for elastography. in 2022 IEEE International Ultrasonics Symposium (IUS). 2022. IEEE.
55. Jiménez, N., J.M. Benlloch, and F. Camarena. A new elastographic technique using acoustic vortices. in 2020 IEEE International Ultrasonics Symposium (IUS). 2020. IEEE.