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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/62453完整後設資料紀錄
| DC 欄位 | 值 | 語言 |
|---|---|---|
| dc.contributor.advisor | 曹建和(Jen-Ho Tsao) | |
| dc.contributor.author | Chih-Hao Liu | en |
| dc.contributor.author | 劉志豪 | zh_TW |
| dc.date.accessioned | 2021-06-16T16:02:44Z | - |
| dc.date.available | 2013-07-31 | |
| dc.date.copyright | 2013-07-31 | |
| dc.date.issued | 2012 | |
| dc.date.submitted | 2013-07-04 | |
| dc.identifier.citation | [1] M. J. Cloostermans and J. M. Thijssen, “A beam corrected estimation of the frequency dependent attenuation of biological tissues from backscattered ultrasound,” Ultrason. Imag., vol. 5,no. 2, pp. 136–147, 1983.
[2] P. A. Narayana and J. Ophir, “On the frequency dependence of attenuation in normal and fatty liver,” IEEE Trans. Sonics Ultrason., vol. 30, no. 6, pp. 379–383, 1983. [3] B. Zhao, O. A. Basir, and G. S. Mittal, “Estimation of ultrasound attenuation and dispersion using short time Fourier transform,” [4] Ping He,”acoustic parameter estimation based on attenuation and dispersion measurements” IEEE/EMBS,1998 [5] Roman kus,member,IEEE,” Estimating Acoustic Attenuation from Reflected Ultrasound Signals: Comparison of Spectral-Shift and Spectral-Difference Approaches”vol. Assp-32,No,1,February 1984 [6] Keith A.Wear,Senior Member,IEEE “The Effects of Frequency-Dependent Attenuation and Dispersion on Sound Speed Measurements: Applications in Human Trabecular Bone” VOL. 47, NO. 1, JANUARY 2000 [7] Hyungsuk Kim, James A. Zagzebski, and Tomy Varghese'Estimation of Ultrasound Attenuation from Broadband Echo-Signals Using Bandpass Filtering'VOL.55,No.5, May2008 [8] Greg Wojcik, John Mould, SeviAg yter*, Laura Carcione'A Study of Second Harmonic Generation by Focused Medical Transducer Pulses' [9] “Greg Wojcik, John Mould, SeviAg yter*, Laura Carcione”A Study of Second Harmonic Generation by Focused Medical Transducer Pulses [10] James D. Thomas, MD, FACC, and David N. Rubin, MD, Cleveland, Ohio”Tissue Harmonic Imaging: Why Does It Work?” [11] Roman Kuc,Member,IEEE “Bounds on Estimating the Acoustic Attenuation of Small Tissue Regions from Reflected Ultrasound”1985 [12] Mark F. Hamilton and David T. Blackstock “nonlinear acoustics” 1998 [13] Francois Varray, olivier Basset, Piero Tortoli, and christian cachard” Extensions of Nonlinear B/A Parameter Imaging Methods for Echo Mode” vol. 58, no. 6, June 2011 [14] G. Wojcik, B. Fomberg, R.Waag, ” Pseudospectral methods for large-scale bioacoustic models”1997,IEEE [15] G Wojcik,” Nonlinear modeling of therapeutic ultrasound”,1995,IEEE [16] T.D. Mast, L.M, Hinkelman, “Simulation of ultrasonic pulse propagation through the abdominal wall” J. Acousr. Soc. Am., 102(2), 1177-1 190, 1997. [17] B.Fomberg,”A Practical Guide to Pseudosuectral Methods” Cambridge University press 1996 [18] J.-P. Berenger”A perfectly matched layer for the absorption of electromagnetic waves”,Computational Physics, 114, 185-200, 1994. [19] Xiaojuen Yuan, “Formulation and Validation of Berenger's PML. Absorbing Boundary for the FDTD. Simulation of Acoustic Scattering”.IEEE,1997 | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/62453 | - |
| dc.description.abstract | 超音波影像解析度深受發射訊號的頻寬影響。欲得到高解析度影像則需要較高頻寬，目前常用來提升影像解析度是組織二倍頻諧波成相技術。然而，發射訊號頻寬與發射訊號週期數成反比，二倍頻產生能力與發射訊號週期數成正比。為了得到更高解析度得影像反而降低回波訊號的能量。因此，先前有人提出了合頻技術，運用窄頻寬利於二倍頻產生的特性，提升回波訊號的能量且透過提升合頻個數達到與脈衝反向技術相同的解析度。因此合頻技術可以擁有高對比度與解析度特性。然而合頻與寬頻脈衝反向技術同樣面臨組織衰減，散射子問題。因此本篇研究利用合頻的窄頻特性，提出衰減與散射子補償辦法使合頻的解析度與對比度獲得更好的提升。 | zh_TW |
| dc.description.abstract | The resolution of Ultrasound images is limited by the bandwidth of emitted signal; wider bandwidth is required for images with better resolution. Nowadays, tissue harmonic imaging utilized its broader bandwidth to achieve high-resolution images. However, the number of pulse cycles is reciprocal to the bandwidth of emitted signal but proportional to the production of Tissue Harmonic Signal. In order to break the trade-off between pulse cycles and image resolution, Synthetic Spectrum Imaging (SSI) was presented previously, the principle of which is based on the advantage that narrow band is beneficial to the production of Tissue Harmonic Signal. Under this advantage, the power of THS can be improved and the resolution can be raised to the same level with Pulse Inversion (PI) by increasing the number of synthetic bands. Thus, Synthetic Spectrum technique is capable to acquire high resolution and SNR images. Nevertheless, Synthetic Spectrum imaging has its challenge comes from the absorption effect of tissues, the main reason to reduce the benefits of SSI. Consequently, we presented a correction method to compensate the absorption effect of tissues for maintaining the high SNR and resolution benefits from SSI.
Keywords: Synthetic Spectrum Imaging; tissue harmonic imaging; attenuation correction image; attenuation measurement; Pulse inversion. | en |
| dc.description.provenance | Made available in DSpace on 2021-06-16T16:02:44Z (GMT). No. of bitstreams: 1 ntu-101-R99945048-1.pdf: 3496702 bytes, checksum: 0de117978b5303f68bc2e30e4c8c39ff (MD5) Previous issue date: 2012 | en |
| dc.description.tableofcontents | 口試委員會審定書 #
誌謝 i 中文摘要 ii CONTENTS iii LIST OF FIGURES v LIST OF TABLES ix Chapter 1 1 1.1 研究動機 1 1.2 論文架構 2 Chapter 2 模擬方法介紹 3 2.1 Pseudospectral Wave Solver 3 2.2 Simulation of ultrasound RF signal as affected by tissue property 6 2.2.1 Acoustic equation with relaxation attenuation and absorbing boundary condition 6 2.2.2 Nonlinearity 8 2.3 Simulation procedure 10 Chapter 3 衰減估測模擬 12 3.1 估測方法選擇 12 3.2 Log Spectral difference method 14 3.3 衰減估測問題 15 3.3.1 頻寬 15 3.3.2 B/A 非線性參數 18 3.3.3 Scattering effect 25 3.3.4 提出估測方法 29 Chapter 4 合頻補償 33 4.1 合頻原理介紹 33 4.2 合頻問題 36 4.2.1 中心頻差距對相位影響 36 4.2.2 發射訊號頻寬選擇 41 4.2.3 衰減量對合頻影響 42 4.2.4 散射子對合頻影響 46 4.3 提出正確補償方法 54 Chapter 5 效能 63 5.1 效能估測方式 63 5.2 散射子對合頻效能影響 69 Chapter 6 結論 72 參考文獻 73 | |
| dc.language.iso | zh-TW | |
| dc.title | 諧波成像衰減補償 | zh_TW |
| dc.title | Synthetic Spectrum Harmonic correction
Imaging | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 101-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 羅孟宗(Men-Tzung Lo),林文澧(Win-Li Lin) | |
| dc.subject.keyword | 組織諧波,超音波成像,諧波合頻,衰減補償, | zh_TW |
| dc.subject.keyword | Synthetic Spectrum Imaging,tissue harmonic imaging,attenuation correction image,attenuation measurement,Pulse inversion, | en |
| dc.relation.page | 73 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2013-07-04 | |
| dc.contributor.author-college | 電機資訊學院 | zh_TW |
| dc.contributor.author-dept | 生醫電子與資訊學研究所 | zh_TW |
| 顯示於系所單位： | 生醫電子與資訊學研究所 | |
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