資料分享式螺旋槳磁振造影基於螺旋槳取樣特性，於每張槳葉重複取樣k空間中央資料，提供影像整體對比，藉由重建槳葉縮短單張影像所需取樣時間以提高時空解析度。於重建高空間解析度影像時，k空間中央只由單一標的槳葉提供，使重建影像呈現標的槳葉時間解析度，透過適當的使用時序上連續的不同旋轉角度槳葉提供其餘所需高頻資訊。

本研究針對View-sharing PROPELLER使用流體仿體模擬對比劑動態顯影，驗證其可行性及正確性。並且實際應用於健康受試者無顯影劑心臟造影，搭配心電圖監測，在閉氣及自由呼吸的條件下，獲得不錯影像結果，只有因FOV不足造成少量影像假影。

Based on the acquisition trajectory, PROPELLER MRI repeatedly sampled the center k-space in every blade, which was used to provide most of the energy of an image. The purpose of view sharing PROPELLER is to improve the spatio-temporal resolution of dynamic imaging by reducing the acquisition time of single frame to that of single blade. With the center k-space provided by only one blade, which is called the target blade, the high spatial-frequency components were appropriately contributed by a set of neighboring blades with different rotation angles, leading to the high spatial resolution after reconstruction.

In this study, a flow phantom experiment with the injection of T1-shortening Gd-DTPA solution was performed to exam the feasibility and accuracy of view-sharing PROPELLER. Furthermore, cardiac imaging of healthy volunteer obtained by the proposed technique was also done with ECG gating to test the image quality without any injection of contrast agent. The in-vivo experiment was done with and without breath holding. In addition to slight aliasing artifact due to insufficient FOV, no other artifact was observed.

論文審定書 i
誌謝 ii
中文摘要 iii
英文摘要 iv
目錄 v
圖目錄 vii
表目錄 ix
第一章 簡介 1
第一節 背景 1
第二節 研究動機 4
第二章 原理 6
第一節 資料分享式螺旋槳磁振造影(View-Sharing PROPELLER) 6
第二節 POBS(pixel-based optimal blade selection)演算法 7
第三章 實驗設計 10
第一節 仿體實驗 10
第二節 人體實驗 17
第四章 實驗結果 20
第一節 仿體實驗 20
第二節 人體實驗 30
第五章 討論 37
第一節 仿體實驗 37
第二節 人體實驗 55
第六章 結論 59
參考文獻 61

[1] R. A. Jones, et al., "K-space substitution: a novel dynamic imaging technique," Magn Reson Med, vol. 29, pp. 830-4, Jun 1993.
[2] J. J. van Vaals, et al., ""Keyhole" method for accelerating imaging of contrast agent uptake," J Magn Reson Imaging, vol. 3, pp. 671-5, Jul-Aug 1993.
[3] M. Doyle, et al., "Block regional interpolation scheme for k-space (BRISK): a rapid cardiac imaging technique," Magn Reson Med, vol. 33, pp. 163-70, Feb 1995.
[4] F. R. Korosec, et al., "Time-resolved contrast-enhanced 3D MR angiography," Magn Reson Med, vol. 36, pp. 345-51, Sep 1996.
[5] K. K. Vigen, et al., "Undersampled projection-reconstruction imaging for time-resolved contrast-enhanced imaging," Magn Reson Med, vol. 43, pp. 170-6, Feb 2000.
[6] A. V. Barger, et al., "Time-resolved contrast-enhanced imaging with isotropic resolution and broad coverage using an undersampled 3D projection trajectory," Magn Reson Med, vol. 48, pp. 297-305, Aug 2002.
[7] C. A. Mistretta, et al., "Highly constrained backprojection for time-resolved MRI," Magn Reson Med, vol. 55, pp. 30-40, Jan 2006.
[8] J. G. Pipe, "Motion correction with PROPELLER MRI: application to head motion and free-breathing cardiac imaging," Magn Reson Med, vol. 42, pp. 963-9, Nov 1999.
[9] F. N. Wang, et al., "PROPELLER EPI: an MRI technique suitable for diffusion tensor imaging at high field strength with reduced geometric distortions," Magn Reson Med, vol. 54, pp. 1232-40, Nov 2005.
[10] T. C. Chuang, et al., "Data-sharing PROPELLER imaging for increased temporal resolution retaining spatial resolution and image contrast," presented at the Proceeding of 14th Annual Meeting of International Society for Magnetic Resonance in Medicine, Seattle, Washington, U.S., 2006.
[11] T. C. Chuang, et al., "View-sharing PROPELLER with pixel-based optimal blade selection (POBS) for dynamic-enhanced MRI," presented at the Proceeding of 16th Annual Meeting of Internatioal Society for Magnetic Rsonance in Medicine, Toronto, Canada, 2008.
[12] T. C. Chuang, "PROPELLER keeps spinning : advanced technique development and applications of PROPELLER MRI " PhD, Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, 2007.
[13] M. A. Bernstein, et al., Handbook of MRI Pulse Sequences: Elsevier Academic Press, 2004.
[14] PhysioBank. MIT/BIH arrhythmia database [Online].