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研究生： 王基崇
Chi-chung Wang
論文名稱： 螺旋槳型編碼之自我運動追踨術：心肌動態磁振造影之應用
Self-gated PROPELLER cine cardiac imaging: Simultaneously tracking the cardiac pulsation and the respiratory motion
指導教授： 黃騰毅
Teng-yi Huang
口試委員: 林益如
none
劉益瑞
none
柯正雯
none
學位類別： 碩士
Master
系所名稱： 電資學院 - 電機工程系
Department of Electrical Engineering
論文出版年： 2007
畢業學年度： 95
語文別： 英文
論文頁數： 49
中文關鍵詞： 心電圖觸發 、閉氣 、螺旋槳型編碼法 、運動同步
外文關鍵詞： EKG trigger, breath-hold, PROPELLER encoding, motion synchronization
相關次數： 點閱：154  下載：4 
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  •  上一筆

    • 在心臟磁振造影中為了避免運動假影對成像造成影響，一般的輔助方式是同時採用閉氣以及心電圖觸發。然而在實際臨床應用上，有些病人因為疾病或者年老的關係而無法自主性的閉氣，心電圖觸發系統也常常因為磁振造影儀的磁場影響而必須重複設定。這些都是造成心臟磁振造影比其他身體部位的磁振造影要困難的原因。為了解決這些困難點，在本論文裡提出了一項不需要使用閉氣以及心電圖觸發技術輔助的心臟磁振造影技術。此心臟成像技術是基於螺旋槳型編碼法以及self-gating技術，並適用於大部分以傅立葉轉換為基礎的影像擷取方式。藉由此技術，可以從磁振造影訊號裡擷取出心臟與呼吸運動的同步資料，並將之應用於重建高解析度的心臟動態影像。

    In order to reduce motion-related artifacts, breath-holding and EKG trigger is generally required for cardiac MRI. However, in the clinical practice, some patients can not perform voluntary breath-hold and the EKG trigger system sometimes fails due to the interference of magnetic field and gradient system. To solve this problem, a new cardiac imaging technique with the need for EKG trigger and breath-hold, is proposed. This new cardiac imaging technique, which is designed for cine cardiac imaging, is based on self-gating technique with PROPELLER encoding. By this technique, the patient can freely breathe during the scan of cine cardiac imaging. Moreover, the cardiac motion synchronization data can be calculated directly from MRI signal and can apply to retrospective cine cardiac image reconstruction. Therefore, the EKG trigger is not necessary during the scan. This technique is suitable for most FFT-based acquisitions, such as gradient-echo sequences or EPI. Experimental results on a 3.0 Tesla MR system showed that this method can be applied to reconstruct cine cardiac images without prominent artifacts.

    Contents: I Abstract III 中文摘要 IV Chapter 1. Introduction 1 1.1 Basic MRI 1 1.2 Cardiac MR (CMR) Image with cardiac triggering 2 1.3 The Self-gating method 5 Chapter 2. Theory 7 2.1 Periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) 7 2.2 PROPELLER image reconstruction 9 2.2.1 Data-Driven vs. Grid-Driven 9 2.2.2 Mathematical Model of Re-gridding Procedures 12 2.2.3 Convolution Kernels 14 2.2.3 Spin-density Compensation , Deapodization, and K-space Over-sampling 17 Chapter3. Materials and Methods 22 3.1 Self-gating Data Acquisition 22 3.2 Human experiments 24 3.3 Self-gating Post-processing 24 3.3.1 Step 1: Extracting the trace of cardiac motion. 27 3.3.2 Step 2: Rearrange PROPELLER blades according to cardiac trace 27 3.3.3 Step 3: Extracts the respiratory trace 29 Chapter 4. Result 32 Chapter 5 Discussion and conclusion 43 5.1 Discussion 43 5.1.1 Image reconstruction for PROPELLER encoding 43 5.1.2 Self-gating method 44 5.2 Conclusion 44 Reference: 46 Appendix 48 Correlation analysis 48

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