資料共享式螺旋槳磁振造影於擴散權重影像之應用：模擬研究

Abstract

多 b 值數據共享式螺旋槳擴散權重磁振影像的可行性將在此論文中被探討。此技術的提出主要將針對螺旋槳式磁振造影取像過程過久之問題進行修正。透過收取不同權重值的槳葉擴散影像並嘗試重建之，影像的取得速度將會依據共享的槳葉數量進行提升。在初步的嘗試中，影像可被成功的重建成高解析度影像，然而k 空間訊號特性將使得這樣的重建方式會於影像上出現假影。假影的詳細成因和降低方法將在本文中被提出。透過此方法，不同擴散能力的組織共存於同一像素內所造成之雙指數訊號衰減將有機會被正確的呈現。

The feasibility of Data Sharing PROPELLER MR imaging with multiple b-values is first proposed and evaluated in this thesis. This technique aims to shorten the amount of time when acquiring PROPELLER diffusion weighted images. Preliminary result of this thesis demonstrated that it is possible to combine each under-sampled rotating blades encoded with respect to different b-values together to create high resolution images. The combination process is accompanied with some unwanted artifacts due to data discrepancies between central and outer k-space. However, the reason and the possible strategies to reduce its effects are also proposed. The proposed methodology is able to quantitatively measure the signal behavior of bi-exponential decays.