- 期刊
減少1.5T攝護腺磁振造影擴散加權影像偽影干擾之方法
Reduction of Ghost Artifacts in Diffusion-weighted Prostate 1.5 Tesla MRI
摘要
擴散加權磁振造影是診斷攝護腺癌的利器，因其高磁場敏感性的特性及採用快速編碼方式，常產生影像扭曲失真（distortion）及偽影﹙ghosting artifacts﹚等干擾假影，攝護腺擴散加權磁振造影常見高亮度偽影干擾，偽影發生在攝護腺及腹腔等位置會造成影像診斷的困擾。本研究使用1.5T全身磁振造影儀，選擇下腹部擴散加權檢查呈現偽影干擾之病例，在維持所有掃描條件不變下，探討使用抑訊頻帶技術對擴散加權影像高亮度偽影之影響，掃描所得兩組擴散加權影像由放射部門醫師進行判讀評分之後，進行統計分析。研究結果顯示抑訊頻帶技術有效減少擴散加權影像高亮度偽影干擾，可提高攝護腺癌影像診斷之正確性。
並列摘要
Diffusion weighted imaging (DWI) has recently been recognized as a potential clinical tool for monitoring the prostate cancer, including diagnosis accuracy and treatment efficacy. It is know that the detectablility of prostate cancer using both T2-weightd imaging (T2WI) and DWI is superior to those of using T2WI only. Single-shot Echo planar imaging (EPI) pulse sequence was used to obtain DWI images. Due to the encoding process and high magnetic field sensitivity of EPI, the image distortion and ghost are commonly presented which results in the difficulties in image interpretations. High-signal intensity aliasing artifacts mainly caused by gas in bowel loop are always appears on routine DWI images. It is difficult to predict and control because it appears randomly. The aim of this study is to evaluate the effect of spatial band saturation technique on high intensity ghost in clinical DWI images of lower abdomen DWI examinations while maintain all other scanning parameters the same using 1.5T clinical scanner. Twenty male patients were recruited into this study. Two set of acquired DWI images were interpreted and scored by radiologists. Afterwards, statistical analysis was performed. The results showed that the shining through artifacts in DWI images effectively reduced. It might be helpful for raising the accuracy of prostate cancer diagnosis and the efficacy of treatment plans.