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dc.contributor.advisorJan-Ray Liaoen_US
dc.contributor.authorDai, Chia-Tanen_US
dc.description.abstract數年來,腦部磁振造影科技的研發日新月異,由於超高速及高解析度動態造影的發展,開啟了偵測腦中血流的新機。有關腦部功能性磁振影像及其相關之腦部擴散/灌流影像(diffusion/perfusion imaging)之技術亦日漸成熟。 在1.5T磁場強度之全身測量系統,以超高速及高解析度動態影像波序(EPI),患者在經靜脈快速注射對比劑(Gd+-DTPA, 0.2mmol/kg, 3cc/sec)後,以其在局部組織中 T2* 效應,獲取微血管灌流影像。整個灌流影像檢查動態過程共取9個切面,包括四十五個相位(Phase),以取得不同相位時影像中訊號的變化相,全部共405張灌流影像。將所得之灌流影像經由電腦處理得到有趣部位 (ROI, region of interest)的訊號強度對時間曲線;根據公式,T2*訊號強度的改變和顯影劑及血流量均呈現線性的關係。由此訊號強度對時間曲線獲得相對腦血流容積(rCBV, relative cerebral blood volume),相對腦血流量(rCBF, relative cerebral blood flow),和腦組織平均血流穿透時間(tMTT, tissue mean transit time),再由以上分析的資料產生不同的灌流組像(perfusion mapping)。 在此研究中,我們由GE的磁振造影檢查儀得到的影像原始資料經由轉換過程傳送至個人電腦,建立影像資料庫,並經由自動偵測讀取,濾波和遮罩等影像處理技巧作處理,再依數學計算公式的應用取得灌流影像的rCBV Mapping。zh_TW
dc.description.abstractIn recent years, the research and development of Magnetic Resonance Imaging (MRI) has proceeded very rapidly. The development of ultra-fast and high-resolution imaging methods has opened up brand new opportunities for detecting the status of blood flow in the brain. The technology of functional MRI and its related brain diffusion/perfusion imaging has become more and more mature recently. In a whole body system of 1.5T magnet, we use a high-speed and high-resolution dynamic imaging sequence, to acquire the perfusion images of capillaries after intravenous administration of contrast media (Gd+-DTPA, 0.2mmol/kg, 3cc/sec). The entire imaging process took nine slices, including 45 phases for each slice, in order to obtain the temporal change of the signals . Through image processing, the curve of signal level versus time for the Region of Interest (ROI) in perfusion images was then generated. The relationship between the T2* signal changes and the volume of contrast medium (i.e., blood volume)is linear. From the curve of signals versus time, the Relative Cerebral Blood Volume (rCBV), Relative Cerebral Blood Flow (rCBF), and Tissue Mean Transit Time (tMTT) were obtained. Then, different perfusion mappings were generated. In this thesis, we sent the images obtained from the GE-MRI scanner to a personal computer. After creating the imaging database, the data are processed to obtain the rCBV mapping through auto detection and a number of image-processing techniques, such as filtering and masking.en_US
dc.description.tableofcontents第一章、研究背景 第二章、磁振造影醫學診斷簡介與臨床影像 2.1 核磁共振的發現與優點 2.2 擴散與灌流磁振造影的應用與發展 2.2.1 擴散磁振造影 2.2.2 灌流磁振造影 第三章、灌流分析 3.1 腦部灌流影像分析現況概要 3.2 腦部血液動力學 3.2.1 前言 3.2.2 從靜脈端的觀察 3.2.3 從組織內部的觀察 3.3 對比劑在腦部病變影像診斷的重要性 3.4 濃度時間曲線 3.5 腦血容積(CBV)的量測 第四章、研究過程及步驟 4.1 實驗設備 4.2 實驗流程及步驟 4.2.1 取得影像資訊 4.2.2 DICOM 格式轉換 4.3 影像處理 4.3.1 空間濾波 4.3.2 遮罩(Mask) 4.3.3 建立腦血容積 4.3.4 彩色轉換處理 4.4 程式範例 4.4.1 建立影像資料庫 4.4.2自動偵測head size 4.4.3讀取切面影像 4.4.4 空間濾波 4.4.5 遮罩(Mask) 4.4.6 組像(Mapping) 第五章、研究結果分析與比較 5.1 前言 5.2 臨床應用 5.2.1 病例A 5.2.2 病例B 第六章、討論與結論 6.1 灌流分析問題 6.2 影像處理問題 6.3 實驗結果比較 6.4 未來展望與結論 參考文獻zh_TW
dc.subjectrelative cerebral blood volumeen_US
dc.subjectrelative cerebral blood flowen_US
dc.subjecttissue mean transit timeen_US
dc.titlePost-processing of Brain Functional MR Imagingen_US
dc.typeThesis and Dissertationzh_TW
item.openairetypeThesis and Dissertation-
item.fulltextno fulltext-
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