2017-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/645793摘要：瀰漫性心肌纖維化經常會造成心肌組織的細胞外間隙體積(ECV)增加，且存在於許多的心臟疾病中，因此、準確評估與定量心肌纖維化的程度，對於臨床病人的治療與追蹤相當重要。心臟磁振造影檢查，可以在一次的檢查中，同時獲得心臟血管系統的構造及功能性的影像資訊，透過ModifiedLook-Locker Inversion Recovery (MOLLI)的脈衝序列可獲得心肌組織切面的縱向鬆弛時間(T1)的圖像(T1 map)，由於T1 代表組織的物質特性，配合注射可改變T1 特性的含Gadolinium 的對比劑，便可求出心肌纖維化的ECV值。要取得心肌組織的T1 值，可透過給予一個180 度的反轉脈衝序列，然後在不同的回復時間點上進行影像的取樣(至少需要7 個取樣點)，但由於心臟在檢查的過程中會不停的跳動，因此需要藉由心電圖的監測，才能確保每次取樣的心臟影像都是在相同的心相位(cardiac phase)，同時取樣期間病人也需要閉氣，才能確保每次取樣時心臟都是維持在影像中相同的位置。由於臨床上評估病患的瀰漫性心肌纖維化，是利用圈選T1 map 中有興趣的位置(ROI)的平均T1 值去計算ECV，因此如果病人因心跳不規則或閉氣困難就會使得點像素的T1 map 的T1 值錯誤，而造成ECV 的錯誤評估。本研究主要想評估在無呼吸及心電圖監控的情況下，利用直接圈選取樣點影像上的訊號值，去回推(curve fitting)計算該ROI 的T1 值並計算其ECV，並比較其與在監控情況下從點像素的T1 map 上圈選相同的ROI 所計算的T1 值和ECV 是否具有統計上的差異。 此外、組織的T1 值會因磁場強度增加而改變，因此本研究會同時在1.5T 和3.0T 進行。<br> Abstract: Reliable assessment of increased myocardial extracellular volume (ECV), oftendue to diffuse interstitial fibrosis, is of significant clinical interest due to itsubiquitous presence in many cardiac diseases. The endomyocardial biopsy(EMB) is a diagnostic interventional procedure and remains a gold standardmode of investigation of the degree of diffuse myocardial fibrosis. However, thepathological ill appears at the endomyocardial layer might be variant through thewall of the myocardium. Cardiovascular magnetic resonance is a set of magneticresonance imaging techniques designed to assess cardiovascular morphology,ventricular function, myocardial perfusion, tissue characterization, flowquantification and coronary artery disease. Myocardial T1-mapping has beenwidely used to assess the diffuse myocardial fibrosis in various heart diseases.Modified Look-Locker inversion recovery (MOLLI) is a dedicate pulsesequence to acquire multiple images at the same cardiac phase within variousinversion times. To achieve this goal, both ECG gating and respiratory motioncontrol are needed during the imaging acquisition. Despite arrhythmia occurringin most of cardiomyopathy, respiratory motion remains a challenge to estimateT1 value for pixel-by-pixel T1-mapping of the heart. Therefore, free-breathingmyocardial T1-mapping might help for patients with difficulty in breath-hold,but its clinical feasibility on quantification of the diffuse myocardial fibrosisremains unknown. In this study, we aim to estimate the clinical feasibility offree-breathing myocardial T1-mapping to quantify the diffuse myocardialfibrosis in patients with heart failure and normal control at 1.5T and 3T.