實時四維超音波動態心臟影像顯示及分析系統

Echocardiogram Display and Analysis for Live 4D Echocardiograph

陳巨弦(Chiu-Shian Chen)

指導教授 ： 胡威志

中原大學/工學院/醫學工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500817

摘要

為了以非侵入式之特色對心臟運動異常的局部區塊進行觀察及分析，本研究目的在於發展一套胸前心臟超音波影像軟體分析工具，直接提取影像的左心室邊緣資訊來評估左心室心室壁肌力收縮速率之表現及形態變化。系統採用四維心臟超音波影像重建出心臟實體模型，對心臟構造做初步的檢視，有助於心臟功能在系統內進行分析。影像邊緣的取得是應用動態邊緣圈選（Active Contour）快速擷取左心室心內、外膜在二維影像短軸面之邊緣資訊，並將邊緣資訊重組成立體網格模型，進而運算系統規劃之分析參數，分析參數包含：左心室容積變化曲線、質塊變化曲線、形態分析參數、室壁運動參數和心肌收縮速率。所獲得的參數經由量化處理以不同顏色表示數值大小，並利用牛眼圖（Bull’s Eye）顯示以助於分析且使用貼圖方式呈現於立體網格模型上，觀察左心室室壁在心動週期中呈現的運動狀況。
分析參數之心室容積是累計心內膜邊緣資訊之體素而得；質塊是由心內、外膜容積之差值乘上心肌組織參數（1.05 g/ml）而得。其中容積、質塊和形態變化之間的關係將用來描述左心室之功能狀態，結果顯示容積與質塊之關係為在收縮期之質塊量會逐漸增加而容積值會逐漸減少，在舒張期之質塊量會逐漸減少而容積值會逐漸增加，兩者之相關係數為0.846；室壁運動參數探討時序間之內膜半徑差，可描述室壁運動之程度；心肌之收縮速率可得知心肌在射血及充血時期收縮的快慢與變化，進而評估心肌整體之收縮與舒張運動是否具有一致性。例如：系統可以運用形態分析參數來偵測出劇烈變化或無運動之局部腔室位置等異常區域。綜觀上述之參數，本系統可對心肌異常的節段部位進行觀察及分析，未來將可應用於臨床研究和診斷上。

關鍵字

形態分析 ； 左心室 ； 超音波 ； 動態邊緣圈選 ； 室壁運動分析

並列摘要

In order to observe and analyze dysfunction location of left ventricle non-invasively, an image analysis tool using transthoracic echocardiography image has been developed to extract related data, such as wall motion, shape, time-volume curve and the change of myocardium thickness(mass). These data were extracted from the information of endocardial and epicardial boundary. The boundaries of endocardium and epicardium were traced using active contour algorithm. The traced contours were used to calculate endocardial and epicardial LV volumes by Simpson’s rule. The difference between endocardial and epicardial volumes was computed and multiplied by the specific mass of myocardial tissue(1.05 g/ml) to represent the LV mass. The time-volume, time-mass and shape relationship were used to access the status of ventricle. In result, the relationship of volume-mass has shown that the increase of mass will be leading to the decrease of volume in systole. The mass will be proportional decrease as the volume increase in diastole. The correlation of two parameters was 0.846. The degree of wall motion was represented by the traction of endocardium during each frame time. By calculating contraction velocity of myocardium, one can realize the change of myocardium in the period of ventricular ejection and ventricular filling. The data was used to estimate consistency of myocardium motion. For example, an abnormal construction pattern can be easily detected by the system. That is that the severe change and akinesia of regional chamber can be detected by shape analysis parameters. In a word, with the excellence of LV border delineating, this thesis also reported the capability of calculating LV volume, mass, parameters of LV shape analysis and wall motion analysis. In this thesis, the extracted LV functional information were using the Bull's Eye display model and texuring pattern of the three-dimension mesh model to illustrate results.

並列關鍵字

Left Ventricle ； Active Contour ； Shape Analysis ； Echocardiography ； Wall Motion Analysis

參考文獻

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