Wagner S, Auffermann W, Buser P, Semelka R C, Higgins C B
Department of Radiology, University of California School of Medicine, San Francisco 94143.
Am J Card Imaging. 1991 Jun;5(2):87-97.
Cine magnetic resonance imaging (MRI) is a three-dimensional imaging technique with sufficient temporal resolution to provide quantitation of left ventricular (LV) dimensions and function. It can be used to describe the three-dimensional geometrical and functional characteristics of various cardiac disease states. Accordingly, the purpose of the study was to noninvasively characterize LV function with cine MRI using LV mass, systolic wall stress, ejection fraction, and fractional wall thickening, and to compare these functional determinants among three major cardiac disease states. Patients were selected from echocardiographic criteria and specific history of disease and divided into the following groups: compensated moderate to severe aortic regurgitation; compensated LV hypertrophy caused by systemic hypertension; and dilated congestive cardiomyopathy. Normal subjects without evidence of heart disease were studied for comparison. Cine MRI was performed at 1.5 Tesla in the short-axis plane. Wall stress was calculated from MRI, along with blood pressure recordings and carotid pulse tracings, according to the Laplacian expression. The end-diastolic volume to LV mass ratio distinguished between concentric and eccentric LV hypertrophy. Peak-systolic wall stress was increased in volume overload lesions and myocardial disease and significantly different (P less than .01) compared with pressure overload lesions and normal subjects. Ejection fraction was significantly decreased (P less than .01) in myocardial disease compared with volume and pressure overload lesions and normal subjects. Among these disease states, LV mass was not different but was significantly higher in all (P less than .01) compared with normal subjects. Fractional wall thickening was increased in pressure overload lesions. Thus, the increase in LV mass in volume overload lesions and primary myocardial disease is not adequate to prevent an increase in wall stress, whereas LV mass increased sufficiently in pressure overload lesions to normalize systolic wall stress. Cine MRI can be used to noninvasively describe the three-dimensional geometry and functional state of the heart in various pathological conditions and might be used to monitor therapeutic effects.
电影磁共振成像（MRI）是一种三维成像技术，具有足够的时间分辨率，可用于定量分析左心室（LV）的大小和功能。它可用于描述各种心脏疾病状态的三维几何和功能特征。因此，本研究的目的是通过电影MRI，利用左心室质量、收缩期壁应力、射血分数和壁增厚分数对左心室功能进行无创性特征描述，并比较这三种主要心脏疾病状态下的这些功能决定因素。根据超声心动图标准和特定疾病史选择患者，并将其分为以下几组：代偿性中度至重度主动脉瓣反流；由系统性高血压引起的代偿性左心室肥厚；以及扩张型充血性心肌病。选取无心脏病证据的正常受试者作为对照进行研究。在1.5特斯拉磁场下于短轴平面进行电影MRI检查。根据拉普拉斯表达式，从MRI计算壁应力，并记录血压和颈动脉搏动曲线。舒张末期容积与左心室质量之比可区分向心性和离心性左心室肥厚。容积超负荷病变和心肌疾病中，收缩期峰值壁应力增加，与压力超负荷病变和正常受试者相比有显著差异（P<0.01）。与容积和压力超负荷病变及正常受试者相比，心肌疾病中的射血分数显著降低（P<0.01）。在这些疾病状态中，左心室质量无差异，但与正常受试者相比，所有疾病状态下均显著更高（P<0.01）。压力超负荷病变中壁增厚分数增加。因此，容积超负荷病变和原发性心肌疾病中左心室质量的增加不足以防止壁应力增加，而压力超负荷病变中左心室质量充分增加以使收缩期壁应力正常化。电影MRI可用于无创性描述各种病理状态下心脏的三维几何形状和功能状态，并可能用于监测治疗效果。
