Abstract
This paper reviews the current status of cine MR imaging of the heart with special attention to the assessmentof cardiac function. Cine MR provides tomographic sectional images with clear distinction between myocardium andflowing blood, and allows accurate volumetry of the cardiac chambers at specific points of the cardiac cycle. Fromthese volume measurements parameters for the cardiac function, such as stroke volume, ejection fraction,reguragitant fraction and shunt volume are calculated. While determination of chamber volumes can be done usingany imaging plane, regional wall motion and wall thickening are evaluated with the short axis images. These imagesare readily obtained by orienting the slice selective gradient perpendicular to the long axis of the leftventricle. Left ventricular meridional wall stress is also calculated from cine MR imges and noninvasivemeasurements of peak-and end-systolic pressure. Wall stress is an indicator of myocardial function in response toafter load and can be used for monitoring patients with myocardial disease, regurgitant valvular diseases andhypertension, and might be used to quantitaitvely assess the response of these diseases to therapy. Diseasescausing hypertrophy of the ventircles, such as valvular stenosis, systemic or pulmonary hypertension andhypertrophic cardiomyopathy, can be monitored with cine MR by measuring the myocardial mass. A signal void fromhigh velocity jets is caused by regurgitant or stenotic valvular lesion as well as flow across ventricular oratrial septal defects. Measurement of the dimension of the signal void have been correlated with the severity ofregurgitation and can be used for semi-quantitation of these lesions. Due to the inherent contrast between bloodand myocardium, high temporal resolution, and acquistition of tomographic images encompassing the entire heart,cine MR can serve as a comprehensive cardiac imaging modality that provided quantitative evaluation of anatomy andfuntion of the heart.