[Left and right ventricular dimensions and functions measured by ECG-gated NMR cardiac imaging]

Experimental studies using static and dynamic phantoms have shown that nuclear magnetic resonance cardiac imaging (MRI) can provide accurate measurements of left ventricular wax cast volumes, wax cavity volumes and pumping volumes. Ventricular dimensions and functions of 15 normal volunteers were quantitatively studied. A multislice spin echo (SE) sequence with ECG-gating identified end-diastole and end-systole. Ventricular volumes were calculated by summing the areas of the cavities in multiple contiguous transverse sections. Stroke volume, cardiac output, and ejection fraction were consequently calculated. The right and left ventricular dimensions and functions were compared using these method. The stroke volumes of the right (71.3 +/- 13.5 ml) and left ventricles (72.5 +/- 12.1 ml) were identical. Accordingly, the cardiac outputs of the right (4.8 +/- 0.9 l/min) and left ventricles (4.9 +/- 0.8 l/min) were identical. Right ventricular end-diastolic volumes (133.6 +/- 18.6 ml) and end-systolic volumes (62.3 +/- 10.0 ml) were significantly larger than the corresponding left ventricular volumes (120.2 +/- 15.9 ml and 47.7 +/- 9.7 ml, respectively) (p less than 0.001). Right ventricular ejection fraction (53.1 +/- 5.4%) was significantly less than left ventricular ejection fraction (60.8 +/- 6.2%) (p less than 0.001). Using MRI, measurements of right and left ventricular dimensions and functions were simultaneously obtained, accurately and non-invasively.