[Simplified correction factor for the calculation of heart ventricle volume by angiography]

To measure cardiac volumes from the cineventriculographic silhouette, a calibration factor (fc) is needed to correct the X rays' distorsion and amplification. In the past, several methods have been described in order to obtain this fc, whose determination is often trouble-some, and time consuming, because of the necessity of planimetry, and calibration grid use. In this paper, we describe a method to calculate the fc: after RAO left ventriculography was obtained, a metalic sphere, whose diameter is well known, is filmed at the same incidence and distance of the left ventricle from the X ray tube and image intensifier. A good correlation was found when ventricular volumes estimated by the sphere, plannimetry of a grid, and ellipsoid axes measuring methods were compared (p less than 0.01). Methodology of the three procedures is being discussed and sphere method is recommended, because it avoids the grid use or planimetry performance and because it makes easier the fc determination.