A New Method for the Precise and Complete Correction of Distortion on Cineangiographic Image: Its Effect on Left Ventricular Measurements

Some of the problems associated with the precise evaluation of left ventricular volumes from angiographic images are due to the magnification and distortion of the pictures obtained from X-ray equipment. Magnification errors can be evaluated easily but the distortion (due to pincushion effect) are more difficult to measure. A mathematical method is proposed for a complete point-by-point correction of errors due to magnification and X-ray distortion. This method is applicable to most currently used angiographic equipment. Since more and more angiographic images are processed with local or remote digital computers, the applicability of the proposed technique becomes realistic. Results from this study show that a 5-30% overestimation of usual geometric ventricular parameters is encountered if no correction is made for distortion. End-diastolic measurements are more affected than end-systolic ones because of the greater degree of spherical distortion at the periphery of the picture area.