The impact of lesion location on the accuracy of catheter calibrated vessel dimensions in routine quantitative coronary arteriography

In quantitative coronary arteriography the lumen size of a coronary segment is commonly calculated from its imaged size using the coronary catheter as a scaling device. One main source of error in this method is differential magnification. This leads to a deviation of the scaling factor from its true value and furthermore to falsified measurement of vessel dimensions. We studied the 3D-location of 468 lesions and the scaling catheters with reference to the isocenter of the X-ray gantry, their out-of-plane and the resulting measurement error by analytic angiogram quantification. Using this method calibration errors due to differential magnification for the first time have been quantified in vivo.