X-ray densitometry systematically overestimated electromagnetically measured coronary flow by about 20%, but successfully revealed typical pulsatile flow patterns in 34 patients.
Observational (n=34)
Does x-ray densitometry accurately measure systolic and diastolic flow rates in the coronary artery system compared to electromagnetic flow measurements?
X-ray densitometry systematically overestimates coronary flow by about 20% compared to electromagnetic measurements, but provides typical pulsatile flow patterns and consistent flow velocities that may serve as an index for stenosis effects.
Effect estimate: Overestimated by about 20%
The reliability of a modified videodensitometric and photodensitometric sampling technique for measuring phasic flow rates in the coronary artery system was examined. Electromagnetic flow measurements were performed in a circulatory model with continuous and pulsatile flow and intraoperatively in aortocoronary bypass grafts; cineangiograms were made simultaneously. Based on the front velocities of injected boluses of contrast medium, the densitometric measurement overestimated the electromagnetically measured flow systematically by about 20%. Systolic and diastolic flow rates in aortocoronary bypass grafts and coronary arteries determined from biplane cineangiograms in 34 patients generally revealed the typical pulsatile flow pattern familiar from electromagnetic and ultrasonic flow measurements. Flow velocities in unstenosed coronary arteries were nearly identical before and after branchings of the vessels, whereas the corresponding flow rates were higher in proximal than in distal segments. The identical flow velocities in different branches of the same vessel and the low variability of this parameter in different patients may be a suitable index of the effect of stenoses on coronary arterial blood flow.
Spiller et al. (Mon,) conducted a observational in Coronary artery disease (patients with aortocoronary bypass grafts) (n=34). X-ray densitometry (videodensitometric and photodensitometric sampling) vs. Electromagnetic flow measurements was evaluated on Phasic flow rates in the coronary artery system (Overestimated by about 20%). X-ray densitometry systematically overestimated electromagnetically measured coronary flow by about 20%, but successfully revealed typical pulsatile flow patterns in 34 patients.