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[Myocardial perfusion imaging by digital subtraction angiography]
Insights
Digital subtraction angiography (DSA) methods were compared for visualizing myocardial perfusion. Time interval difference (TID) mode offered superior visualization of contrast medium passage through the coronary artery system.
Area of Science:
- Cardiology
- Medical Imaging
- Diagnostic Techniques
Background:
- Assessing regional myocardial perfusion is crucial for diagnosing coronary artery disease.
- Digital subtraction angiography (DSA) is an imaging technique used in cardiology.
- Optimizing DSA protocols can improve the visualization of coronary blood flow.
Purpose of the Study:
- To compare different digital subtraction angiography (DSA) methods for enhanced visualization of regional myocardial perfusion.
- To determine the optimal cardiac cycle phases for mask and live film acquisition in coronary angiography.
- To evaluate the effectiveness of continuous image (CI) mode versus time interval difference (TID) mode in DSA for myocardial perfusion imaging.
Main Methods:
- Comparison of DSA techniques in patients with myocardial infarction, angina pectoris, and normal coronary arteries.
- Selection of mask and live films from specific cardiac cycle phases (R wave, 100 msec before R, 200 msec before R) to minimize cardiac motion.
- Application of CI mode and TID mode DSA for visualizing contrast medium perfusion.
- Analysis of subtracted images for density and contour line display.
Main Results:
- Acquiring mask and live films 100 or 200 msec before the R wave improved image similarity due to reduced cardiac motion.
- CI mode adequately visualized overall contrast medium perfusion from artery to vein.
- TID mode visualized contrast medium passage through arteries, capillaries, and veins at specific phases.
- DSA revealed non-uniform regional myocardial perfusion in normal subjects, influenced by coronary artery anatomy.
Conclusions:
- DSA methods, particularly TID mode, can effectively visualize regional myocardial perfusion.
- Optimal selection of cardiac cycle phases is critical for accurate DSA imaging.
- Coronary artery typography influences myocardial perfusion patterns even in healthy individuals.
Abstract:
Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)