Cinevideodensitometric quantification of relative coronary arterial stenosis: application to evaluating candidates for percutaneous transluminal coronary angioplasty
Related Experiment Videos
A Azuma1, K Furukawa, H Katsume
1Second Department of Internal Medicine, Kyoto Prefectural University of Medicine.
Insights
Cinevideodensitometry offers an objective method for measuring coronary artery stenosis after percutaneous transluminal coronary angioplasty (PTCA). This technique accurately quantifies arterial changes, outperforming edge detection for asymmetrical lesions.
Area of Science:
- Cardiology
- Medical Imaging
- Interventional Cardiology
Background:
- Visual interpretation of angiograms has limitations.
- Percutaneous transluminal coronary angioplasty (PTCA) requires accurate assessment of coronary artery stenosis.
- Existing methods like edge detection may struggle with asymmetrical lesions.
Purpose of the Study:
- To evaluate cinevideodensitometry as an alternative to visual interpretation and edge detection for assessing coronary arteries dilated by PTCA.
- To compare the accuracy and reproducibility of cinevideodensitometry and edge detection methods.
Main Methods:
- Coronary arteriograms were analyzed using cinevideodensitometry and edge detection.
- Phantom models with symmetrical and asymmetrical stenoses were used for system testing.
- Analysis was performed on cineangiograms from 58 patients with ischemic heart disease, including 28 who underwent PTCA.
Main Results:
- Cinevideodensitometry showed a linear correlation between phantom area and summed gray levels.
- Both methods were accurate for symmetrical stenosis, but edge detection varied with projection for asymmetrical stenosis.
- Discrepancies between methods were observed post-PTCA in cases of asymmetrical luminal changes.
Conclusions:
- Cinevideodensitometry provides objective, accurate, and reproducible measurements of coronary arterial stenosis.
- This method can quantify eccentric lesions in a single projection without tracing arterial borders.
- Cinevideodensitometry is a valuable tool for assessing PTCA outcomes.
Abstract:
As an alternative to visual interpretations of subjects' angiograms, coronary arteries dilated by percutaneous transluminal coronary angioplasty (PTCA) were evaluated using cinevideodensitometry, and the results were compared with those obtained by the edge detection method. Coronary arteriograms were obtained in various projections and suitable frames were selected for analysis. The frames were transformed to digitized images (512 X 512 X 8 bits) with an image analyzer (MIPRON 1), and cinevideodensitometric and edge detection analyses were performed. Phantom models of various shapes were opacified with contrast medium and were used to test our system. The cineangiograms of 58 patients with ischemic heart disease, 28 of whom had underwent PTCA, were analyzed. A highly linear correlation was observed between the cross-sectional areas of the phantoms and the summed gray levels measured using cinevideodensitometry. Percent area stenosis evaluated by the two methods was accurate and reproducible in measuring the symmetrical stenosis models. However, for the model of asymmetrical stenosis, the measurement by the edge detection method differed according to various projections. Similar results were obtained measuring asymmetrical stenosis in the right coronary artery in vivo in various projections. Based on these experimental results, coronary stenoses dilated by PTCA were evaluated. Prior to PTCA, coronary arterial stenosis measured using the two methods closely approximated each other. However, following PTCA, there were discrepancies between the measurements by the two methods in six cases. This can be accounted for by asymmetrical changes in a luminal cross-section, which cannot be accurately assessed using the edge detection method in single plane projection. In conclusion, cinevideodensitometric measurements of relative coronary arterial stenosis were objective, accurate, and reproducible. According to cinevideodensitometric analysis, eccentric lesions can be measured using a single projection, and tracing arterial borders is unnecessary. It is a useful means in measuring quantitatively the degree of dilatation of coronary arterial stenosis accomplished by PTCA.