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Quantification of fractional flow reserve based on angiographic image data.

Wong JT, Le H, Suh WM, Chalyan DA, Mehraien T, Kern MJ, Kassab GS, Molloi S - Int J Cardiovasc Imaging (2011)

Bottom Line: Pressure-wire measurements of FFR (FFR( P )) correlated linearly with angiographic volume-derived measurements of FFR (FFR( V )) according to the equation: FFR( P ) = 0.41 FFR( V ) + 0.52 (P-value < 0.001).The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively.This is the first study to provide an angiographic method to quantify FFR in swine.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, CA 92697, USA.

ABSTRACT
Coronary angiography provides excellent visualization of coronary arteries, but has limitations in assessing the clinical significance of a coronary stenosis. Fractional flow reserve (FFR) has been shown to be reliable in discerning stenoses responsible for inducible ischemia. The purpose of this study is to validate a technique for FFR quantification using angiographic image data. The study was carried out on 10 anesthetized, closed-chest swine using angioplasty balloon catheters to produce partial occlusion. Angiography based FFR was calculated from an angiographically measured ratio of coronary blood flow to arterial lumen volume. Pressure-based FFR was measured from a ratio of distal coronary pressure to aortic pressure. Pressure-wire measurements of FFR (FFR( P )) correlated linearly with angiographic volume-derived measurements of FFR (FFR( V )) according to the equation: FFR( P ) = 0.41 FFR( V ) + 0.52 (P-value < 0.001). The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively. This is the first study to provide an angiographic method to quantify FFR in swine. Angiographic FFR can potentially provide an assessment of the physiological severity of a coronary stenosis during routine diagnostic cardiac catheterization without a need to cross a stenosis with a pressure-wire.

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An example of a global region-of-interest (ROI) used for angiographically measured coronary volume flow
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Fig3: An example of a global region-of-interest (ROI) used for angiographically measured coronary volume flow

Mentions: Coronary blood flow (QS) was determined from the change in volume within one cardiac cycle. A global ROI encompassing the visible arteries, as well as the microcirculatory blush, was drawn for flow measurement (see Fig. 3). Coronary flow was then quantified using a first pass distribution analysis. The first pass distribution analysis assumes that contrast material of a known concentration enters a collection reservoir via a single arterial input and that all measurements are made prior to the contrast material leaving the selected region designated by the ROI. The change in the measured densitometric signal was converted to volume measurement using system iodine calibration. The time period of the cardiac cycle was calculated from the image acquisition rate of 30 frames/s. The ratio of the measured volume change to the time period of the cardiac cycle yields volumetric coronary blood flow [10, 11, 22].Fig. 3


Quantification of fractional flow reserve based on angiographic image data.

Wong JT, Le H, Suh WM, Chalyan DA, Mehraien T, Kern MJ, Kassab GS, Molloi S - Int J Cardiovasc Imaging (2011)

An example of a global region-of-interest (ROI) used for angiographically measured coronary volume flow
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3094747&req=5

Fig3: An example of a global region-of-interest (ROI) used for angiographically measured coronary volume flow
Mentions: Coronary blood flow (QS) was determined from the change in volume within one cardiac cycle. A global ROI encompassing the visible arteries, as well as the microcirculatory blush, was drawn for flow measurement (see Fig. 3). Coronary flow was then quantified using a first pass distribution analysis. The first pass distribution analysis assumes that contrast material of a known concentration enters a collection reservoir via a single arterial input and that all measurements are made prior to the contrast material leaving the selected region designated by the ROI. The change in the measured densitometric signal was converted to volume measurement using system iodine calibration. The time period of the cardiac cycle was calculated from the image acquisition rate of 30 frames/s. The ratio of the measured volume change to the time period of the cardiac cycle yields volumetric coronary blood flow [10, 11, 22].Fig. 3

Bottom Line: Pressure-wire measurements of FFR (FFR( P )) correlated linearly with angiographic volume-derived measurements of FFR (FFR( V )) according to the equation: FFR( P ) = 0.41 FFR( V ) + 0.52 (P-value < 0.001).The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively.This is the first study to provide an angiographic method to quantify FFR in swine.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, CA 92697, USA.

ABSTRACT
Coronary angiography provides excellent visualization of coronary arteries, but has limitations in assessing the clinical significance of a coronary stenosis. Fractional flow reserve (FFR) has been shown to be reliable in discerning stenoses responsible for inducible ischemia. The purpose of this study is to validate a technique for FFR quantification using angiographic image data. The study was carried out on 10 anesthetized, closed-chest swine using angioplasty balloon catheters to produce partial occlusion. Angiography based FFR was calculated from an angiographically measured ratio of coronary blood flow to arterial lumen volume. Pressure-based FFR was measured from a ratio of distal coronary pressure to aortic pressure. Pressure-wire measurements of FFR (FFR( P )) correlated linearly with angiographic volume-derived measurements of FFR (FFR( V )) according to the equation: FFR( P ) = 0.41 FFR( V ) + 0.52 (P-value < 0.001). The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively. This is the first study to provide an angiographic method to quantify FFR in swine. Angiographic FFR can potentially provide an assessment of the physiological severity of a coronary stenosis during routine diagnostic cardiac catheterization without a need to cross a stenosis with a pressure-wire.

Show MeSH
Related in: MedlinePlus