Program Information
A Novel Energy-Dependent Subtraction Method for Cardiac Imaging: Signal and Noise Analysis
C Burton*, I Cunningham , Western University, London, Ontario
Presentations
SA-B-BRD-1 (Saturday, March 5, 2016) 10:30 AM - 12:30 PM Room: Grand Ballroom D
Purpose:Cardiovascular diseases (CVD) are currently the leading cause of death worldwide and x-ray angiography is used for 80% of all cases. Digital subtraction angiography (DSA) is a technique that is widely used to enhance the visibility of vasculature obscured by overlying bone and lung fields by subtracting a mask and contrast image. However, DSA is generally unsuccessful for imaging the heart, due to the motion that occurs during the several seconds between mask and contrasted images that cause artifacts and can render a study non-diagnostic. We are proposing energy subtraction angiography (ESA) as a method of bringing the benefits of DSA to cardiac imaging without motion artifacts. This method was suggested in the 1970’s and it was concluded at the time that image quality with ESA could not compete with that of DSA, and the approach was abandoned. However, our work has shown that conclusion was based on limitations of early technology that may be no longer relevant.
Methods: We developed a theoretical model for iodine signal and noise to form a metric of comparison of iodine SNR between ESA and DSA independent of technology and validated it with experiment. Read-noise and scatter were incorporated into our theoretical model.
Results: The theoretical model showed that in principle, ESA can produce images that are as good as DSA, and experimental results were in excellent agreement. However, to achieve this, ESA places greater demands on detector performance than DSA in terms of detector quantum efficiency (DQE), read noise, and scatter.
Conclusion: With emerging detector technology and x-ray system designs, it is now possible to obtain iodine specific images for ESA with similar image quality to that of DSA. ESA has the potential to be used for background removal in cardiac imaging and other applications, where DSA cannot be used.
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