A contrast enhancement filter for improving stent visibility in interventional X-ray fluoroscopy: an initial study.

Low exposure X-ray fluoroscopy is widely used to guide some complicate interventional procedures. Given its inherent high noise, improving the visibility of interventional devices such as stents will greatly benefit the procedures. In this study, a contrast enhancement filter has been proposed to improve stent visibility. It is designed to selectively improve the contrast of stent contour segments without dramatically accentuating quantum and clinical background noises. To achieve this, convolution directional filter banks were applied to detect the edges and orientations of stent. Next, symmetry measures were used to extract symmetrical portions of the stent image. Those information were combined to generate a partial stent contour map. The contour map was then scaled and added back to the original image to get the stent in the image contrast enhanced. It is shown that this stent enhancement filter effectively improves stent visibility in the interventional X-ray fluoroscopy.