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Proceedings Paper

Dose reduction by moving a region of interest (ROI) beam attenuator to follow a moving object of interest
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Paper Abstract

Region-of-interest (ROI) fluoroscopy takes advantage of the fact that most neurovascular interventional activity is performed in only a small portion of an x-ray imaging field of view (FOV). The ROI beam filter is an attenuating material that reduces patient dose in the area peripheral to the object of interest. This project explores a method of moving the beam-attenuator aperture with the object of interest such that it always remains in the ROI. In this study, the ROI attenuator, which reduces the dose by 80% in the peripheral region, is mounted on a linear stage placed near the xray tube. Fluoroscopy is performed using the Microangiographic Fluoroscope (MAF) which is a high-resolution, CCD-based x-ray detector. A stainless-steel stent is selected as the object of interest, and is moved across the FOV and localized using an object-detection algorithm available in the IMAQ Vision package of LabVIEW. The ROI is moved to follow the stent motion. The pixel intensities are equalized in both FOV regions and an adaptive temporal filter dependent on the motion of the object of interest is implemented inside the ROI. With a temporal filter weight of 5% for the current image in the peripheral region, the SNR measured is 47.8. The weights inside the ROI vary between 10% and 33% with a measured SNR of 57.9 and 35.3 when the object is stationary and moving, respectively. This method allows patient dose reduction as well as maintenance of superior image quality in the ROI while tracking the object.

Paper Details

Date Published: 24 February 2012
PDF: 7 pages
Proc. SPIE 8313, Medical Imaging 2012: Physics of Medical Imaging, 831355 (24 February 2012); doi: 10.1117/12.911136
Show Author Affiliations
Ashish S. Panse, Toshiba Stroke Research Ctr., Univ. at Buffalo (United States)
S. N. Swetadri Vasan, Toshiba Stroke Research Ctr., Univ. at Buffalo (United States)
A. Jain, Toshiba Stroke Research Ctr., Univ. at Buffalo (United States)
D. R. Bednarek, Toshiba Stroke Research Ctr., Univ. at Buffalo (United States)
S. Rudin, Toshiba Stroke Research Ctr., Univ. at Buffalo (United States)


Published in SPIE Proceedings Vol. 8313:
Medical Imaging 2012: Physics of Medical Imaging
Norbert J. Pelc; Robert M. Nishikawa; Bruce R. Whiting, Editor(s)

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