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Biomedical subjects

Philip T Komljenovic

Publications and source records attributed to Philip T Komljenovic.

3 recordsLinked to original sources

A lesion stabilization method for coronary angiography.

A method to make a coronary artery segment of interest appear stationary when viewing a sequence of angiographic images is proposed. The purpose of this method is to facilitate the assessment of lesions caused by coronary artery disease by improving detectability. A description of the stabilization algorithm based on template matching is given. Stabilization was performed on 41 clinical coronary angiograms exhibiting various stenoses and was successful in 39/41 cases. A quantitative analysis of stabilization errors was performed by introducing simulated moving vessels of decreasing contrast into sequences of clinical images.

Algorithms↗

Real-time image equalization for coronary X-ray angiography.

Coronary angiograms, which provide detailed images of contrast-filled coronary arteries, also show other large structures such as the diaphragm, spine and adjacent lung field. A real-time image processing method to attenuate these unwanted features is presented. Side-by-side comparisons of images selected from cine runs before and after processing show that the arteries in the processed images can be visualized more easily due to their higher contrast as other structures are made less prominent. It is also shown experimentally that this method allows more quantitative comparisons of the contrast of vessels in different parts of an image.

Angiography, Digital Subtraction↗

A filtering method for signal equalization in region-of-interest fluoroscopy.

A method to significantly reduce the exposure area product in fluoroscopy using a pre-patient region-of-interest (ROI) attenuator is presented. The attenuator has a thin central region and a gradually increasing thickness away from the center. It is shown that the unwanted brightening artifact caused by the attenuator can be eliminated by attenuating the low spatial frequencies in the detected image using digital image processing techniques. An investigation of the best image processing method to correct for the presence of the attenuator is undertaken. The correction procedure selected is suitable for use with real-time image processors and the ROI attenuator can be permitted to move during image acquisition. Images of an anthropomorphic chest phantom acquired in the presence of the ROI attenuator using an x-ray image intensifier/video chain are corrected to illustrate the clinical feasibility of our approach.

Biophysical Phenomena↗