Eleni A. Liapi MD, Presenter: Research grant, ContextVision AB

Christos S. Georgiades MD, PhD, Abstract Co-Author: Nothing to Disclose

Kelvin Hong MD, Abstract Co-Author: Speaker, Boston Scientific Corporation

Fredrik Olofsson MS, MEng, Abstract Co-Author: Employee, ContextVision AB

Donald Barry PhD, Abstract Co-Author: Employee, ContextVision, AB

Jean-Francois H. Geschwind MD, Abstract Co-Author: Grant, Boston Scientific Corporation Grant, Genentech, Inc Grant, Biocompatibles International plc Grant, MDS Inc Consultant, Biocompatibles International plc Consultant, MDS Inc Consultant, Terumo Corporation Consultant, BioSphere Medical, Inc Patent holder, 3-BrPa for Targeting Tumor Metabolism

To test and determine on a porcine model the effect of a novel real-time imaging adaptive filter that can be applied during interventional radiological procedures on image quality, vessel and structure conspicuity and characterization and reader confidence on low dose digital angiographic imaging.

Three types of digital angiograms (aortic, renal and hepatic) were acquired at both standard (160-200 mA, 80 Kv) and one-half radiation (63-125mA, 80 Kv) doses in a CCD camera angiography unit. Low dose angiograms were processed with a dynamic filter (ContextVision, Stockholm, Sweden) based on anisotropic noise suppression and pixel image enhancement. Standard, original and filtered one-half dose angiograms were de-identified, randomized and reviewed by two radiologists for image noise, contrast, visibility of large, small and neighboring vessels, visibility of spinal structures, presence of artifacts and overall diagnostic acceptability on a five point scale (1=excellent; 5=worst). Interobserver reader variability was also measured and set as acceptable if κ>0.7.

The addition of the real-time adaptive filter in all low dose angiograms lead to significant improvement in both subjective (p<0.0.5) and quantitative SNR (p<.001) without any decrease in contrast and visibility of small and neighboring vessels (p>.05). Moreover, filtered low radiation dose angiograms were comparable to standard radiation dose angiograms in terms of visibility of large, small and neighboring vessels, visibility of spinal structures, presence of artifacts and overall diagnostic acceptability (p>0.5). Interobserver agreement was high for all comparisons (κ range: 0.83-0.94).

This novel real-time imaging adaptive filter may help decrease qualitative and quantitative SNR in low radiation dose digital angiograms without compromising on image quality and structure conspicuity. Moreover, filtered low radiation dose angiograms have comparable image quality and diagnostic acceptability to high radiation dose angiograms, leading to up to 50% decrease in radiation dose during interventional procedures.

This novel real-time imaging adaptive filter can help reduce radiation dose for digital angiography examinations by as much as 50% without compromising image quality and diagnostic acceptability.

Liapi, E, Georgiades, C, Hong, K, Olofsson, F, Barry, D, Geschwind, J, The Effect of a Novel Real-time Adaptive Filter on Radiation Dose Reduction during Interventional Radiologic Procedures: Initial Evaluation on a Porcine Model.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8014858.html