Volker Rasche PhD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To compare the volume imaging performance of flat-panel X-ray detectors (FPD) and image-intensifiers (II) on commercial interventional C-Arc X-Ray systems. Methods and Materials: The performance of the different systems for volume imaging was compared in terms of three-dimensional spatial resolution (3D-MTF), contrast resolution, geometrical accuracy and homogeneity depending on the detector resolution, focal spot size, number of projections and the angular span covered during the data acquisition. The different quantities were assessed utilizing a standardized CT image quality phantom (Catphan500, The Phantom Laboratory, Cambridge, USA), a dedicated spatial resolution phantom and a pelvis phantom (IMRT Pelvis Phantom Model 002PRA, CIRS, Norfolk, USA). 2D projections were acquired during rotational angiography mode on a high precision bench-top system and a commercial interventional C-Arc system both equipped with a 176x176 mm2 active area FPD (Trixell Pixium 4800), and a commercial interventional C-Arc system equipped with a 38cm II. The number of projections used for the reconstruction varied between 100 and 750. Data reconstruction was performed by a slightly modified Feldkamp reconstruction technique. Results: In direct comparison, the performance of the FPD with respect to the isotropic spatial resolution and contrast resolution is clearly superior to the image intensifiers. Spatial resolutions of up to 30lp/cm at 10% modulation could be achieved with the FPD, whereas the upper limit for the II was in the order of 25lp/cm. Utilizing the FPD results in maximal contrast resolution below 10HU, whereas the limit in case of the II was in the order of 25 HU. With respect to homogeneity and geometrical accuracy no significant differences could be observed. The high spatial resolution enabled the visualization of the ossicles including the stirrup bone on both systems. Conclusion: The study clearly showed that both, image intensifier- and flat panel detector- equipped interventional C-Arc systems, can be applied for high quality volume imaging. The better dynamic range and spatial resolution of the FPD results in improved spatial and contrast resolution. However, for many applications, II-based solutions provide already sufficient image quality. (V.R., B.S., D.S. are employees of Philips Research. P.V., N.N. are employees of Philips Medical Systems. J.W. received a grant from Philips Research.) Questions about this event email: Volker.Rasche@philips.com

Rasche PhD, V, Comparison of Flat Panel Detectors and Image Intensifiers for Volume Imaging on Interventional C-Arc Systems.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3107136.html