John Meinel MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: The purpose is to present an axiomatic method for measuring 3D resolution, image noise, and their variation over the FOV of a micro-CT scanner. Methods and Materials: We designed a small disk phantom (D = 50mm, base HU = 0), containing 33 metallic spheres (D = 0.5mm, HU = 2000) that are co-planar. There was one sphere at the iso-center, and the rest were placed in four concentric rings (D = 10, 20, 30, 40mm). The phantom was scanned with commercially available micro-CT scanners. According to a recently developed resolution theory, an appropriate measure of image resolution in multi-dimensions should be proportional to the square-root of the trace of the covariance matrix of the point spread function (PSF). Based on this definition, we developed a PC software package to automatically segment the high contrast spheres, and compute the resolution and noise at the location of each sphere. Results: The phantom enabled a single-scan measurement of the distribution of spatial resolution and image noise with any micro-CT scanner, which was depicted as a function of the radial distance within the FOV. Both 3D resolution, directional resolutions, image noise, and resolution-to-noise ratios, were quantified. There were significant differences between the resolution and noise in the iso-center and that in the outer rings. In general, the scanners performed similarly. Their differences were quantified as well. Conclusion: We have extended our methodology to measure the variation of 3D resolution and image noise with micro-CT, and quantified the resolution and noise distributions for micro-CT scanners. Our results have improved the understanding of the image quality variation, and are valuable for high resolution micro-CT applications.       Questions about this event email: john-f-meinel@uiowa.edu

Meinel MD, J, Variation of 3D Resolution and Image Noise with Micro-CT.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3103720.html