Ryan Egeland

Publications of Ryan Egeland

• Inherently 3-dimensional method for measurement of computed tomographic resolution anisotropy.

  Authors: Stephen E Jones, Michael Grasruck, Bernhard Schmidt, Ijad Madisch, Ryan Egeland, Tom Brady, Rajiv Gupta

  Journal of computer assisted tomography. 30(6):962-71.

  OBJECTIVE: Current techniques to measure computed tomography (CT) spatial resolution use separate methods for in-plane and out-of-plane directions. The growing use of near-isotropic voxel sizeOBJECTIVE: Current techniques to measure computed tomography (CT) spatial resolution use separate methods for in-plane and out-of-plane directions. The growing use of near-isotropic voxel size necessitates a new single method that inherently measures resolution in any direction. METHOD: We introduce a method using a set of numerous glass microspheres suspended in a small volume from which a mean sphere image is constructed. Projecting asymptotes after imaging different microsphere sets with decreasing diameters provides an inherently 3-dimensional measure of spatial resolution and anisotropy. We apply the method to both a flat-panel and multidetector CT scanner. RESULTS: The full-width at half-maximum from line profiles through mean sphere in transverse directions corresponds to known microsphere diameters. Increased longitudinal full-width at half-maximum corresponds to known anisotropy, which is larger for a multidetector CT scanner than for a flat-panel CT scanner. CONCLUSIONS: A new single method to measure CT resolution is inherently isotropic.

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