An investigation of the spatial resolution properties of MiniCAT: Flat panel-based volume CT system for head and neck imaging

Purpose: Volume computed tomography (VCT) using flat panel detectors has the capability to provide isotropic high spatial resolution, whereas traditional multislice scanners often exhibit decreased spatial resolution in the axial direction. In many clinical applications including temporal bone imaging, reformatted images reviewed for diagnostic purposes and anisotropic resolution can reduce the clinical utility of such views. We present a spatial resolution investigation of the MiniCAT system, a commercially available flat‐panel‐based VCT system made by Xoran Technologies, Inc. and compare spatial resolution with a traditional multislice CT (MSCT) system (Siemens Sensation 16) using standard acquisition protocols. Method and Materials: We investigate the spatial resolution properties of the flat‐panel‐based VCT and traditional MSCT using line pair phantoms and a comparison of scanned human temporal bones. Graded line pair phantoms are scanned in three orientations to provide resolution measures along each axis (X,Y, and Z). The modulation transfer function (MTF) of the MiniCAT system is computed using conventional techniques. Human temporal bone scans are analyzed qualitatively and clarity of various fine detail features is assessed. Results: We find the spatial resolution of the MiniCAT system to be highly isotropic with an MTF that yields 10% contrast at 17 lp/cm. In the qualitative image quality study we find that fine feature details in the temporal bone like the bone overlying the tympanic section of the facial nerve canal are better resolved using the flat‐panel‐based VCT system than in the traditional MSCT. Conclusion: Flat‐panel‐based VCT can provide finer isotropic resolution than traditional MSCT which may give it an advantage in clinical diagnosis — particularly when looking at small details in oblique views as is common in the diagnosis of otologic pathology. Conflict of Interest: Research sponsored by Xoran Technologies, Inc. © 2007, American Association of Physicists in Medicine. All rights reserved.