PROCEEDINGS ARTICLE | March 25, 2016
Proc. SPIE. 9783, Medical Imaging 2016: Physics of Medical Imaging
KEYWORDS: Photon counting, X-ray computed tomography, Imaging systems, Sensors, Scanners, Heart, Lung, Bone, Image quality, Computed tomography, Modulation transfer functions, Spatial resolution
A high-resolution (HR) data collection mode has been introduced to a whole-body, research photon-counting-detector
CT system installed in our laboratory. In this mode, 64 rows of 0.45 mm x 0.45 mm detector pixels were used, which
corresponded to a pixel size of 0.25 mm x 0.25 mm at the iso-center. Spatial resolution of this HR mode was quantified
by measuring the MTF from a scan of a 50 micron wire phantom. An anthropomorphic lung phantom, cadaveric swine
lung, temporal bone and heart specimens were scanned using the HR mode, and image quality was subjectively assessed
by two experienced radiologists. High spatial resolution of the HR mode was evidenced by the MTF measurement, with
15 lp/cm and 20 lp/cm at 10% and 2% modulation. Images from anthropomorphic phantom and cadaveric specimens
showed clear delineation of small structures, such as lung vessels, lung nodules, temporal bone structures, and coronary
arteries. Temporal bone images showed critical anatomy (i.e. stapes superstructure) that was clearly visible in the PCD
system. These results demonstrated the potential application of this imaging mode in lung, temporal bone, and vascular
imaging. Other clinical applications that require high spatial resolution, such as musculoskeletal imaging, may also
benefit from this high resolution mode.
