Iodine K-edge-enhanced and high-energy imaging using a high-spatial-resolution dual-energy photon-counting x-ray computed tomography scanner.

To sequentially perform iodine (I) K-edge-enhanced and high-energy imaging, we conducted high-spatial-resolution dual-energy photon-counting x-ray computed tomography (PCCT). X-ray photons transmitted through the object were detected using a cadmium telluride flat panel detector, and 720 radiograms were sent to a personal computer to reconstruct 256 tomograms. For I-K-edge-enhanced CT, x-ray photons with energies ranging from 33 to 70 keV were selected. Subsequently, high-energy CT in the 60-100 keV range was performed to reduce metal artifacts and to compare the results with those from I-K-edge CT. Using this cone-beam PCCT scanner, the effective pixel dimensions were 80 × 80 μm2, and fine coronary arteries in a dog-heart phantom were observed at high contrast with I-K-edge CT. In addition, high-energy CT reduced the metal artifact caused by a 0.1-mm-diameter hairpin-shaped tungsten wire.