Discovery nm ct 670 czt

Abdominopelvic and thoracic CT was performed with a Discovery NM/CT 670 CZT, a digital SPECT/CT imaging system, including Optima CT540 subsystem (GE Healthcare, Tirat, Hacarmel, Israel). A helical CT tomogram with a modulated mAs (noise index ~30), a rotation time of 0.5 s, 120 kVp, a pitch of 0.938 and 1.25-mm slice thickness was acquired. Soft tissue, bone and lung kernels were employed with a 40% dose reduction in the Adaptive Statistical Iterative Reconstruction (ASIR, GE Healthcare, USA) algorithm. A biphasic contrast-enhanced CT protocol (arterial phase of 10 s, followed by venous phase at 30 s) was performed. Contrast agent (Omnipaque (iohexol)™ GE Healthcare, iodine concentration of 350 mg/ml) was used unless clinical contraindications were present.

SPECT/CT acquisition of the PET NEMA/IEC image quality phantom was performed on a Discovery NM/CT 670 CZT (GE Healthcare, USA) equipped with wide energy high-resolution collimators. All SPECT images were acquired with a list mode. The step and shoot acquisition mode was performed by 360-degree rotations (120 s/6-degree per frame) with a matrix size of 128 × 128 without zoom. Two main energy windows (140 keV ± 7.5% and 140 keV ± 10%) were reconstructed by the list mode to evaluate the impacts of the main energy window on RCs. The scatter energy window was 120 ± 5% keV. CT images were acquired with a 120 kVp tube voltage, 200 mA tube current, matrix size of 512 × 512, and 1.25 mm slice thickness.