Aquilion one genesis

Each phantom, with contrast rod in situ, was scanned using a SECT scanner. Phantom imaging and reconstruction parameters for a GE Revolution Apex (GE Healthcare, Waukesha, WI, USA), referred to as SECT scanner A, and a Toshiba Aquilion One Genesis edition (Canon Medical, Otawara, Japan), referred to as SECT scanner B, are listed in Table 1. CTDI_vol was matched across both SECT systems for each phantom size respectively. Each phantom acquisition was reconstructed using ASiR‐V (Standard kernel, 50% setting, GE Healthcare) and statistical based iterative reconstruction (SBIR), AIDR3D (FC‐18H kernel, standard setting, Canon Medical). All images were then retrospectively reconstructed using deep learning reconstruction (DLR) algorithms: TrueFidelity (Medium setting, GE Healthcare) and AICE (Standard Body setting, Canon Medical).

All CT angiography examinations were performed on a 320-row CT scanner (Aquilion ONE Genesis, Canon Medical System). Nonionic iodine contrast agent (370 mg/ml) was intravenously injected with the dosage of 0.6 ml/kg, followed by 30 ml saline with a two-channel high-pressure injector. After contrast injection, two phases scanning of CT angiography was performed, including the arterial phase and delayed phase. Arterial-phase scanning parameters: the monitoring layer was located at the middle level of common carotid artery with manually triggered; tube voltage 120 kV, automatic milliampere. The delayed-phase scanning parameters: 150 s after injection of contrast agent, automatic trigger scanning, tube voltage of 120 kV, automatic milliampere. The scanning range of both phases was the same, from the aortic arch to the sellar with slice thickness of 1 mm.
The BBCT images were obtained by subtracting the arterial-phase images from the delayed-phase images using the analysis software installed in the CT workstation (Aquilion ONE, Canon Medical Systems).

All CT examinations were performed with a 320-detector row CT scanner (Aquilion ONE GENESIS, Canon Medical). For each CT, the main parameters were as follows: helical acquisition, 0.5 mm × 80 rows; beam pitch, 0.813; gantry rotation time, 0.35 s; matrix, 512 × 512; and field of view, 320 mm. Tube voltage was 120 kVp, 100 kVp, or 80 kVp. Automatic tube-current modulation (SUREExposure™ 3D, Canon Medical) was used for all CTs. The noise-index settings were based on our initial experience in clinical practice and on the manufacturer’s recommendations. Reconstruction parameters were 1.0-mm slice thickness and 0.8-mm gap. Table 1 lists the acquisition and reconstruction parameters. In accordance with our standard CTA protocol involving subtraction, all patients received a fixed 65-mL intravenous bolus of Iomeron, 350 mg iodine per mL (Bracco Imaging, Courcouronnes, France), followed by a 50-mL bolus of saline at an injection rate of 4 mL/s for both. Image acquisition was triggered using a predefined threshold of aortic-arch attenuation. Each CT scan was reconstructed using both H-IR (AIDR 3D) with a standard FC43 kernel and DLR with beam-hardening correction (AiCE Body Sharp).

Experiments were carried out in both the phantom and patient studies. A commercial CT scanner (Aquilion ONE GENESIS, Canon Medical Systems, Otawara-shi, Japan) capable of FBP, IR, and DLR was used for image acquisition. In this study, a tube voltage of 100 kV was used to reduce beam-hardening artifacts according to body mass index (BMI). Slice thickness is 0.5 mm, and image matrix is 512 × 512. After CT scan, images were reconstructed using FBP, IR, and DLR, respectively.

Two different CT scanning protocols were used for comparing image quality, reconstruction time as well as radiation dose. All examinations were performed on a 320-slice multidetector CT scanner (Aquilion ONE Genesis, Canon Medical Systems, Otawara, Japan). Technical parameters were: tube voltage of 120 kV, modulated tube current (100–700, SD = 10), rotation time of 0.275 s, pitch factor of 0.814, and collimated slice thickness of 80 mm × 0.5 mm.