Purpose: Recent advances in photon counting detector (PCD) technology have prompted the evaluation of a new PCD in performing ultra-high frame rate imaging at 1000 fps. Parameters of significance explored in this experiment include the employment of various catheter designs, synchronization with a contrast injector, and signal thresholding.
Methods: The above parameters were evaluated using a 3D printed patient-specific saccular aneurysm phantom and iodine-based contrast media. The XCounter Actaeon PCD utilized for this experiment has a 0.75-mm thick CdTe converter layer with a pixel pitch of 100 Î¼m, and a 256 by 256 active area. The Actaeon PCD was operated in anti-coincidence mode, with a 20 keV signal threshold that allowed for the acquisition of images with negligible instrumentation noise. Several catheter designs and sizes were compared. Images were acquired at 1000 fps, with varying volumes of contrast and injection triggering techniques. The mobile C-arm technique parameters were set at 70 kVp and 100 mA, with a 3-s exposure time.
Results: The XCounter Actaeon was utilized to demonstrate the effectiveness of PCDâ€™s in performing ultra-high frame rate imaging with varying contrast injection parameters. Imaging at 1000 fps provides visualization of detailed flow patterns which have never been seen before in a clinical-like setting. Subsequent passive contrast flow rates (without the influence of the mechanical injector) out of each catheter tip were determined, which ranged from approximately 12-30 cm/s depending on the injection conditions and catheter design.
Conclusion: The Actaeon PCD can achieve high temporal resolution at 1000 fps, as well as enhanced spatial resolution due to ACC and signal thresholding. This implications of combining these three features in a research or clinic-like setting may allow the characterization of flow using specific catheter models, and aid in catheter choice during treatment of vascular abnormalities.
Funding Support, Disclosures, and Conflict of Interest: This research was supported in part by Canon Medical Systems.