Room: Exhibit Hall | Forum 8
Purpose: Dynamic x-ray detectors typically operate at tens of frames per second; however, such low temporal resolution is unable to resolve vascular flow detail. A single-photon counting detector (PCD) operating at 1000 fps was used to explore ultra-high frame rate imaging in resolving previously unseen vascular flow dynamics in vivo.
Methods: Flow detail was observed for the cardiovascular anatomy in a New Zealand rabbit model. Iodine-based contrast was injected manually and imaged with the CdTe-based Actaeon detector by XCounter, with 100 um 256x256 pixel active area. High temporal resolution was achieved at 1000 fps for a series of six 83 ms sequences, which were each temporally separated by 84 ms. The â€œAnti-Coincidence Onâ€? (ACC On) circuitry was used to correct for charge sharing from adjacent pixels. The angiographic C-arm was operated in DSA mode with technique parameters set to 70 kVp, 320 mA, medium focal spot, and 6 pulses per second each with a 83 ms pulse length matched to the duration of each of the sequences.
Results: Examination of the image sequences illustrates detailed flow dynamics made available through use of the ultra-high frame rate enabled detector. The iodine-based contrast agent was clearly seen above background anatomy entering the left ventricle through the aortic valve. Contrast can subsequently be seen in the background moving down the descending aorta.
Conclusion: The experiment indicates the potential for identifying useful hemodynamic information that may offer new insight into the evaluation and diagnosis of cardio and neurovascular disease states. This initial experience with ultra-high frame rate imaging has set the groundwork for further investigation into flow dynamics of common pathologies including vessel stenosis, aneurysm, and valve regurgitation.
Funding Support, Disclosures, and Conflict of Interest: This research was supported in part by Canon Medical Systems.
Flow Imaging, Flow Velocity, High-resolution Imaging