Exhibit Hall | Forum 9
Purpose: Although interventional CT can provide high-resolution cross-sectional imaging of patient anatomy and interventional devices, it suffers from three major limitations: 1) it can deliver a high radiation dose to both physician and patient, 2) poor image quality, and 3) low imaging speed. We propose to develop a new imaging modality called X-ray-induced acoustic fluoroscopy to address those limitations.
Methods: An X-ray-induced acoustic fluoroscopy system was developed to investigate the potential of real-time reconstruction of needle placement in patients’ body during brachytherapy sessions using X-ray-induced ultrasound waves. Firstly, a 1-inch brachy needle piece was embedded in a tissue mimicking phantom and placed in the radiation beam path of a 150 KvP pulsed X-ray source. The phantom was then radiated by the X-ray source with a single pulse for a duration of 50 nanoseconds. A 256-channel ultrasound transducer array implemented by the X-ray-induced acoustic fluoroscopy system was used to capture the acoustic waves generated from the excited phantom target. A back-projection-based reconstruction was performed to visualize the embedded lead.
Results: The reconstruction of the single X-ray pulse exposure experiment revealed the brachy needle inside of the tissue mimicking phantom. Signal analysis showed that adequate signal-to-noise ratio was achieved from the 50-nanosecond X-ray exposure.
Conclusion: The experiments conducted in this work demonstrated that X-ray-induced acoustic fluoroscopy has 3D imaging capability in real-time, and the limitation for the scanning speed only depends on the pulsing rate of the radiation source. Because of the nature of the XACT-based fluoroscopy system, no additional external radiation is needed for object reconstruction. Therefore, by implementing XACT-based fluoroscopy system for needle placement guidance in brachytherapy sessions can potentially eliminate the extra radiation exposure required for the conventional X-ray-based fluoroscopy.
Funding Support, Disclosures, and Conflict of Interest: This work was supported by the National Institute of Health (R37CA240806), American Cancer Society (133697RSG1911001CCE). The authors would like to acknowledge the support from UCI Chao Family Comprehensive Cancer Center (P30CA062203)