Quantitative Digital Subtraction Angiography Measurement of Arterial Velocity at Low Radiation Dose Rates.

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Radiology

Background:

• Quantitative digital subtraction angiography (qDSA) is a technique for measuring blood velocity.
• High frame rate imaging (around 30 frames per second) is typically required for qDSA.
• Clinical translation of qDSA is limited by radiation exposure concerns.

Purpose of the Study:

• To investigate the performance of qDSA in low radiation dose acquisitions.
• To assess the feasibility of using qDSA for monitoring blood flow interventions with reduced radiation exposure.

Main Methods:

• Evaluated velocity quantification accuracy across five radiation dose rates, both in vitro and in vivo.
• Utilized a 30 fps digital subtraction angiography protocol, with dose rates ranging down to 23% higher than standard fluoroscopy.
• Compared angiography-based velocity measurements with ANOVA and Bland-Altman analysis in a swine hepatic arterial model and a swine study.

Main Results:

• Achieved radiation dose rate reductions of 99% (phantom) and 96% (swine) for the lowest dose protocol.
• Found no significant difference in velocity measurements across dose rates in vitro or in vivo.
• Observed minimal bias (range: [-0.1, 0.1] cm/s) with acceptable limits of agreement in lower-dose protocols.

Conclusions:

• Demonstrated the feasibility of quantitative blood velocity measurements using qDSA with reduced radiation doses.
• Supports the clinical translation of qDSA for monitoring interventions by lowering radiation exposure.