Real time blood flow imaging by spiral scan phase velocity mapping

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular Physiology

Background:

• Accurate real-time blood flow velocity measurement is crucial for cardiovascular assessment.
• Existing techniques can suffer from signal loss and artifacts.
• Rapid imaging methods are needed to capture dynamic flow changes.

Purpose of the Study:

• To develop and validate a novel real-time flow velocity imaging technique.
• To assess the performance of this technique in phantoms and in vivo.
• To explore potential clinical applications of the new method.

Main Methods:

• Development of a novel imaging sequence combining rapid spiral k-space sampling and phase velocity mapping.
• Phantom studies for through-plane and in-plane flow assessment.
• In vivo studies in normal volunteers, including cine velocity mapping and response to exercise and Valsalva maneuver.

Main Results:

• The technique demonstrated accurate flow measurements compared to conventional methods.
• Minimal flow-related signal loss was observed due to early k-space center acquisition.
• In vivo aortic flow waveforms correlated well with conventional gradient-echo sequences.
• Flow artifacts for in-plane flow were identified and explained via simulations.

Conclusions:

• The novel spiral imaging technique provides accurate and robust real-time flow velocity mapping.
• The method has minimal signal loss and potential for wide clinical applicability.
• Demonstrated utility in assessing physiological responses like exercise and the Valsalva maneuver.