Real-time interactive duplex MR measurements: application in neurovascular imaging.

Area of Science:

• Medical Imaging
• Cardiovascular Imaging
• Neuroimaging

Background:

• Phase-contrast MR imaging (PC-MRI) is crucial for assessing blood flow.
• Cardiac gating is typically required for accurate PC-MRI.
• A novel real-time interactive duplex MR imaging technique has emerged.

Purpose of the Study:

• To evaluate the feasibility and reliability of real-time interactive duplex MR imaging.
• To assess hemodynamic information in vitro and in vivo.
• To investigate its application in carotid arteries and venous sinuses.

Main Methods:

• Real-time duplex MR measurements were performed using specific parameters (TR/TE, 53/27; flip angle, 90 degrees; encoding velocity, 100 or 150 cm/sec).
• Studies included a steady-flow phantom and 10 healthy volunteers measuring carotid artery and superior sagittal sinus velocities.
• Data were compared with conventional PC-MRI and Doppler sonography.

Main Results:

• High in vitro (0.99) and moderate in vivo correlations (0.83 carotid, 0.76 venous sinus) were observed between real-time duplex MR and conventional PC-MRI.
• Real-time MR showed significantly lower velocity measurements in carotid arteries compared to conventional PC-MR and sonography, attributed to volume averaging.
• Reliable identification of velocity changes in the venous sinus during hyperventilation was achieved with both MR techniques.

Conclusions:

• Real-time interactive duplex MR imaging is a feasible and reliable technique for neurovascular imaging.
• It effectively quantifies hemodynamic information in real time.
• This method holds promise for clinical applications in assessing blood flow.