Verifying the Accuracy of Hemodynamic Analysis Using High Spatial Resolution 3D Phase-contrast MR Imaging on a 7T MR...

Area of Science:

• Medical Imaging
• Biophysics
• Fluid Dynamics

Background:

• Hemodynamics plays a critical role in the initiation, growth, and rupture of intracranial aneurysms.
• Accurate hemodynamic analysis of small intracranial aneurysms requires high spatial resolution and high signal-to-noise ratio (SNR) MRI.

Purpose of the Study:

• To compare the accuracy of MR fluid dynamic (MRFD) analysis derived from 7T MRI data versus 3T MRI data.
• To evaluate the performance of a 7T MR system for hemodynamic analysis in a cerebrovascular phantom and healthy subjects.

Main Methods:

• 3D phase-contrast MR (3D PC MR) and 3D time-of-flight MR angiography (3D TOF MRA) were acquired on both 3T and 7T MR systems.
• MR fluid dynamic (MRFD) analysis was performed on the acquired data.
• MRFD results were compared against computational fluid dynamics (CFD) using correlation coefficient (R), angular similarity index (ASI), and magnitude similarity index (MSI).

Main Results:

• The 7T MR system produced MRFD results with less noise near vascular walls compared to the 3T system, closely matching CFD.
• Higher correlation coefficients (R), ASI, and MSI were observed for the 7T MR system in both phantom and human subject data.
• Significant differences in ASI and MSI were found between the 7T and 3T systems in healthy human subjects.

Conclusions:

• The accuracy of MR fluid dynamic (MRFD) analysis is superior using a 7T MR system compared to a 3T MR system.
• High spatial resolution MRFD analysis benefits significantly from the capabilities of ultra-high-field MRI (7T).