Related Experiment Videos
Estimation of average flow in ungated 3D phase contrast angiograms
S E Maier1, H E Cline, F A Jolesz
1Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Magnetic Resonance in Medicine
|November 1, 1995
Summary
This study demonstrates that average velocity and flow rate can be estimated from ungated 3D phase contrast angiograms. Lower RF tip angles improve accuracy across the entire imaging volume.
Area of Science:
- Medical Imaging
- Cardiovascular Flow Dynamics
- Magnetic Resonance Imaging
Background:
- Three dimensional (3D) phase contrast angiograms (PCA) generate velocity data during imaging.
- This velocity data is typically discarded after image reconstruction.
- Previous research explored velocity quantification using ungated 2D PCA data.
Purpose of the Study:
- To investigate the extraction of average velocity and flow rate from ungated 3D PCA data.
- To evaluate the accuracy of flow rate estimation in 3D PCA.
- To compare 3D PCA flow quantification with 2D PCA methods.
Main Methods:
- Simulations were conducted to model blood flow.
- Experiments were performed using a phantom.
- In vivo experiments were carried out on subjects.
- Analysis focused on ungated 3D phase contrast data.
Main Results:
- Flow rate estimation from ungated 3D PCA is feasible.
- Pulsatile flow and strong spin saturation caused flow rate over/underestimation at inflow/outflow ends.
- Lower radiofrequency (RF) tip angles improved flow rate accuracy throughout the imaging volume.
- Repeated 3D experiments showed consistent flow rate measurements, unlike 2D experiments.
Conclusions:
- Average velocity and flow rate can be usefully estimated from ungated 3D PCA.
- Optimizing RF tip angle is crucial for accurate flow quantification in 3D PCA.
- 3D PCA offers reproducible flow rate measurements compared to 2D PCA.