Abstract 12439: Accuracy of Sparse Temporal and Spatial Aortic Pulse Wave Velocity Sampling with Velocity-Encoded MRI: Validation in Patients with Marfan Syndrome
INTRODUCTION: In patients with Marfan syndrome (MFS), increased aortic wall stiffening leads to aortic dissection and premature death. Pulse Wave Velocity (PWV) is a marker of wall stiffness. Dense temporal and spatial PWV-sampling with in-plane velocity-encoded (VE) MRI is the most accurate MRI approach for aortic PWV-assessment. However this method is time-consuming. Conventionally, dense temporal but sparse spatial PWV-sampling with 2-slice through-plane VE MRI is used for PWV-estimation. Improved spatial sampling by 4-slice through-plane VE MRI with sparse temporal sampling might improve accuracy.
HYPOTHESIS: We tested the hypothesis that the 4-slice method is more accurate then the 2-slice method for PWV assessment as compared to the reference standard.
METHODS: 23 MFS patients (13 men, mean age 36±14 years) underwent MRI examination (3T Philips). Three methods were evaluated; (1) reference standard: two-directional in-plane VE with dense temporal (temporal resolution (TR) =9ms) and spatial sampling (2) conventional 2-slice method: two through plane VE acquisitions with dense temporal (TR=10ms) but sparse spatial sampling; (3) accelerated 4-slice method: four VE acquisitions with echo-planar imaging with sparse temporal (TR=23ms) but improved spatial sampling.
RESULTS: When compared with the reference standard for global PWV-assessment in the full aorta, the 4-slice method showed a stronger correlation (R=0.92 vs R=0.65) than the 2-slice method, despite inferior resolution. For regional PWV-assessment in the aortic arch, the accelerated method showed comparable good agreement (R=0.66 vs R=0.67) with the reference standard. Of note, examination time is also shortened 75% by the accelerated method.
CONCLUSION: Despite inferior temporal resolution, accelerated improved spatial 4-slice PWV-sampling better describes aortic stiffness in MFS patients than conventionally-used non-accelerated sparse-spatial 2-slice PWV-sampling.
- © 2011 by American Heart Association, Inc.