Flow and peak velocity measurements in patients with aortic valve stenosis using phase contrast MR accelerated with k-t BLAST.

OBJECTIVE

To investigate the accuracy of velocity measurements in patients with aortic valve stenosis using phase contrast (PC) imaging accelerated with SENSE (Sensitivity Encoding) and k-t BLAST (Broad-use Linear Acquisition Speed-up Technique).

METHODS

Accelerated quantitative breath hold PC measurements, using SENSE and k-t BLAST, were performed in twelve patients whose aortic valve stenosis had been initially diagnosed using echocardiography. Stroke volume (SV) and peak velocity measurements were performed on each subject in three adjacent slices using both accelerating methods.

RESULTS

The peak velocities measured with PC MRI using SENSE were -8.0±9.5% lower (p<0.01) compared to the peak velocities measured with k-t BLAST and the correlation was r=0.83. The stroke volumes when using SENSE were slightly higher 0.4±17.1 ml compared to the SV obtained using k-t BLAST but the difference was not significant (p>0.05).

CONCLUSIONS

In this study higher peak velocities were measured in patients with aortic stenosis when combining k-t BLAST with PC MRI compared to PC MRI using SENSE. A probable explanation of this difference is the higher temporal resolution achieved in the k-t BLAST measurement. There was, however, no significant difference between calculated SV based on PC MRI using SENSE and k-t BLAST, respectively.