Purpose
In recent years, parallel imaging has revolutionized breast MRI. Faster scanning has allowed for more accurate evaluation of contrast kinetics in the breast. However, even faster acquisition times are needed in order to quantitatively assesstissue perfusion and permeability in DCE (dynamic contrast-enhanced) MRI [1, 2]. Parallel imaging factors higher than 3 are rarely used in clinical practice, while higher factors would allow for increased acquisition speed. Improved coil technology and higher magnetic field strengths help overcome the SNR penalty of higher acceleration factors. The goal...
Methods and Materials
The g-factor in sensitivity encoding (SENSE) PIThe availability of an optimized coil array is an essential prerequisite for parallel imaging techniques, as PI makes use of differences in the spatial sensitivity distribution of receiver coil elements to reduce the number of necessary phase-encoding steps required for magnetic resonance imaging, thus shortening the scan time. Most commonly used PI algorithms are SENSE, SMASH and GRAPPA [3] and are subdivided in two domains (k-space/image-space) in which processing is mainly performed. For this project we used the SENSE...
Results
Within an image, the g-factor is dependent on the specific coil array, the spatial location and the acceleration factor. The SNR loss is commonly the main limiting factor in acceleration speed due to rapid growth of the g-factor beyond an acceleration factor of 4 in one direction. However, accelerations in two directions have a multiplicative total acceleration factor that cannot be achieved along one direction without increasing the geometry factor and, hence, the local noise amplification. This would be beneficial on 3D imaging techniques that...
Conclusion
Our results with the 16 channel design indicate that, high quality bilateral breast images with near isotropic resolution can be obtained in as little as 20s at 3T.This opens the door for more detailed analysis of contrast kinetics to aid in predicting response to chemotherapy and improving pharmacokinetic analysis to characterize breast lesions.
References
[1] Moon, M., Cornfeld, D., & Weinreb, J. Dynamic contrast-enhanced breast MR imaging. Magn Reson Imaging Clin N Am 2009; 17:351-62.[2] Yankeelov, T. E., Lepage, M., Chakravarthy, A., Broome, E. E., , K. J., Kelley, M. C., et al. Integration of quantitative DCE-MRI and ADC mapping to monitor treatment response in human breast cancer: initial results. Magn Reson Imaging 2007; 25:1-13.[3] Blaimer, M., Breuer, F., Mueller, M., Heidemann, R. M., Griswold, M. a., Jakob, P. M., et al. Smash, Sense, Pils, Grappa. Top Magn Reson...
Personal Information
Hervé Momo Jeufack, PhDSentinelle Medical555 Richmond St. W. Suite 800Toronto, ON M5V3B1CanadaEmail:
[email protected]