Accelerated dynamic MRI using patch regularization for implicit motion compensation.
To introduce a fast algorithm for motion-compensated accelerated dynamic MRI.



An efficient patch smoothness regularization scheme, which implicitly compensates for inter-frame motion, is introduced to recover dynamic MRI data from highly undersampled measurements. The regularization prior is a sum of distances between each rectangular patch in the dataset with other patches in the dataset using a saturating distance metric. Unlike current motion estimation and motion compensation (ME-MC) methods, the proposed scheme does not require reference frames or complex motion models. The proposed algorithm, which alternates between inter-patch shrinkage step and conjugate gradient algorithm, is considerably more computationally efficient than ME-MC methods. The reconstructions obtained using the proposed algorithm is compared against state-of-the-art methods.



The proposed method is observed to yield reconstructions with minimal spatiotemporal blurring and motion artifacts. In comparison to the existing state-of-the-art ME-MC methods, PRICE provides comparable or even better image quality with faster reconstruction times (approximately nine times faster).



The presented scheme enables computationally efficient and effective motion-compensated reconstruction in a variety of applications with large inter-frame motion and contrast changes. This algorithm could be seen as an alternative over the current state-of-the-art ME-MC schemes that are computationally expensive. Magn Reson Med 77:1238-1248, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Department of Electrical and Computer Engineering, the University of Iowa, Iowa, USA.
Yasir Q
YQ
Mohsin
Department of Electrical Engineering, University of Southern California, California, USA.
Sajan Goud
SG
Lingala
Department of Radiology, the University of Utah, Utah, USA.
Edward
E
DiBella
Department of Electrical and Computer Engineering, the University of Iowa, Iowa, USA.
Mathews
M
Jacob
D000465:Algorithms; D016477:Artifacts; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
CINE; dynamic MRI; free-breathing; motion compensation; motion estimation; myocardial perfusion; patch regularization; shrinkage