oaioai:figshare.com:article/6449450

3D Dataset "Computation of Exact g-Factor Maps in 3D GRAPPA Reconstructions"

Abstract

<p>Datasets used in the paper entitled "", containing the following acquisitions:</p> <p>    <strong>1) Simulated abdomen data set</strong>: we have synthetized a 3D volume using the simulation environment XCAT based on the extended cardio-torso phantom. We simulated a T1-weighted acquisition using the following acquisition parameters: TE/TR=1.5/3ms, flip angle=60º, acquisition matrix size=60x60x32. A 32-coil acquisition was simulated by modulating the image using artificial sensitivity maps coded for each coil. The noise-free coil images were transformed into the \bk--space and corrupted with synthetic Gaussian noise characterized by the matrices Γk\Gamma_kand CkC_k with SNR=25 for each coil, and the correlation coefficient between coils was set to ρ\rho=0.1.Forstatisticalpurposes,4000realizationsofeachimagewereused.</p><p><br>   <strong>2)Waterphantomacquisition</strong>:AMRphantomspherewithsolution(GEMedicalSystems,Milwaukee,WI)wasscannedina32channelheadcoilona3.0Tscanner(MR750,GEHealthcare,Waukesha,WI).Aspoiledgradientechoacquisitionwith100realizationsofthesamefullyencodedkspacesamplingwasused.Acquisitionparametersincluded:coronalview,TE/TR=0.96/3.69ms,flipangle=12º,fieldofview=22x22. For statistical purposes, 4000 realizations of each image were used.</p> <p><br>     <strong>2) Water phantom acquisition</strong>: A MR phantom sphere with solution (GE Medical Systems, Milwaukee, WI) was scanned in a 32-channel head coil on a 3.0T scanner (MR750, GE Healthcare, Waukesha, WI). A spoiled gradient-echo acquisition with 100 realizations of the same fully-encoded k-space sampling was used. Acquisition parameters included: coronal view, TE/TR=0.96/3.69ms, flip angle=12º, field of view=22x22x30.7cm3cm³, acquisition matrix size=60x60x32, bandwidth=62.5KHz. We corrected for B0B_0 field drift related phase variations and magnitude decay by a pre-processing step. First we estimated the phase-shift between realizations from the center of the k-space as a cubic function of time and removed it afterwards. And, second, we estimated the magnitude-decay in the k-space as a linear function and substracted it in order not to affect the noise.</p> <p><br>     <strong>3) In vivo acquisition</strong>: in order to assess the feasibility of the proposed method, after obtaining the approval fo the local institutional review board (IRB), a volunteer was scanned in a 32-channel head coil on a 3.0T scanner (MR750, GE Healthcare, Waukesha, WI). A spoiled gradient-echo acquisition of a fully-encoded \bk--space sampling was used. Acquisition parameters included: coronal view, TE/TR=2.2/5.7ms, flip angle=12º,field of view=22x22x22cm3cm³, matrix size=220x220x220, bandwidth=62.5$KHz.</p

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oaioai:figshare.com:article/6449450Last time updated on 8/13/2018

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