Meeting Banner
Abstract #4270

Fast Isotropic Volumetric B1+ Calibration Improves RF Shimming in Abdominal MRI at 3T

Alois M. Sprinkart1, 2, Georg Schmitz2, Frank Trber1, Wolfgang Block1, Jrgen Gieseke3, Winfried A. Willinek1, Hans H. Schild1, Peter Brnert4, Kay Nehrke4

1Dept. of Radiology, University of Bonn, Bonn, Germany; 2Institute of Medical Engineering, Ruhr-University Bochum, Bochum, Germany; 3Philips Healthcare, Hamburg, Germany; 4Philips Research Laboratory, Hamburg, Germany

The recently published ultra-fast B1+ mapping approach DREAM was used to acquire an volumetric B1+ calibration dataset of the whole upper abdomen with an isotropic voxel size of 4.7mm within a single breath-hold acquisition in 12 patients and 2 volunteers at 3T. Based on this data RF settings were optimized separately for each of 60 transversal and 40 coronal reformatted slices, adaptive to position and angulations to evaluate potential improvements in flip angle accuracy and B1+ homogeneity by multi-slice adapative RF shimming. Results were compared to conventional transversal single-slice optimization approach.

Abstract PDF Presentation Video

Keywords

abdomen abdominal accuracy acquisition acquisitions adaptive advanced allows already amplitude amplitudes analyzed application applied applying axial benefit best block blue bottom breath calibration central channel channels chosen clinical coefficient column compute computed consent coronal crosses currently dept determination deviation displayed double dream dual duration echoes engineering essential evaluations examination excitation extensive fast female field frank green hamburg healthy hold homogeneity improve improved improvement improvements improves included individually informed institute irrespective isotropic iterative laboratory least long magnetization magnitude male mapping medical nominal oblique optimal optimization optimized orientation parallel patient patients peter pixels position positioned potential preparation prolongation proposed prospective pulses quantitative radiology reduces reduction referred reformats reformatted regional respectively restricted revealed scheme sense sets settings shim shimming shot significantly slice slices sophisticated source square squares steam strategies strategy subsequent subsequently substantially system target timing torso transmit transversal triangle ultra uniformity upper utilized utilizing variation versus volume volumetric volunteers water whole written year