0352
View Abstract / View Presentation
Liver Stiffness in a Single Breath-hold Using Wave Polarity-Inversion Motion Encoding and Compressed SENSE: Coverage Equivalent to 5 Slices
Amol Pednekar1, Deep B. Gandhi2, Hui Wang3, Jean A. Tkach1, Andrew T. Trout1, and Jonathan R. Dillman1
1Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 3MR Clinical Science, Philips, Cincinnati, OH, United States
In 19 volunteers, mean liver shear stiffness values measured with SC_2D_4BH and 3D_5sl_SBH correlated very strongly (ICC=0.96) with mean bias of 0.13 kPa (<5%). 3D_5sl_SBH MRE provides similar stiffness estimates as SC_2D_4BH with increased coverage in a single breath.
Figure 1: Schematic pulse sequence diagrams. (A) SC_2D_4BH: The polarity of MEGs is reversed (blue and yellow) every RF excitation. The mechanical wave polarity (green) stays the same across RF excitations. Each RF excitation triggers 3 motion cycles. (B) 3D_5sl_SBH : The polarity of MEGs remains the same (blue) across RF excitations. The mechanical wave polarity inverts (green and red) every RF excitation. Every 4th RF excitation triggers 7 motion cycles. Each sequence starts with dummy excitation of 1 s that ensures both acoustic and magnetization steady-state.
Figure 3: Comparison of liver shear stiffness values in individual slices for SC_2D_4BH and 3D_5sl_SBH techniques by Linear Regression and Bland-Altman Analysis. Values are based on manual analysis informed by a 95% confidence mask with matching ROIs on images from both techniques and maximal possible ROI in each. SC_2D_4BH: standard of care two-dimensional 4 slices through mid-liver with 13 second breath-hold per slice; 3D_5sl_SBH: 3D wave polarity-inversion motion encoding plus compressed SENSE acquisition in single breath-hold of <16s.