Yun Shang1, Sebastian Theilenberg1, Laura M. Schreiber2,3, and Christoph Juchem1,4
1Department of Biomedical Engineering, Columbia University, New York, NY, United States, 2Chair of Cellular and Molecular Imaging, Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg, Germany, 3Department of Cardiovascular Imaging, Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg, Germany, 4Department of Radiology, Columbia University Medical Center, New York, NY, United States
1Department of Biomedical Engineering, Columbia University, New York, NY, United States, 2Chair of Cellular and Molecular Imaging, Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg, Germany, 3Department of Cardiovascular Imaging, Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg, Germany, 4Department of Radiology, Columbia University Medical Center, New York, NY, United States
B0 simulation error adopting FFT-based method converged starting from a zero-padding factor of 2-3. Higher spatial resolution led to more accurate fields distribution. Anatomical extension of CT-derived FOV from a body with similar BMI allows to elevate B0 field accuracy with lowest error.
Figure
2. Comparison of simulated B0 fields in the heart between the FFT-based
method and dipole method. A) Exemplary field distribution in the heart was
calculated using dipole method based on the susceptibility distribution of Ella’s
entire body at 3 mm isotropic. The
standard deviation of the field difference was shown B) from fine to coarse resolution
and C) a range of zero-padding factors. Zero-padding
factors higher than 2.5 do not substantially improve the STD value, i.e., B0
accuracy, while a higher resolution can significantly lower this value (dash line: linear fit at zf = 2.5).
Figure 5. The standard deviation of field
difference between the extended CT-derived FOV and the entire body for ten female models (left) and ten male models (right). The anatomical extension type 3 adopting the body
with a similar BMI exhibited the lowest B0 simulation error compared
to other types, especially in male models. It is the optimized strategy when sufficient computation power is
available while simplified anatomical extension type 4 are reasonable compromises to
achieve high-resolution B0 simulation with less discretization
error under limited computation resources.
