CommunicationHigh-Precision Mapping of the Magnetic Field Utilizing the Harmonic Function Mean Value Property
References (24)
- et al.
J. Magn. Reson.
(1988) - et al.
J. Magn. Reson. B
(1996) - et al.
Magn. Reson. Imaging
(1999) J. Magn. Reson. B
(1995)- et al.
J. Magn. Reson.
(1986) - et al.
J. Magn. Reson.
(1988) - et al.
J. Magn. Reson.
(1999) - et al.
Magn. Reson. Imaging
(1998) - et al.
Magn. Reson. Med.
(1987) - et al.
Magnetic Resonance Imaging
(1992)
Magn. Reson. Med.
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SHARQnet – Sophisticated harmonic artifact reduction in quantitative susceptibility mapping using a deep convolutional neural network
2019, Zeitschrift fur Medizinische PhysikCitation Excerpt :One example for satisfying the Laplace equation inside the object of interest, assuming no sources close to boundaries, is sophisticated harmonic artifact reduction for phase data (SHARP) [16]. It solves Poisson's equation utilizing the spherical mean value theorem [18] and requires the definition of a spherical kernel radius and a regularization parameter. The SHARP method was later extended to V-SHARP, utilizing spheres with multiple radii that decrease the size of the kernel towards the brain boundary to reduce artifacts at the edges and thereby extend the usable region of interest [19].
Background field removal using a region adaptive kernel for quantitative susceptibility mapping of human brain
2017, Journal of Magnetic ResonanceCitation Excerpt :The projection onto dipole field (PDF) method [16] exploits dipole field functions to estimate the background field on the assumption that background field and local field are orthogonal in the VOI. In the Laplacian-based methods [17], e.g. the sophisticated harmonic artifact reduction for phase data (SHARP) method [8], the background field is removed using a spherical mean value (SMV) function according to its harmonic features [23,24]. In the original SHARP method, a constant radius was used in the SMV convolution kernel and fairly large erosion has to be used in the brain tissue mask.
Dual-pathway multi-echo sequence for simultaneous frequency and T<inf>2</inf> mapping
2016, Journal of Magnetic ResonanceFoundations of MRI phase imaging and processing for Quantitative Susceptibility Mapping (QSM)
2016, Zeitschrift fur Medizinische Physik2D harmonic filtering of MR phase images in multicenter clinical setting: Toward a magnetic signature of cerebral microbleeds
2015, NeuroImageCitation Excerpt :The remaining border effect at the brain boundary is thus unlikely to cause problems in CMB identification. The more common phase filtering approaches, such as HPF, rely on the assumption that the background field contributions only embed low spatial frequency components (Li and Leigh, 2001; Li et al., 2011; Schweser et al., 2013, 2012a, 2011). Nevertheless, the background field may indeed contain high spatial frequency components and the local field may contain low spatial frequency components, and the resulting internal field map may thus be flawed.