Meeting Banner
Abstract #2563

Correcting bSSFP Distortion Near Metals with Geometric Solution Phase

Michael Nicholas Hoff1, Qing-San Xiang1, 2

1Physics, University of British Columbia, Vancouver, BC, Canada; 2Radiology, University of British Columbia, Vancouver, BC, Canada

Balanced steady state free precession imaging can suffer from geometric distortion near metals. The geometric solution (GS) for banding correction has phase which maps the local field inhomogeneity; here this phase is unwrapped and used to remap distorted signal in the GS magnitude image. This distortion correction did not require a phase reference due to the insignificance of phase error relative to the off-resonant phase accumulation near the metal, and the unwrapping algorithm proved robust in all signal regions. The advantage of this correction is that it does not require excess scan time beyond that needed to compute the GS.

Keywords

accumulates accumulation accuracy achieved added additional allowed applied arrows artifacts audience axes balanced banding bands bandwidth benefit benefits beyond binary building cage chromium clinicians cobalt complex computation computed consisting continuity continuously coordinate correct corrected correcting correction cycling delimits described dimensions displacement display distorted distortion emphasize employing encasing encoding error essentially exact excessive exhibits expanded expanding extra feasible field fields final flow free frequency generated geometric gradients green guided implementation indicate indicates inhomogeneity inhomogeneous insignificant interpolation labeling local loss magnitude makes matrix mesh metals minimal minimized molybdenum naturally nature near needed network note observably occur phantom physics pixel pixels polyethylene positioning precession problems processing proposed prosthesis radiology rapidly recently regardless relatively remap remapping remote remove removed repetition require requirement requirements requiring researchers resonant respective scanning secured seem short slice smoothing solution square stabilized steady strong suffers surgery synergistic target therapy undesirable unnecessary unwrapped unwrapping variable varies various varying vertical water white wrapped