Vicente
Parot1,2, Carlos Sing-Long1,2, Carlos Lizama3,
Sergio Uribe, 2,4, Cristian Tejos1,2, Pablo Irarrazaval1,2
1Department of Electrical Engineering,
Pontificia Universidad Catolica de Chile, Santiago, Chile; 2Biomedical
Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile; 3Department
of Mathematics and Computer Science, Universidad de Santiago de Chile,
Santiago, Chile; 4Department of Radiology, Pontificia Universidad
Catolica de Chile, Santiago, Chile
In
Magnetic Resonance Imaging (MRI) field inhomogeneities produce severe
distortions, especially with long acquisition sequences, e.g. EPI. Shimming
or post-processing strategies are usually applied to correct those
distortions. However, those approaches require additional hardware or long
processing times. We propose an alternative reconstruction method based on
the Fractional Fourier Transform (FrFT) assuming spatially-varying quadratic
fields. We tested our method in phantoms and in vivo acquisitions. Results
demonstrate the ability of our reconstruction scheme to correct the geometric
distortions that appear in standard Fourier Transform reconstructions under
non homogeneous fields.