Abstract #2939

Reconstruction Method for Non-Homogeneous Magnetic Fields Using the Fractional Fourier Transform

Vicente Parot^1,2, Carlos Sing-Long^1,2, Carlos Lizama³, Sergio Uribe,^2,4, Cristian Tejos^1,2, Pablo Irarrazaval^1,2

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.