Regularization of parallel MRI reconstruction using in vivo coil sensitivities

Qi Duan, Ricardo Otazo, Jian Xu, Daniel K. Sodickson

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Parallel MRI can achieve increased spatiotemporal resolution in MRI by simultaneously sampling reduced k-space datawith multiple receiver coils. One requirement that different parallel MRI techniques have in common is the need to determine spatial sensitivity information for the coil array. This is often done by smoothing the raw sensitivities obtained from low-resolution calibration images, for example via polynomial fitting. However, this sensitivity post-processing can be both time-consuming and error-prone. Another important factor in Parallel MRI is noise amplification in the reconstruction, which is due to non-unity transformations in the image reconstruction associated with spatially correlated coil sensitivity profiles. Generally, regularization approaches, such as Tikhonov and SVD-based methods, are applied to reduce SNR loss, at the price of introducing residual aliasing. In this work, we present a regularization approach using in vivo coil sensitivities in parallel MRI to overcome these potential errors into the reconstruction. The mathematical background of the proposed method is explained, and the technique is demonstrated with phantom images. The effectiveness of the proposed method is then illustrated clinically in a whole-heart 3D cardiac MR acquisition within a single breath-hold. The proposed method can not only overcome the sensitivity calibration problem, but also suppress a substantial portion of reconstruction-related noise without noticeable introduction of residual aliasing artifacts.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2009
Subtitle of host publicationPhysics of Medical Imaging
StatePublished - 2009
EventMedical Imaging 2009: Physics of Medical Imaging - Lake Buena Vista, FL, United States
Duration: Feb 9 2009Feb 12 2009

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceMedical Imaging 2009: Physics of Medical Imaging
Country/TerritoryUnited States
CityLake Buena Vista, FL


  • Artifact correction
  • Denoising
  • In vivo coil sensitivities
  • Noise reduction
  • Parallel MRI
  • SEN Sitivity encoding (SENSE)
  • g-factor
  • regularization

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


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