Increasing efficiency of parallel imaging for 2D multislice acquisitions

@article{Honal2009IncreasingEO,
  title={Increasing efficiency of parallel imaging for 2D multislice acquisitions},
  author={Matthias Honal and Simon Bauer and Ute Ludwig and Jochen Leupold},
  journal={Magnetic Resonance in Medicine},
  year={2009},
  volume={61}
}
Parallel imaging algorithms require precise knowledge about the spatial sensitivity variation of the receiver coils to reconstruct images with full field of view (FOV) from undersampled Fourier encoded data. Sensitivity information must either be given a priori, or estimated from calibration data acquired along with the actual image data. In this study, two approaches are presented, which require very little or no additional data at all for calibration in two‐dimensional multislice acquisitions… 

Cross-sampled GRAPPA for parallel MRI

A cross sampling method is proposed to acquire the ACS lines orthogonal to the reduced lines, which can effectively reduce the aliasing artifacts of GRAPPA when high acceleration is desired.

Improving GRAPPA using cross‐sampled autocalibration data

Reconstruction results from simulations, phantom and in vivo human brain experiments have distinctly demonstrated that the proposed method, named cross‐sampled generalized autocalibrating partially parallel acquisitions, can effectively reduce the aliasing artifacts of conventional generalized Autocalibration signal (ACS) acquisitions when very few ACS lines are acquired, especially at high outer k‐space reduction factors.

Iterative reconstruction method for three- dimensional non-Cartesian parallel MRI

A trust region based step-ratio method that iteratively calculates the penalty coefficient was proposed for the penalty functions and showed higher ROI SNR, two-dataSNR, and lower background noise over conventional method with comparable RMSE, NMI and JE to the reference image at reduced computer resource requirement.

A kernel approach to parallel MRI reconstruction

Experimental results demonstrate that the proposed kernel GRAPPA method can significantly improve the reconstruction quality over the existing methods.

Convex Optimization for 3D Parallel MRI Reconstruction

It is shown that the magnitude of 3D image is constrained in a convex hull and thus can be solved by a two-step convex optimization procedure, resulting in improved reconstructed image with lower meansquared error.

Nonlinear GRAPPA: A kernel approach to parallel MRI reconstruction

Experimental results using phantom and in vivo data demonstrate that the proposed nonlinear GRAPPA method can significantly improve the reconstruction quality overGRAPPA and its state‐of‐the‐art derivatives.

PROMISE: Parallel‐imaging and compressed‐sensing reconstruction of multicontrast imaging using SharablE information

The target of this work is to improve existing CS‐PPI methods for multicontrast imaging, especially for two‐dimensional imaging.

Compensation of breathing motion artifacts for MRI with continuously moving table

A technique for the reduction of breathing‐motion artifacts for MRI with continuously moving table is presented, which reconstructs motion‐consistent volumes from data acquired during free breathing, and is shown to additionally reduce blurring, misregistrations, and signal cancellations in the reconstructed images.

Whole-Body Continuously Moving Table MRI: Principles and Applications

An overview of the different approaches to CMT imaging is given and basic principles of two- and three-dimensional techniques are discussed with emphasis on performance and image-artifact issues.

Magnetic resonance imaging: Review of imaging techniques and overview of liver imaging.

Magnetic resonance imaging (MRI) of the liver is slowly transitioning from a problem solving imaging modality to a first line imaging modality for many diseases of the liver. The well established

References

SHOWING 1-10 OF 18 REFERENCES

Dynamic autocalibrated parallel imaging using temporal GRAPPA (TGRAPPA)

This work demonstrates that a time‐interleaved sampling scheme, in combination with autocalibrated GRAPPA (referred to as TGRAPPA), allows one to easily update the coil weights for the GRAPpa algorithm dynamically, thereby improving the acquisition efficiency.

Autocalibrated coil sensitivity estimation for parallel imaging

Some of the advanced methods to obtain coil sensitivity‐related information, focusing particularly on the class of methods referred to as autocalibrating, are covered.

Generalized autocalibrating partially parallel acquisitions (GRAPPA)

This technique, GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) is an extension of both the PILS and VD‐AUTO‐SMASH reconstruction techniques and provides unaliased images from each component coil prior to image combination.

SENSE: Sensitivity encoding for fast MRI

The problem of image reconstruction from sensitivity encoded data is formulated in a general fashion and solved for arbitrary coil configurations and k‐space sampling patterns and special attention is given to the currently most practical case, namely, sampling a common Cartesian grid with reduced density.

Ultimate intrinsic signal‐to‐noise ratio for parallel MRI: Electromagnetic field considerations

The dependence of the ultimate intrinsic SNR on a variety of experimental conditions is explored and a physically intuitive explanation for the observed behavior is provided based on a comparison between the electromagnetic wavelength and the distance between aliasing points.

Specific coil design for SENSE: A six‐element cardiac array

The implications of SENSE imaging for coil layout by means of simulations and imaging experiments in a phantom and in vivo are studied and new, specific design principles are identified.

Practical approaches to the evaluation of signal‐to‐noise ratio performance with parallel imaging: Application with cardiac imaging and a 32‐channel cardiac coil

Two practical methods for the measurement of signal‐to‐noise‐ratio (SNR) performance in parallel imaging are described and the g‐factor shows qualitative agreement with theoretical predictions from the literature.

Electrodynamics and ultimate SNR in parallel MR imaging

It is concluded that parallel techniques hold particular promise for human MR imaging at very high field because the transition from optimal to deteriorating performance depends on the electrodynamic characteristics of the detected RF fields.

Large field‐of‐view real‐time MRI with a 32‐channel system

A 32‐channel 1.5 T MRI system and 32‐element torso phased arrays were designed and constructed for real‐time interactive MRI and a new method is demonstrated for augmenting parallel image acquisition by independently offsetting the frequency of different array elements (FASSET) to variably shift their FOV.

Measurement of signal‐to‐noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters

To evaluate the validity of different approaches to determine the signal‐to‐noise ratio (SNR) in MRI experiments with multi‐element surface coils, parallel imaging, and different reconstruction filters, a large number of experiments were conducted with single‐element coils and parallel imaging.