Blind retrospective motion correction of MR images

Loktyushin, Alexander; Nickisch, Hannes; Pohmann, R; Schoelkopf, Bernhard

doi:10.1002/mrm.24615

Cited by 78 publications

(77 citation statements)

References 30 publications

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“…Finally, in Section III-E we study the differences in performance with the related approach in [10].…”

Section: A Experimental Designmentioning

confidence: 99%

“…On the one hand, in [13] and [12], a sparse matrix is assumed with its nonzero elements given by the interpolation kernels used to spatially regrid the image after the transformation. On the other hand, in [7] and [10], the transformation is applied in kspace. In this case, translations can be expressed by linear phase weights but, once again, regridding is necessary to implement rotations.…”

Section: B Model Termsmentioning

confidence: 99%

“…Related motion resilient approaches relying on a specific encoding trajectory have been proposed in [8] -using the implicit navigators provided by the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) sampling schemeand [9] (using radial trajectories). A more comprehensive treatment that uses all the acquired data without resorting to explicit or implicit navigators is introduced in [10]. Similarly to our proposal, the authors present a joint reconstruction and motion estimation method, but in their case reconstruction and motion estimation are formulated using distinct functionals, as the former is based on the fidelity to the measured data whereas the latter is based on the minimization of a gradient entropy metric in the image domain.…”

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confidence: 98%

“…The paper is organized as follows: In Section II we present the formulation for joint rigid motion estimation and image reconstruction for parallel multishot MR. In Section III we study both the motion estimation and reconstruction performance of the method with regard to the motion level, encoding trajectories, number of shots, use of prior information, and in relation to the results provided by [10]. In Section IV we explain, assess and illustrate its application in a real scenario, namely, the motion-corrected reconstruction of volumetric MR in neonatal brain imaging.…”

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confidence: 99%

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Sensitivity Encoding for Aligned Multishot Magnetic Resonance Reconstruction

Cordero‐Grande

Teixeira

Hughes

et al. 2016

IEEE Trans. Comput. Imaging

155

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This paper introduces a framework for the reconstruction of magnetic resonance images in the presence of rigid motion. The rationale behind our proposal is to make use of the partial k-space information provided by multiple receiver coils in order to estimate the position of the imaged object throughout the shots that contribute to the image. The estimated motion is incorporated into the reconstruction model in an iterative manner to obtain a motion-free image. The method is parameter-free, does not assume any prior model for the image to be reconstructed, avoids blurred images due to resampling, does not make use of external sensors, and does not require modifications in the acquisition sequence. Validation is performed using synthetically corrupted data to study the limits for full motion-recovered reconstruction in terms of the amount of motion, encoding trajectories, number of shots and availability of prior information, and to compare with the state of the art. Quantitative and visual results of its application to a highly challenging volumetric brain imaging cohort of 207 neonates are also presented, showing the ability of the proposed reconstruction to generally improve the quality of reconstructed images, as evaluated by both sparsity and gradient entropy based metrics.

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“…Finally, in Section III-E we study the differences in performance with the related approach in [10].…”

Section: A Experimental Designmentioning

confidence: 99%

Section: B Model Termsmentioning

confidence: 99%

mentioning

confidence: 98%

mentioning

confidence: 99%

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Sensitivity Encoding for Aligned Multishot Magnetic Resonance Reconstruction

Cordero‐Grande

Teixeira

Hughes

et al. 2016

IEEE Trans. Comput. Imaging

155

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“…34 In addition, robust rotational and out-of-plane motion correction algorithms are still under investigation and can be computationally expensive. 35,36 Note that improved thermometry and shorter procedure times also have the potential to reduce patient motion. Another limitation of this approach is its reliance on standard 2D temperature imaging, with dose calculated from a single slice centered at the focus.…”

Section: Author Manuscriptmentioning

confidence: 99%

Improving thermal dose accuracy in magnetic resonance-guided focused ultrasound surgery: Long-term thermometry using a prior baseline as a reference

Bitton

Webb

Pauly

et al. 2015

J. Magn. Reson. Imaging

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Purpose-To investigate thermal dose volume (TDV) and non-perfused volume (NPV) of magnetic resonance-guided focused ultrasound (MRgFUS) treatments in patients with soft tissue tumors, and describe a method for MR thermal dosimetry using a baseline reference.Materials and Methods-Agreement between TDV and immediate post treatment NPV was evaluated from MRgFUS treatments of five patients with biopsy-proven desmoid tumors. Thermometry data (gradient echo, 3T) were analyzed over the entire course of the treatments to discern temperature errors in the standard approach. The technique searches previously acquired baseline images for a match using 2D normalized cross-correlation and a weighted mean of phase difference images. Thermal dose maps and TDVs were recalculated using the matched baseline and compared to NPV.Results-TDV and NPV showed between 47%-91% disagreement, using the standard immediate baseline method for calculating TDV. Long-term thermometry showed a nonlinear local temperature accrual, where peak additional temperature varied between 4-13°C (mean = 7.8°C) across patients. The prior baseline method could be implemented by finding a previously acquired matching baseline 61% ± 8% (mean ± SD) of the time. We found 7%-42% of the disagreement between TDV and NPV was due to errors in thermometry caused by heat accrual. For all patients, the prior baseline method increased the estimated treatment volume and reduced the discrepancies between TDV and NPV (P = 0.023).Conclusion-This study presents a mismatch between in-treatment and post treatment efficacy measures. The prior baseline approach accounts for local heating and improves the accuracy of thermal dose-predicted volume.Magnetic resonance-guided focused ultrasound (MRgFUS) has been used in clinical trials to ablate soft tissue tumors such as breast tumors, uterine fibroids, and prostate tumors. Some of these trials aimed to show safety and feasibility through partial tumor ablation. [1][2][3][4][5] More recently, patient studies have targeted total tumor volume ablation, including large uterine Total tumor ablation demands a highly accurate method to assess treatment efficacy. MR thermometry-derived thermal dose mapping is the primary method used to assess tumor ablation during an MRgFUS procedure. 9 MR-derived proton resonance frequency shift (PRF) thermometry provides a change in temperature, which is then used to calculate thermal dose; neither absolute temperature nor absolute dose are calculated using these methods. 10 Because these are not absolute measurements, the standard method does not account for local accumulation of heat over the course of a treatment, which can cause errors in thermometry, and thus, errors in the estimated thermal dose delivered to tissue (Fig. 1). 11,12 Underestimation of thermometry and thermal dose may result in unnecessary additional sonications of tissue that has already been ablated through sonication of adjacent areas; these extra sonications provide no benefit, while increasing risks to the patient, such ...

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Motion artifacts in MRI: A complex problem with many partial solutions

Zaitsev

Maclaren

Herbst

2015

Magnetic Resonance Imaging

551

481

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Subject motion during magnetic resonance imaging (MRI) has been problematic since its introduction as a clinical imaging modality. While sensitivity to particle motion or blood flow can be used to provide useful image contrast, bulk motion presents a considerable problem in the majority of clinical applications. It is one of the most frequent sources of artefacts. Over 30 years of research have produced numerous methods to mitigate or correct for motion artefacts, but no single method can be applied in all imaging situations. Instead, a ‘toolbox’ of methods exists, where each tool is suitable for some tasks, but not for others. This article reviews the origins of motion artefacts and presents current mitigation and correction methods. In some imaging situations, the currently available motion correction tools are highly effective; in other cases, appropriate tools still need to be developed. It seems likely that this multifaceted approach will be what eventually solves the motion sensitivity problem in MRI, rather than a single solution that is effective in all situations. This review places a strong emphasis on explaining the physics behind the occurrence of such artefacts, with the aim of aiding artefact detection and mitigation in particular clinical situations.

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Blind retrospective motion correction of MR images

Abstract: The presented technique can be an alternative or a complement to prospective motion correction methods and is able to improve images with strong motion artifacts from standard imaging sequences without requiring additional data.

Cited by 78 publications

References 30 publications

Sensitivity Encoding for Aligned Multishot Magnetic Resonance Reconstruction

Sensitivity Encoding for Aligned Multishot Magnetic Resonance Reconstruction

Improving thermal dose accuracy in magnetic resonance-guided focused ultrasound surgery: Long-term thermometry using a prior baseline as a reference

Motion artifacts in MRI: A complex problem with many partial solutions

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