PROPELLER for motion‐robust imaging of <i>in vivo</i> mouse abdomen at 9.4 T

Teh, Irvin; Golay, Xavier; Larkman, David J.

doi:10.1002/nbm.1535

Cited by 6 publications

(2 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proposed SRR solution would also be suitable on advanced acquisition schemes for high-field abdominal imaging. For instance, using SRR in combination with a self-navigated acquisition scheme like PROPELLER should provide high-resolution 3D T2-weighted contrast at high fields while reducing motion artifacts [24] , [25] .…”

Section: Discussionmentioning

confidence: 99%

Interactive Local Super-Resolution Reconstruction of Whole-Body MRI Mouse Data: A Pilot Study with Applications to Bone and Kidney Metastases

et al. 2014

View full text Add to dashboard Cite

In small animal imaging studies, when the locations of the micro-structures of interest are unknown a priori, there is a simultaneous need for full-body coverage and high resolution. In MRI, additional requirements to image contrast and acquisition time will often make it impossible to acquire such images directly. Recently, a resolution enhancing post-processing technique called super-resolution reconstruction (SRR) has been demonstrated to improve visualization and localization of micro-structures in small animal MRI by combining multiple low-resolution acquisitions. However, when the field-of-view is large relative to the desired voxel size, solving the SRR problem becomes very expensive, in terms of both memory requirements and computation time. In this paper we introduce a novel local approach to SRR that aims to overcome the computational problems and allow researchers to efficiently explore both global and local characteristics in whole-body small animal MRI. The method integrates state-of-the-art image processing techniques from the areas of articulated atlas-based segmentation, planar reformation, and SRR. A proof-of-concept is provided with two case studies involving CT, BLI, and MRI data of bone and kidney tumors in a mouse model. We show that local SRR-MRI is a computationally efficient complementary imaging modality for the precise characterization of tumor metastases, and that the method provides a feasible high-resolution alternative to conventional MRI.

show abstract

Section: Discussionmentioning

confidence: 99%

Interactive Local Super-Resolution Reconstruction of Whole-Body MRI Mouse Data: A Pilot Study with Applications to Bone and Kidney Metastases

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Alternative acquisition strategies such as radial, spiral and, in the case of the RARE scan mode, PROPELLER, are able to reduce the effect of physiological motions by oversampling the centre of k-space in a manner that essentially performs low spatial frequency signal averaging, albeit at the expense of scan time [[15], [16], [17]]. The reduced sensitivity of PROPELLER to respiration motion has enabled the ADC of mouse liver to be determined with an approximately three-fold reduction in standard deviation when compared to both ungated and respiration triggered RARE scan modes [17]. Although a good degree of motion correction is possible, the destructive interference between echoes of the RARE CPMG echo train that is caused by a loss of phase coherence cannot be recovered.…”

Section: Introductionmentioning

confidence: 99%

Reduced respiratory motion artefact in constant TR multi-slice MRI of the mouse

Kinchesh

Allen

Gilchrist

et al. 2019

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Purpose Multi-slice scanning in the abdomen and thorax of small animals is compromised by the effects of respiration unless imaging and respiration are synchronised. To avoid the signal modulations that result from respiration motion and a variable TR, blocks of fully relaxed slices are typically acquired during inter-breath periods, at the cost of scan efficiency. This paper reports a conceptually simple yet effective prospective gating acquisition mode for multi-slice scanning in free breathing small animals at any fixed TR of choice with reduced sensitivity to respiratory motion. Methods Multi-slice scan modes have been implemented in which each slice has its own specific projection or phase encode loop index counter. When a breath is registered RF pulses continue to be applied but data are not acquired, and the corresponding counters remain fixed so that the data are acquired one TR later, providing it coincides with an inter-breath period. The approach is refined to reacquire the slice data that are acquired immediately before each breath is detected. Only the data with reduced motion artefact are used in image reconstruction. The efficacy of the method is demonstrated in the RARE scan mode which is well known to be particularly useful for tumour visualization. Results Validation in mice with RARE demonstrates improved stability with respect to ungated scanning where signal averaging is often used to reduce artefacts. SNR enhancement maps demonstrate the improved efficiency of the proposed method that is equivalent to at least a 2.5 fold reduction in scan time with respect to ungated signal averaging. A steady-state magnetisation transfer contrast prepared gradient echo implementation is observed to highlight tumour structure. Supplementary simulations demonstrate that only small variations in respiration rate are required to enable efficient sampling with the proposed method. Conclusions The proposed prospective gating acquisition scheme enables efficient multi-slice scanning in small animals at the optimum TR with reduced sensitivity to respiratory motion. The method is compatible with a wide range of complementary methods including non-Cartesian scan modes, partially parallel imaging, and compressed sensing. In particular, the proposed scheme reduces the need for continual close monitoring to effect operator intervention in response to respiratory rate changes, which is both difficult to maintain and precludes high throughput.

show abstract