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Researchers increasingly engage in adopting open science practices in the field of research syntheses, such as preregistration. Preregistration is a central open science practice in empirical research to enhance transparency in the research process and it gains steady adoption in the context of conducting research synthesis. From an interdisciplinary perspective, frameworks and particularly templates are lacking which support researchers preparing a preregistration. To this end, we introduce preregRS, a template to guide researchers across disciplines through the process of preregistering research syntheses. We utilized an R Markdown template file to provide a framework that structures the process of preparing a preregistration. Researchers can write up the preregistration using the template file similar to filling out a form, with the template providing additional hints and further information for the decisions along the framework. We integrated the R Markdown template in an R package for easy installation and use, but also provide a browser-based option for users granting low-barrier access. PreregRS constitutes a first step to facilitate and support preregistration with research syntheses for all disciplines. It further adds to establishing open science practices in conducting research syntheses.

PurposeStructure-guided total variation is a recently introduced prior that allows reconstruction of images using knowledge of the location and orientation of edges in a reference image. In this work, we demonstrate the advantages of a variant of structure-guided total variation known as directional total variation (DTV), over traditional total variation (TV), in the context of compressed-sensing reconstruction and super-resolution.MethodsWe compared TV and DTV in retrospectively undersampled ex vivo diffusion tensor imaging and diffusion spectrum imaging data from healthy, sham, and hypertrophic rat hearts.ResultsIn compressed sensing at an undersampling factor of 8, the RMS error of mean diffusivity and fractional anisotropy relative to the fully sampled ground truth were 44% and 20% lower in DTV compared with TV. In super-resolution, these values were 29% and 14%, respectively. Similarly, we observed improvements in helix angle, transverse angle, sheetlet elevation, and sheetlet azimuth. The RMS error of the diffusion kurtosis in the undersampled data relative to the ground truth was uniformly lower (22% on average) with DTV compared to TV.ConclusionAcquiring one fully sampled non-diffusion-weighted image and 10 diffusion-weighted images at 8× undersampling would result in an 80% net reduction in data needed. We demonstrate efficacy of the DTV algorithm over TV in reducing data sampling requirements, which can be translated into higher apparent resolution and potentially shorter scan times. This method would be equally applicable in diffusion MRI applications outside the heart.

Quantum dots (QDs) are semiconducting inorganic nanocrystals, that have garnered interest in biological and medical spheres due, to their potential benefits in biomedical imaging and drug-delivery systems. Indium phosphide QDs shelled with zinc sulphide (InP/ZnS) are viewed as more biocompatible than previous heavy metal based QDs. However, little is known about how InP/ZnS QDs affect a key blood cell, the platelet. Understanding how platelets interact with QDs is critical as unwanted activation can lead to pathological thrombus formation. Herein, we demonstrate PEGylation of InP/ZnS QDs coated with lipoic acid (QD-LA) or coated with penicillamine (QD-Pen) surface ligands induced markedly less platelet aggregation, platelet–QD interactions, integrin activation, alpha granule secretion and restored platelet spreading in washed platelets in comparison to their non-PEGylated counterparts. Furthermore, in whole blood, PEGylation of QDs reduced the number of QDs in the thrombus, thereby helping to minimise the chance of dysfunctional thrombus formation. Overall, we show that QD PEGylation is important to help prevent QD mediated platelet activation. In combination with the most biocompatible coating, PEGylation markedly reduced platelet activation, widening the concentrations at which QDs were viable for development as potential drug delivery or imaging agents. [ABSTRACT FROM AUTHOR]

This study aimed to examine different trajectory correction methods for spiral imaging on a preclinical scanner with high‐performance gradients with respect to image quality in a phantom and in vivo. The gold standard method of measuring the trajectories in a separate experiment is compared to an isotropic delay‐correction, a correction using the gradient system transfer function (GSTF), and a combination of the two. Three different spiral trajectories, with 96, 16, and three interleaves, are considered. The best image quality is consistently achieved when determining the trajectory in a separate phantom measurement. However, especially for the spiral with 96 interleaves, the other correction methods lead to almost comparable results. Remaining imperfections in the corrected gradient waveforms and trajectories are attributed to asymmetrically occurring undulations in the actual, generated gradients, suggesting that the underlying assumption of linearity is violated. In conclusion, images of sufficient quality can be acquired on preclinical small‐animal scanners using spiral k‐space trajectories without the need to carry out separate trajectory measurements each time. Depending on the trajectory, a simple isotropic delay‐correction or a GSTF‐based correction can provide images of similar quality. [ABSTRACT FROM AUTHOR]

Purpose: This work reports for the first time on the implementation and application of cardiac diffusion‐weighted MRI on a Connectom MR scanner with a maximum gradient strength of 300 mT/m. It evaluates the benefits of the increased gradient performance for the investigation of the myocardial microstructure. Methods: Cardiac diffusion‐weighted imaging (DWI) experiments were performed on 10 healthy volunteers using a spin‐echo sequence with up to second‐ and third‐order motion compensation (M2$$ {M}_2 $$ and M3$$ {M}_3 $$) and b=100, 450$$ b=100,450 $$, and 1000 s/mm2$$ \mathrm{s}/\mathrm{m}{\mathrm{m}}^2 $$ (twice the bmax$$ {b}_{\mathrm{max}} $$ commonly used on clinical scanners). Mean diffusivity (MD), fractional anisotropy (FA), helix angle (HA), and secondary eigenvector angle (E2A) were calculated for b = [100, 450] s/mm2$$ \mathrm{s}/\mathrm{m}{\mathrm{m}}^2 $$ and b = [100, 1000] s/mm2$$ \mathrm{s}/\mathrm{m}{\mathrm{m}}^2 $$ for both M2$$ {M}_2 $$ and M3$$ {M}_3 $$. Results: The MD values with M3$$ {M}_3 $$ are slightly higher than with M2$$ {M}_2 $$ with ΔMD=0.05±0.05[×10−3mm2/s](p=4e−5)$$ \Delta \mathrm{MD}=0.05\pm 0.05\kern0.3em \left[\times 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=4e-5\right) $$ for bmax=450s/mm2$$ {b}_{\mathrm{max}}=450\kern0.3em \mathrm{s}/{\mathrm{mm}}^2 $$ and ΔMD=0.03±0.03[×10−3mm2/s](p=4e−4)$$ \Delta \mathrm{MD}=0.03\pm 0.03\kern0.3em \left[\times \kern0.3em 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=4e-4\right) $$ for bmax=1000s/mm2$$ {b}_{\mathrm{max}}=1000\kern0.3em \mathrm{s}/{\mathrm{mm}}^2 $$. A reduction in MD is observed by increasing the bmax$$ {b}_{\mathrm{max}} $$ from 450 to 1000 s/mm2$$ \mathrm{s}/{\mathrm{mm}}^2 $$ (ΔMD=0.06±0.04[×10−3mm2/s](p=1.6e−9)$$ \Delta \mathrm{MD}=0.06\pm 0.04\kern0.3em \left[\times \kern0.3em 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=1.6e-9\right) $$ for M2$$ {M}_2 $$ and ΔMD=0.08±0.05[×10−3mm2/s](p=1e−9)$$ \Delta \mathrm{MD}=0.08\pm 0.05\kern0.3em \left[\times \kern0.3em 1{0}^{-3}\kern0.3em {\mathrm{mm}}^2/\mathrm{s}\right]\kern0.3em \left(p=1e-9\right) $$ for M3$$ {M}_3 $$). The difference between FA, E2A, and HA was not significant in different schemes (p>0.05$$ p>0.05 $$). Conclusion: This work demonstrates cardiac DWI in vivo with higher b‐value and higher order of motion compensated diffusion gradient waveforms than is commonly used. Increasing the motion compensation order from M2$$ {M}_2 $$ to M3$$ {M}_3 $$ and the maximum b‐value from 450 to 1000 s/mm2$$ \mathrm{s}/{\mathrm{mm}}^2 $$ affected the MD values but FA and the angular metrics (HA and E2A) remained unchanged. Our work paves the way for cardiac DWI on the next‐generation MR scanners with high‐performance gradient systems. [ABSTRACT FROM AUTHOR]