Publications by authors named "Jonathan Scharff Nielsen"
Article Synopsis
- Cellular senescence contributes to age-related diseases and tauopathies, making it a target for potential therapies.
- This study explored the effectiveness of a senolytic therapy (dasatinib and quercetin) on a tauopathy mouse model, revealing improvements in brain health and cognitive function.
- Non-invasive MRI techniques were used to monitor brain changes, showing that the treatment preserved blood-brain barrier integrity and reduced brain atrophy, suggesting that this therapy could be promising for clinical trials in tauopathy disorders.
Metal artifact reduction (MAR) algorithms reduce the errors caused by metal implants in x-ray computed tomography (CT) images and are an important part of error management in radiotherapy. A promising MAR approach is to leverage the information in magnetic resonance (MR) images that can be acquired for organ or tumor delineation. This is however complicated by the ambiguous relationship between CT values and conventional-sequence MR intensities as well as potential co-registration issues.
View Article and Find Full Text PDFPurpose: We investigated the impact on computed tomography (CT) image quality and photon, electron, and proton head-and-neck (H&N) radiotherapy (RT) dose calculations of three CT metal artifact reduction (MAR) approaches: A CT-based algorithm (oMAR Philips Healthcare), manual water override, and our recently presented, Magnetic Resonance (MR)-based kerMAR algorithm. We considered the following three hypotheses: I: Manual water override improves MAR over the CT- and MR-based alternatives; II: The automatic algorithms (oMAR and kerMAR) improve MAR over the uncorrected CT; III: kerMAR improves MAR over oMAR.
Methods: We included a veal shank phantom with/without six metal inserts and nine H&N RT patients with dental implants.
Article Synopsis
- Molecular diffusion using diffusion weighted MRI (DWI) helps investigate tissue microstructure but interpreting the data is complicated due to the variety of tissue shapes and orientations in the imaging voxel.
- Double diffusion encoding (DDE) can improve analysis by measuring how diffusivity varies in different directions, potentially isolating effects of compartment shape.
- The authors introduce a new method combining DDE with oscillating gradient spin echo (OGSE) to analyze post mortem brain tissue, successfully retrieving accurate diffusion data from simulations of complex tissue geometries.*