Browsing by author "Wetscherek, Andreas"
Now showing items 1-20 of 27
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Accelerating 4D image reconstruction for magnetic resonance-guided radiotherapy.
Lecoeur, B; Barbone, M; Gough, J; Oelfke, U; Luk, W; et al. (ELSEVIER, 2023-07-01)BACKGROUND AND PURPOSE: Physiological motion impacts the dose delivered to tumours and vital organs in external beam radiotherapy and particularly in particle therapy. The excellent soft-tissue demarcation of 4D magnetic ... -
An optimized b-value distribution for triexponential intravoxel incoherent motion (IVIM) in the liver.
Riexinger, A; Martin, J; Wetscherek, A; Kuder, TA; Uder, M; et al. (WILEY, 2021-04-01)PURPOSE: To find an optimized b-value distribution for reproducible triexponential intravoxel incoherent motion (IVIM) exams in the liver. METHODS: A numeric optimization of b-value distributions was performed using the ... -
Audit feasibility for geometric distortion in magnetic resonance imaging for radiotherapy.
Alzahrani, M; Broadbent, DA; Chuter, R; Al-Qaisieh, B; Jackson, S; et al. (ELSEVIER, 2020-07-01)BACKGROUND AND PURPOSE: Magnetic Resonance Imaging (MRI) is increasingly being used in radiotherapy (RT). However, geometric distortions are a known challenge of using MRI in RT. The aim of this study was to demonstrate ... -
Automatic reconstruction of the delivered dose of the day using MR-linac treatment log files and online MR imaging.
Menten, MJ; Mohajer, JK; Nilawar, R; Bertholet, J; Dunlop, A; et al. (ELSEVIER IRELAND LTD, 2020-01-10)BACKGROUND AND PURPOSE: Anatomical changes during external beam radiotherapy prevent the accurate delivery of the intended dose distribution. Resolving the delivered dose, which is currently unknown, is crucial to link ... -
Characterization of the diffusion coefficient of blood.
Funck, C; Laun, FB; Wetscherek, A (WILEY, 2018-05-01)PURPOSE: To characterize the diffusion coefficient of human blood for accurate results in intravoxel incoherent motion imaging. METHODS: Diffusion-weighted MRI of blood samples from 10 healthy volunteers was acquired with ... -
Daily Intravoxel Incoherent Motion (IVIM) In Prostate Cancer Patients During MR-Guided Radiotherapy-A Multicenter Study.
Kooreman, ES; van Houdt, PJ; Keesman, R; van Pelt, VWJ; Nowee, ME; et al. (FRONTIERS MEDIA SA, 2021-08-13)PURPOSE: Daily quantitative MR imaging during radiotherapy of cancer patients has become feasible with MRI systems integrated with linear accelerators (MR-linacs). Quantitative images could be used for treatment response ... -
Delayed contrast dynamics as marker of regional impairment in pulmonary fibrosis using 5D MRI - a pilot study.
Buzan, MT; Wetscherek, A; Rank, CM; Kreuter, M; Heussel, CP; et al. (BRITISH INST RADIOLOGY, 2020-09-01)OBJECTIVE: To analyse delayed contrast dynamics of fibrotic lesions in interstitial lung disease (ILD) using five dimensional (5D) MRI and to correlate contrast dynamics with disease severity. METHODS: 20 patients (mean ... -
Echo time dependence of biexponential and triexponential intravoxel incoherent motion parameters in the liver.
Führes, T; Riexinger, AJ; Loh, M; Martin, J; Wetscherek, A; et al. (WILEY, 2021-08-28)PURPOSE: Intravoxel incoherent motion (IVIM) studies are performed with different acquisition protocols. Comparing them requires knowledge of echo time (TE) dependencies. The TE-dependence of the biexponential perfusion ... -
Efficient Online 4D Magnetic Resonance Imaging
Barbone, M; Wetscherek, A; Yung, T; Oelfke, U; Luk, W; et al. (IEEE COMPUTER SOC, 2021-01-01) -
Evaluation of MRI-derived surrogate signals to model respiratory motion.
Tran, EH; Eiben, B; Wetscherek, A; Oelfke, U; Meedt, G; et al. (IOP PUBLISHING LTD, 2020-07-01)An MR-Linac can provide motion information of tumour and organs-at-risk before, during, and after beam delivery. However, MR imaging cannot provide real-time high-quality volumetric images which capture breath-to-breath ... -
Joint radial trajectory correction for accelerated T2 * mapping on an MR-Linac.
Bano, W; Holmes, W; Goodburn, R; Golbabaee, M; Gupta, A; et al. (WILEY, 2023-05-27)BACKGROUND: T2 * mapping can characterize tumor hypoxia, which may be associated with resistance to therapy. Acquiring T2 * maps during MR-guided radiotherapy could inform treatment adaptation by, for example, escalating ... -
Longitudinal Stability of MRI QA up to Two Years on Eight Clinical 1.5 T MR-Linacs
Wetscherek, A; van der Bijl, E; van Lier, ALH; Chick, J; Jackson, S; et al. (FRONTIERS MEDIA SA, 2022-06-13)<jats:p>MR-guided radiotherapy on hybrid MR-Linacs exploits the excellent soft-tissue contrast of MRI to deliver daily adaptive precision radiotherapy. Geometric fidelity and long-term stability of MRI components are ... -
MRI commissioning of 1.5T MR-linac systems - a multi-institutional study.
Tijssen, RHN; Philippens, MEP; Paulson, ES; Glitzner, M; Chugh, B; et al. (ELSEVIER IRELAND LTD, 2019-03-01)BACKGROUND: Magnetic Resonance linear accelerator (MR-linac) systems represent a new type of technology that allows for online MR-guidance for high precision radiotherapy (RT). Currently, the first MR-linac installations ... -
MRI-guided lung SBRT: Present and future developments.
Menten, MJ; Wetscherek, A; Fast, MF (ELSEVIER SCI LTD, 2017-12-01)Stereotactic body radiotherapy (SBRT) is rapidly becoming an alternative to surgery for the treatment of early-stage non-small cell lung cancer patients. Lung SBRT is administered in a hypo-fractionated, conformal manner, ... -
Optimal acquisition scheme for flow-compensated intravoxel incoherent motion diffusion-weighted imaging in the abdomen: An accurate and precise clinically feasible protocol.
Gurney-Champion, OJ; Rauh, SS; Harrington, K; Oelfke, U; Laun, FB; et al. (WILEY, 2020-03-01)PURPOSE: Flow-compensated (FC) diffusion-weighted MRI (DWI) for intravoxel-incoherent motion (IVIM) modeling allows for a more detailed description of tissue microvasculature than conventional IVIM. The long acquisition ... -
Principal component analysis fosr fast and model-free denoising of multi b-value diffusion-weighted MR images.
Gurney-Champion, OJ; Collins, DJ; Wetscherek, A; Rata, M; Klaassen, R; et al. (IOP PUBLISHING LTD, 2019-04-09)Despite the utility of tumour characterisation using quantitative parameter maps from multi-b-value diffusion-weighted MRI (DWI), clinicians often prefer the use of the image with highest diffusion-weighting (b-value), for ... -
Quantitative analysis of diffusion weighted imaging in rectal cancer during radiotherapy using a magnetic resonance imaging integrated linear accelerator.
Ingle, M; Blackledge, M; White, I; Wetscherek, A; Lalondrelle, S; et al. (ELSEVIER, 2022-07-01)BACKGROUND AND PURPOSE: Magnetic resonance imaging integrated linear accelerator (MR-Linac) platforms enable acquisition of diffusion weighted imaging (DWI) during treatment providing potential information about treatment ... -
Rapid 4D-MRI reconstruction using a deep radial convolutional neural network: Dracula.
Freedman, JN; Gurney-Champion, OJ; Nill, S; Shiarli, A-M; Bainbridge, HE; et al. (ELSEVIER IRELAND LTD, 2021-06-01)BACKGROUND AND PURPOSE: 4D and midposition MRI could inform plan adaptation in lung and abdominal MR-guided radiotherapy. We present deep learning-based solutions to overcome long 4D-MRI reconstruction times while maintaining ... -
Realizing the potential of magnetic resonance image guided radiotherapy in gynaecological and rectal cancer.
White, IM; Scurr, E; Wetscherek, A; Brown, G; Sohaib, A; et al. (BRITISH INST RADIOLOGY, 2019-05-14)CT-based radiotherapy workflow is limited by poor soft tissue definition in the pelvis and reliance on rigid registration methods. Current image-guided radiotherapy and adaptive radiotherapy models therefore have limited ... -
Recommendations for improved reproducibility of ADC derivation on behalf of the Elekta MRI-linac consortium image analysis working group.
Bisgaard, ALH; Keesman, R; van Lier, ALHMW; Coolens, C; van Houdt, PJ; et al. (ELSEVIER IRELAND LTD, 2023-09-01)BACKGROUND AND PURPOSE: The apparent diffusion coefficient (ADC), a potential imaging biomarker for radiotherapy response, needs to be reproducible before translation into clinical use. The aim of this study was to evaluate ...