Medical physics is a branch of applied physics concerning the application of physics to medicine. It generally concerns physics as applied to medical imaging and radiotherapy, although a medical physicist may also work in many other areas of healthcare. A medical physics department may be based in either a hospital or a university and its work is likely to include research, technical development and clinical healthcare.

Medical imaging

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• Diagnostic radiology, including x-rays, fluoroscopy, mammography, Dual energy X-ray absorptiometry, angiography and Computed tomography
• Ultrasound, including intravascular ultrasound
• Non-ionising radiation (Lasers, Ultraviolet etc.)
• Nuclear medicine, including SPECT and positron emission tomography (PET)
• Magnetic resonance imaging (MRI), including functional magnetic resonance imaging (fMRI) and other methods for functional neuroimaging of the brain.
  • For example, nuclear magnetic resonance (often referred to as magnetic resonance imaging to avoid the common concerns about radiation), uses the phenomenon of nuclear resonance to image the human body.
• Magnetoencephalography
• Electrical impedance tomography
• Diffuse optical imaging
• Optical coherence tomography
• Terahertz radiation

Treatment of disease

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• Defibrillation
• High intensity focussed ultrasound, including lithotripsy
• Interventional radiology
• Non-ionising radiation Lasers, Ultraviolet etc. including photodynamic therapy and LASIK
• Nuclear medicine, including unsealed source radiotherapy
• Photomedicine, the use of light to treat and diagnose disease
• Radiotherapy
• Sealed source radiotherapy

More on [ Medical physics ]

Magnetic Resonance Materials in Physics, Biology and Medicine

Diffusion simulation-based fiber tracking using time-of-arrival maps: a comparison with standard methods
Sat, 30 Jan 2010 18:13:13 -0000
Abstract Object  We propose a new tracking method based on time-of-arrival (TOA) maps derived from simulated diffusion processes. Materials and methods  The proposed diffusion simulation-based tracking consists of three steps that are successively evaluated on small overlapping sub-regions in a diffusion tensor field. First, the diffusion process is simulated for several time steps. Second, a TOA map is created to store simulation results for the individual time steps that are required for the tract reconstruction. Third, the fiber pathway is reconstructed on the TOA map and concatenated between neighboring sub-regions. This new approach is compared with probabilistic and streamline tracking. All methods are applied to synthetic phantom data for an easier evaluation of their fiber reconstruction quality. Results  The comparison of the tracking results did show severe problems for the streamline approach in the reconstruction of crossing fibers, for example. The probabilistic method was able to resolve the crossing, but could not handle strong curvature. The new diffusion simulation-based tracking could reconstruct all problematic fiber constellations. Conclusion  The proposed diffusion simulation-based tracking method used the whole tensor information of a neighborhood of voxels and is, therefore, able to handle problematic tracking situations better than established methods. Content Type Journal ArticleCategory Research ArticleDOI 10.1007/s10334-009-0195-xAuthors Sarah C. Mang, University Hospital Section Experimental MR, Department of Neuroradiology Tuebingen GermanyDmitriy Logashenko, Steinbeis-Forschungszentrum 936 Oelbronn-Duerrn GermanyDaniel Gembris, University Mannheim Institute for Computational Medicine Mannheim GermanyGabriel Wittum, Goethe University Goethe Center for Scientific Computing (G-CSC), Simulation and Modelling Frankfurt GermanyWolfgang Grodd, University Hospital Section Experimental MR, Department of Neuroradiology Tuebingen GermanyUwe Klose, University Hospital Section Experimental MR, Department of Neuroradiology Tuebingen Germany Journal Magnetic Resonance Materials in Physics, Biology and MedicineOnline ISSN 1352-8661Print ISSN 0968-5243
Present and future of simultaneous EEG-fMRI
Mon, 25 Jan 2010 16:59:15 -0000
Abstract  The brain’s activity can be measured in numerous complementary ways, including electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). The simultaneous acquisition of EEG and fMRI was originally developed to make the localization of the generators of often subtle pathological activity commonly observed in EEG recordings of patients with epilepsy more sensitive and spatially accurate by mapping their hemodynamic correlates. Now, the value of the information provided by simultaneous EEG-fMRI is being evaluated in a clinical context, while in parallel, more sophisticated data analysis techniques, e.g. with electrical source imaging or dynamic causal modeling, have begun to be applied to increase the technique’s sensitivity and allow the study of brain network structure. Beyond its clinically oriented application in epilepsy, simultaneous EEG-fMRI recording has now gained interest as a tool for basic and systems human neuroscience, e.g. the study of neuro-vascular coupling and cognitive studies. In this review, we give an overview over the current use of simultaneous EEG-fMRI, its applications to the study of epilepsy as well as human cognition and systems neuroscience and ongoing and anticipated methodological developments. Content Type Journal ArticleCategory Review ArticleDOI 10.1007/s10334-009-0196-9Authors Karin Rosenkranz, UCL Institute of Neurology Department of Clinical and Experimental Epilepsy 33 Queen Square London WC1N 3BG UKLouis Lemieux, UCL Institute of Neurology Department of Clinical and Experimental Epilepsy 33 Queen Square London WC1N 3BG UK Journal Magnetic Resonance Materials in Physics, Biology and MedicineOnline ISSN 1352-8661Print ISSN 0968-5243
Detection of vascular alterations by in vivo magnetic resonance angiography and histology in APP/PS1 mouse model of Alzheimer’s disease
Tue, 12 Jan 2010 06:45:06 -0000
Abstract Object  The brain of patients with Alzheimer’s disease (AD) is characterized by the presence of amyloid plaques and neurofibrillary tangles. Vascular alterations such as amyloid angiopathy are also commonly reported in patients with AD and participate in mechanisms involved in disease onset and progression. Transgenic mouse models of AD have been engineered to evaluate the pathophysiology and new treatments of the disease. Our study evaluated vascular alterations in APPSweLon/PS1M146L mouse model of AD. Materials and methods  Histological analysis and in vivo magnetic resonance angiography protocols based on time of flight (TOF) and contrast-enhanced (CE) angiography were applied to evaluate cerebrovascular alterations. Results  Histological analysis showed that cerebrovascular amyloid deposition starts by the same time as extracellular amyloid plaques. However, unlike plaques deposition, severity of cerebrovascular alterations is stabilized in older animals. Alteration of the middle cerebral artery was detected in old APPSweLon/PS1M146L mice with respect to adult ones by evaluating the severity of vessel voids and the reduction of vessel length on TOF- and CE-angiograms. Age-related alterations in control PS1 mice were only detected as a reduced vessel length on CE-angiograms. Conclusion  These results show that macroscopic vascular abnormalities are part of the pathological alterations developed by APPSweLon/PS1M146L mouse models of AD. Content Type Journal ArticleCategory Research ArticleDOI 10.1007/s10334-009-0194-yAuthors Nadine El Tannir El Tayara, Institut Curie, Centre de Recherche Orsay FranceBenoît Delatour, CNRS UMR 8620, Laboratoire NAMC Orsay FranceAndreas Volk, Institut Curie, Centre de Recherche Orsay FranceMarc Dhenain, Institut Curie, Centre de Recherche Orsay France Journal Magnetic Resonance Materials in Physics, Biology and MedicineOnline ISSN 1352-8661Print ISSN 0968-5243 Journal Volume Volume 23 Journal Issue Volume 23, Number 1 / February, 2010
Grid-free interactive and automated data processing for MR chemical shift imaging data
Tue, 05 Jan 2010 17:00:06 -0000
Abstract Purpose  Today’s available chemical shift imaging (CSI) analysis tools are based on Fourier transform of the entire data set prior to interactive display. This strategy is associated with limitations particularly when arbitrary voxel positions within a 3D spatial volume are needed by the user. In this work, we propose and demonstrate a processing-resource-efficient alternative strategy for both interactive and automated CSI data processing up to three spatial dimensions. Methods  This approach uses real-time voxel-shift by first-order phase manipulation as a basis and therefore allows grid-free voxel positioning within the 3D volume. The corresponding spectrum is extracted from the 4D data (3D spatial/1D spectral) at each time a voxel position is selected. The spatial response function and hence the exact voxel size and shape are calculated in parallel including the same processing parameters. Using this mechanism sequentially along with AMARES time-domain modeling, we also implemented automated quantitative and B 0-insensitive metabolite mapping. Results  Metabolite maps of N-acetyl aspartate, choline and creatine were generated using 1H-CSI data from the brain of healthy volunteers and patients with tumor and epilepsy. 31P-3D-CSI of the heart of a healthy volunteer is also shown. Conclusion  The calculated metabolite maps demonstrate good stability and accuracy of the algorithm in all situations tested. The suggested algorithm constitutes therefore an attractive alternative to existing CSI processing strategies. Content Type Journal ArticleCategory Research ArticleDOI 10.1007/s10334-009-0186-yAuthors Yann Le Fur, Université de la Méditerranée Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS No 6612, Faculté de Médecine de Marseille 27 Bd Jean Moulin 13385 Marseille Cedex 5 FranceFrançois Nicoli, Université de la Méditerranée Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS No 6612, Faculté de Médecine de Marseille 27 Bd Jean Moulin 13385 Marseille Cedex 5 FranceMaxime Guye, Université de la Méditerranée Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS No 6612, Faculté de Médecine de Marseille 27 Bd Jean Moulin 13385 Marseille Cedex 5 FranceSylviane Confort-Gouny, Université de la Méditerranée Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS No 6612, Faculté de Médecine de Marseille 27 Bd Jean Moulin 13385 Marseille Cedex 5 FrancePatrick J. Cozzone, Université de la Méditerranée Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS No 6612, Faculté de Médecine de Marseille 27 Bd Jean Moulin 13385 Marseille Cedex 5 FranceFrank Kober, Université de la Méditerranée Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS No 6612, Faculté de Médecine de Marseille 27 Bd Jean Moulin 13385 Marseille Cedex 5 France Journal Magnetic Resonance Materials in Physics, Biology and MedicineOnline ISSN 1352-8661Print ISSN 0968-5243 Journal Volume Volume 23 Journal Issue Volume 23, Number 1 / February, 2010
Small field of view imaging using wavelet encoding with 2 dimensional RF pulses and gradient echo: phantom results
Sat, 19 Dec 2009 06:50:22 -0000
Abstract Object  The objective of this work is to propose an imaging sequence based upon the wavelet encoding approach to provide MRI images free from folding artifacts, in the small field of view (FOV) regime, such as dynamic magnetic resonance imaging (MRI) studies. Materials and methods  The method consists of using a 2D spatially selective RF excitation pulse inserted into a gradient- echo pulse sequence to excite spins within a determined plane where wavelet encoding is achieved in one direction and slice selection is performed in the second direction. Wavelet encoding allows for spatially localized excitation and consequently restricts the spins excited within a reduced FOV. It consists of varying, according to a predetermined scheme, the width and position of the profile of the so-called fast RF pulse of the 2D RF excitation pulse, to obey wavelet encoding translation and dilation conditions. This sequence is implemented on a 3 Tesla whole body Siemens scanner. Results  Compared to Fourier encoding, the proposed technique tested on phantoms with different shapes and structures, is able to provide gradient-echo reduced FOV images free from aliased signals. Conclusion  Wavelet encoding is suitable for small FOV imaging in dynamic MRI studies. Content Type Journal ArticleCategory Research ArticleDOI 10.1007/s10334-009-0193-zAuthors Hacene Serrai, National Research Council of Canada, Institute for Biodiagnostics 435 Ellice Avenue Winnipeg MB R3X 2C6 CanadaRichard Young, National Research Council of Canada, Institute for Biodiagnostics 435 Ellice Avenue Winnipeg MB R3X 2C6 Canada Journal Magnetic Resonance Materials in Physics, Biology and MedicineOnline ISSN 1352-8661Print ISSN 0968-5243 Journal Volume Volume 23 Journal Issue Volume 23, Number 1 / February, 2010
Combining RF encoding with parallel imaging: a simulation study
Sat, 19 Dec 2009 06:50:20 -0000
Abstract Object  The aim of this work was to investigate combining spatial encoding by radio frequency (RF) excitation with conventional parallel imaging (PI) methods to determine whether this could improve overall imaging performance. Materials and methods  A simulation framework was developed to predict imaging performance for regular, central and random under-sampled parallel imaging methods augmented by RF spatial signal modulation. Optimisation methods were used to find the RF modulation patterns that produce optimal image reconstruction using the condition number of the PI encoding matrix as a quality metric. The diverse patterns of raw data sampling produced were compared using a measure of data uniformity across k-space. Results  Regular under-sampling of k-space provided the best reconstruction quality. When other under-sampling schemes were employed then RF modulation could be used to improve reconstruction, with the optimum achieved by redistributing the signal in k-space to return to regular sub-sampling. For all tested under-sampling patterns, no further improvements in image quality were attained. Conclusion  Using the simulation framework and metrics described the interaction of different spatial encoding approaches could be investigated. Regular sub-sampling provided optimal reconstruction, independent of whether the spatial encoding was achieved by gradients only or a combination of gradient and RF. Content Type Journal ArticleCategory Research ArticleDOI 10.1007/s10334-009-0191-1Authors Rita G. Nunes, Hammersmith Campus, Imperial College Robert Steiner MR Unit, Imaging Sciences Department Du Cane Road London W12 0NN UKJoseph V. Hajnal, Hammersmith Campus, Imperial College Robert Steiner MR Unit, Imaging Sciences Department Du Cane Road London W12 0NN UKDavid J. Larkman, Hammersmith Campus, Imperial College Robert Steiner MR Unit, Imaging Sciences Department Du Cane Road London W12 0NN UK Journal Magnetic Resonance Materials in Physics, Biology and MedicineOnline ISSN 1352-8661Print ISSN 0968-5243 Journal Volume Volume 23 Journal Issue Volume 23, Number 1 / February, 2010

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