Proof-of-concept delivery of intensity modulated arc therapy on the Elekta Unity 1.5 T MR-linac.

abstract：:The authors have developed an apparatus able to generate ID intensity-modulated beams, using only one moving absorber within the irradiation field. A procedure for deriving optimized absorber-speed profiles in order to produce the desired fluence/dose profiles has been suggested. Experimental tests show that the syste...

journal_title：Physics in medicine and biology

authors： Fiorino C,Lev A,Fusca M,Cattaneo GM,Rudello F,Calandrino R

更新日期：1995-02-01 00:00:00

abstract：:Simultaneous near-infrared spectroscopy (NIRS) and magnetic resonance imaging (MRI) were used to investigate the correlation between tumour vascular oxygenation and tissue oxygen tension dynamics in rat breast 13762NF tumours with respect to hyperoxic gas breathing. NIRS directly detected global variations in the oxyg...

journal_title：Physics in medicine and biology

authors： Xia M,Kodibagkar V,Liu H,Mason RP

更新日期：2006-01-07 00:00:00

abstract：:The reference levels for testing compliance of human exposure with radio-frequency (RF) safety limits have been derived from very simplified models of the human. In order to validate these findings for anatomical models, we investigated the absorption characteristics for various anatomies ranging from 6 year old child...

journal_title：Physics in medicine and biology

authors： Kühn S,Jennings W,Christ A,Kuster N

更新日期：2009-02-21 00:00:00

abstract：:The cerebral arteries are difficult to reproduce from first principles, featuring interwoven territories, and intricate layers of grey and white matter with differing metabolic demand. The aim of this study was to identify the ideal configuration of arteries required to sustain an entire brain hemisphere based on mini...

journal_title：Physics in medicine and biology

authors： Keelan J,Chung EML,Hague JP

更新日期：2019-06-21 00:00:00

abstract：:Picking geometrically relevant atlases from the whole training set is crucial to multi-atlas based image segmentation, especially with extensive data of heterogeneous quality in the Big Data era. Unfortunately, there is very limited understanding of how currently used image similarity criteria reveal geometric relevan...

journal_title：Physics in medicine and biology

authors： Zhao T,Ruan D

更新日期：2016-06-07 00:00:00

abstract：:Cavity theories are used to relate the dose in a medium to the dose in a cavity. No satisfactory analytical approach exists for the case of intermediate cavities, such as TLDs, when interface effects are important. Burlin proposed a general cavity theory that accounts for the cavity size but which ignores interface ef...

journal_title：Physics in medicine and biology

authors： Frujinoiu C

更新日期：2001-04-01 00:00:00

abstract：:Ultrasound Doppler (UD) velocity measurements are commonly used to quantify blood flow velocities in vivo. The aim of our work was to investigate the accuracy of in vivo spectral Doppler measurements of velocity waveforms. Waveforms were derived from spectral Doppler signals and corrected for intrinsic spectral broade...

journal_title：Physics in medicine and biology

authors： Jiang J,Strother C,Johnson K,Baker S,Consigny D,Wieben O,Zagzebski J

更新日期：2011-03-21 00:00:00

abstract：:Scatter correction is an essential technique to improve the image quality of cone-beam CT (CBCT). Although different scatter correction methods have been proposed in the literature, a standard solution is still being studied due to the limitations including accuracy, computation efficiency and generalization. In this ...

journal_title：Physics in medicine and biology

authors： Jiang Y,Yang C,Yang P,Hu X,Luo C,Xue Y,Xu L,Hu X,Zhang L,Wang J,Sheng K,Niu T

更新日期：2019-07-11 00:00:00

abstract：:Sparse-view CT reconstruction algorithms via total variation (TV) optimize the data iteratively on the basis of a noise- and artifact-reducing model, resulting in significant radiation dose reduction while maintaining image quality. However, the piecewise constant assumption of TV minimization often leads to the appea...

journal_title：Physics in medicine and biology

authors： Niu S,Gao Y,Bian Z,Huang J,Chen W,Yu G,Liang Z,Ma J

更新日期：2014-06-21 00:00:00

abstract：:Calculations indicate that an assembly consisting of an antimony-beryllium source at the centre of a 4 cm radius water sphere surrounded by a 1 mm thick shell of boron-10 will emit neutrons with a broad spectrum at intermediate energies. A device based on this design was constructed using a water-filled, boron-carbide...

journal_title：Physics in medicine and biology

authors： Harvey JR,Bending RC

更新日期：1976-01-01 00:00:00

abstract：:Several applications in nuclear medicine require absolute activity quantification of single photon emission computed tomography images. Obtaining a repeatable calibration factor that converts voxel values to activity units is essential for these applications. Because source preparation and measurement of the source ac...

journal_title：Physics in medicine and biology

authors： Anizan N,Wang H,Zhou XC,Wahl RL,Frey EC

更新日期：2015-02-07 00:00:00

abstract：:The theory of task-based assessment of image quality is reviewed in the context of imaging with ionizing radiation, and objective figures of merit (FOMs) for image quality are summarized. The variation of the FOMs with the task, the observer and especially with the mean number of photons recorded in the image is discu...

journal_title：Physics in medicine and biology

authors： Barrett HH,Myers KJ,Hoeschen C,Kupinski MA,Little MP

更新日期：2015-01-21 00:00:00

abstract：:In this paper the propagation of a UWB pulse into a layered model of the human body is studied to characterize absorption and reflection of the UWB signal due to the different body tissues. Several time behaviours for the incident UWB pulse are considered and compared with reference to the feasibility of breath and he...

journal_title：Physics in medicine and biology

authors： Cavagnaro M,Pittella E,Pisa S

更新日期：2013-12-21 00:00:00

abstract：:The treatment planning process for patients with head and neck (H&N) cancer is regarded as one of the most complicated due to large target volume, multiple prescription dose levels, and many radiation-sensitive critical structures near the target. Treatment planning for this site requires a high level of human experti...

journal_title：Physics in medicine and biology

authors： Nguyen D,Jia X,Sher D,Lin MH,Iqbal Z,Liu H,Jiang S

更新日期：2019-03-18 00:00:00

abstract：:The biological mechanisms of platelet destruction must be correctly identified before platelet survival curves can be interpreted. This report develops a theory of platelet destruction which is compared with experiments performed on platelets labelled with the radioactive isotope 51Cr. Platelet destruction rate is a c...

journal_title：Physics in medicine and biology

authors： Trowbridge EA,Martin JF

更新日期：1983-12-01 00:00:00

abstract：:The signal properties of polycrystalline mercuric iodide (HgI2) film detectors, under irradiation conditions relevant to mammographic, radiographic, fluoroscopic and radiotherapy x-ray imaging, are reported. Each film detector consists of an approximately 230 to approximately 460 microm thick layer of HgI2 (fabricated...

journal_title：Physics in medicine and biology

authors： Su Z,Antonuk LE,El-Mohri Y,Hu L,Du H,Sawant A,Li Y,Wang Y,Yamamoto J,Zhao Q

更新日期：2005-06-21 00:00:00

abstract：:In this paper, we have investigated the feasibility of imaging the mechanical behavior of poroelastic materials using axial strain elastography. Cylindrical samples obtained from poroelastic materials having different elastic and permeability properties were subjected to a constant compression force (a classical creep...

journal_title：Physics in medicine and biology

authors： Righetti R,Righetti M,Ophir J,Krouskop TA

更新日期：2007-06-07 00:00:00

abstract：:Electromagnetic tracking technology is primarily used for continuous prostate localization during radiotherapy, but offers potential value for evaluation of dosimetric coverage and adequacy of treatment for dynamic targets. We developed a highly automated method for daily computation of cumulative dosimetric effects o...

journal_title：Physics in medicine and biology

authors： Noel CE,Santanam L,Olsen JR,Baker KW,Parikh PJ

更新日期：2010-01-07 00:00:00

abstract：:Numerical computations are used to evaluate electric field dosimetry for high-resolution anatomically based inhomogeneous models of a human male child, and male and female rats and mice, under exposure to 60 Hz uniform magnetic field sources of three perpendicular orientations. The goal is to compare the child data to...

journal_title：Physics in medicine and biology

authors： Dawson TW,Caputa K,Stuchly MA

更新日期：2002-07-21 00:00:00

abstract：:Respiratory research with mice using micro-computed tomography (micro-CT) has been predominantly hindered by the limited resolution and signal-to-noise ratio (SNR) as a result of respiratory motion artefacts. In this study, we develop a novel technique for capturing the lung microstructure in vivo using micro-CT, thro...

journal_title：Physics in medicine and biology

authors： Namati E,Chon D,Thiesse J,Hoffman EA,de Ryk J,Ross A,McLennan G

更新日期：2006-12-07 00:00:00

abstract：:The influence of the angular response of radiometer probes on measurements of irradiance in ultraviolet phototherapy has been studied. Irradiance measurements were made using nine ultraviolet (UV) radiometers employed by phototherapy centres in Scotland and Northern Ireland, and compared with measurements made using t...

journal_title：Physics in medicine and biology

authors： Martin CJ,Currie GD,Pye SD

更新日期：1999-04-01 00:00:00

abstract：:Enabling automated pipelines, image analysis and big data methodology in cancer clinics requires thorough understanding of the data. Automated quality assurance steps could improve the efficiency and robustness of these methods by verifying possible data biases. In particular, in head and neck (H&N) computed-tomograph...

journal_title：Physics in medicine and biology

authors： Welch ML,McIntosh C,Purdie TG,Wee L,Traverso A,Dekker A,Haibe-Kains B,Jaffray DA

更新日期：2020-01-10 00:00:00

abstract：:The distribution and transport of Hippuran is discussed. The activity leaving both kidneys has been calculated and compared with the bladder activity. It is shown that the Impulse Response Function of the ureter and bladder may be obtained by deconvolution, and data are presented relating to studies on one patient. ...

journal_title：Physics in medicine and biology

authors： Knesaurek K,Spaventi S

更新日期：1981-03-01 00:00:00

abstract：:The intra- and inter-batch accuracy and precision of MRI (polyacrylamide gelatin gel fabricated at atmospheric conditions) polymer gel dosimeters are assessed in full 3D. In the intra-batch study, eight spherical flasks were filled with the same polymer gel along with a set of test tubes that served as calibration pha...

journal_title：Physics in medicine and biology

authors： Vandecasteele J,De Deene Y

更新日期：2013-01-07 00:00:00

abstract：:Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using ...

journal_title：Physics in medicine and biology

authors： Kadrmas DJ,Frey EC,Karimi SS,Tsui BM

更新日期：1998-04-01 00:00:00

abstract：:Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a valuable tool for assessing treatment response to novel cancer therapeutics. With appropriate data acquisition, quantitative functional parameter estimates can be obtained by fitting a model to the data. This research focuses on applying a dual-input ...

journal_title：Physics in medicine and biology

authors： Orton MR,Miyazaki K,Koh DM,Collins DJ,Hawkes DJ,Atkinson D,Leach MO

更新日期：2009-04-07 00:00:00

abstract：:Irreversible electroporation (IRE) is a minimally invasive tumor therapy using pulsed electric field with high intensity while the important tissues such as blood vessel, bile duct, and nerve are preserved. In addition to ablation area, reversible electroporation (RE) region is also generated using needle electrodes f...

journal_title：Physics in medicine and biology

authors： Lv Y,Tang X,Peng W,Cheng X,Chen S,Yao C

更新日期：2020-10-14 00:00:00

abstract：:A two-probe technique has been developed to measure 125I in the thyroid. In this technique simultaneous emissions from a source are detected as coincidence events between two probes rather than as a sum peak in a single probe (the sum peak method). The background count rate when counting coincidence events between pro...

journal_title：Physics in medicine and biology

authors： Burns PA,Peggie JR

更新日期：1980-05-01 00:00:00

abstract：:A common dose-saving technique used in modern CT devices is automatic tube current modulation (TCM), which was originally designed to also reduce the dose in paediatric CT patients. In order to be able to deduce detailed organ doses of paediatric models, dose conversion coefficients normalized to CTDI(vol) for an eigh...

journal_title：Physics in medicine and biology

authors： Schlattl H,Zankl M,Becker J,Hoeschen C

更新日期：2012-10-21 00:00:00

abstract：:Positron emission tomography (PET) iterative 3D reconstruction is a very computational demanding task. One of the main issues of the iterative reconstruction concerns the management of the system response matrix (SRM). The SRM models the relationship between the projection and the voxel space and its memory footprint ...

journal_title：Physics in medicine and biology

authors： Camarlinghi N,Sportelli G,Guerra AD,Belcari N

更新日期：2018-09-28 00:00:00