Systematic variations in polymer gel dosimeter calibration due to container influence and deviations from water equivalence.

abstract：:Range verification in proton therapy is a critical quality assurance task. We studied the feasibility of online range verification based on proton-induced acoustic signals, using a bidirectional long-short-term-memory recurrent neural network and various signal processing techniques. Dose distribution of 1D pencil pro...

journal_title：Physics in medicine and biology

authors： Yao S,Hu Z,Zhang X,Lou E,Liang Z,Wang Y,Peng H

更新日期：2020-11-05 00:00:00

abstract：:Voltage-sensitive dyes are an important tool in visualizing electrical activity in cardiac tissue. Until today, they have mainly been applied in cardiac electrophysiology to subsurface imaging. In the present study, we assess different imaging methods used in optical tomography with respect to their effectiveness in v...

journal_title：Physics in medicine and biology

authors： Bernus O,Wellner M,Mironov SF,Pertsov AM

更新日期：2005-01-21 00:00:00

abstract：:The National Physical Laboratory (NPL) provides a high-energy photon calibration service using 4-19 MV x-rays and 60Co gamma-radiation for secondary standard dosemeters in terms of absorbed dose to water. The primary standard used for this service is a graphite calorimeter and so absorbed dose calibrations must be con...

journal_title：Physics in medicine and biology

authors： Nutbrown RF,Duane S,Shipley DR,Thomas RA

更新日期：2002-02-07 00:00:00

abstract：:The aim of this study was to investigate the utility of consistency metrics, such as inverse consistency, in contour-based deformable registration error analysis. Four images were acquired of the same phantom that has experienced varying levels of deformation. The deformations were simulated with deformable image regi...

journal_title：Physics in medicine and biology

authors： Bender ET,Tomé WA

更新日期：2009-09-21 00:00:00

abstract：:A new method for correcting simultaneously the attenuation, scatter and resolution effects in SPECT has been developed for the case of a homogeneous medium. It is based on an effective model of the scatter process. This model depends on only four parameters which are determined experimentally and remain independent of...

journal_title：Physics in medicine and biology

authors： Walrand SH,van Elmbt LR,Pauwels S

更新日期：1994-04-01 00:00:00

abstract：:Investigate 3D (spatial and temporal) convolutional neural networks (CNNs) for real-time on-the-fly magnetic resonance imaging (MRI) reconstruction. In particular, we investigated the applicability of training CNNs on a patient-by-patient basis for the purpose of lung tumor segmentation. Data were acquired with our 3 ...

journal_title：Physics in medicine and biology

authors： Dietz B,Yun J,Yip E,Gabos Z,Fallone BG,Wachowicz K

更新日期：2019-09-23 00:00:00

abstract：:Mean glandular dose is the quantity used for dosimetry in mammography and depends on breast-related characteristics, such as thickness and density, and on the x-ray spectrum used for breast imaging. This work aims to present an experimentally-based method to derive polyenergetic normalized glandular dose coefficients ...

journal_title：Physics in medicine and biology

authors： Santos JC,Tomal A,de Barros N,Costa PR

更新日期：2019-05-10 00:00:00

abstract：:Ho-166 is a combined beta-gamma emitter of which the betas can be used therapeutically. From the 81 keV gammas of Ho-166, SPECT images can be obtained, which give opportunities to guide Ho-166 therapy. Accurate reconstruction of Ho-166 images is currently hampered by photopeak-scatter in the patient, down-scatter in t...

journal_title：Physics in medicine and biology

authors： de Wit TC,Xiao J,Nijsen JF,van het Schip FD,Staelens SG,van Rijk PP,Beekman FJ

更新日期：2006-10-07 00:00:00

abstract：:Experimental radiobiological investigations of fast neutron beams involve irradiation of thin cell layers. The irradiation of cells is done either in free air or with a material such as graphite, TE plastic or bone-equivalent plastic covering the cells. This paper discusses the computed dose distributions in LET at sh...

journal_title：Physics in medicine and biology

authors： Bhatia DP,Nagarajan PS

更新日期：1979-09-01 00:00:00

abstract：:Computer tomographic (CT) scans are used to correct for tissue inhomogeneities in radiotherapy treatment planning. In order to guarantee a precise treatment, it is important to obtain the relationship between CT Hounsfield units and electron densities (or proton stopping powers for proton radiotherapy), which is the b...

journal_title：Physics in medicine and biology

authors： Schneider U,Pedroni E,Lomax A

更新日期：1996-01-01 00:00:00

abstract：:In this study, two computational phantoms of the newborn patient were used to assess individual organ doses and effective doses delivered during head, chest, abdomen, pelvis, and torso examinations using the Siemens SOMATOM Sensation 16 helical multi-slice computed tomography (MSCT) scanner. The stylized phantom used ...

journal_title：Physics in medicine and biology

authors： Staton RJ,Lee C,Lee C,Williams MD,Hintenlang DE,Arreola MM,Williams JL,Bolch WE

更新日期：2006-10-21 00:00:00

abstract：:A formalism is proposed for the estimation of mean glandular dose for breast tomosynthesis, which is a simple extension of the UK, European and IAEA protocols for dosimetry in conventional projection mammography. The formalism introduces t-factors for the calculation of breast dose from a single projection and T-facto...

journal_title：Physics in medicine and biology

authors： Dance DR,Young KC,van Engen RE

更新日期：2011-01-21 00:00:00

abstract：:For low-energy (up to 150 kV) x-rays, the ratio of mass-energy absorption coefficients for water to air, (mu(en)/rho)w.air, and the backscatter factor B are used in the conversion of air kerma, measured free-in-air, to water kerma on the surface of a water phantom. For clinical radiotherapy, similar conversion factors...

journal_title：Physics in medicine and biology

authors： Ma CM,Seuntjens JP

更新日期：1999-01-01 00:00:00

abstract：:Diffuse optical imaging using non-ionizing radiation is a non-invasive method that shows promise towards breast cancer diagnosis. Hand-held optical imagers show potential for clinical translation of the technology, yet they have not been used towards 3D tomography. Herein, 3D tomography of human breast tissue in vivo ...

journal_title：Physics in medicine and biology

authors： Erickson SJ,Martinez SL,DeCerce J,Romero A,Caldera L,Godavarty A

更新日期：2013-03-07 00:00:00

abstract：:Beam tracking with scanned carbon ion radiotherapy achieves highly conformal target dose by steering carbon pencil beams to follow moving tumors using real-time magnetic deflection and range modulation. The purpose of this study was to evaluate the robustness of target dose coverage from beam tracking in light of posi...

journal_title：Physics in medicine and biology

authors： Eley JG,Newhauser WD,Richter D,Lüchtenborg R,Saito N,Bert C

更新日期：2015-02-21 00:00:00

abstract：:Fractional flow reserve (FFR) provides an objective physiological evaluation of stenosis severity. A technique that can measure FFR using only angiographic images would be a valuable tool in the cardiac catheterization laboratory. To perform this, the diseased blood flow can be measured with a first pass distribution ...

journal_title：Physics in medicine and biology

authors： Wong JT,Molloi S

更新日期：2008-07-21 00:00:00

abstract：:In carbon ion therapy treatment planning, the relative biological effectiveness (RBE) is accounted for by optimization of the RBE-weighted dose (biological dose). The RBE calculation methods currently applied clinically in carbon ion therapy are derived from the microdosimetric kinetic model (MKM) in Japan and the loc...

journal_title：Physics in medicine and biology

authors： Dahle TJ,Magro G,Ytre-Hauge KS,Stokkevåg CH,Choi K,Mairani A

更新日期：2018-11-12 00:00:00

abstract：:The temperature sensitivities of absorption and reduced scattering coefficients in the range 700-1000 nm are determined for the liquid phantom Intralipid using spatially resolved continuous wave measurements. The measurements were conducted on a 10 L heated volume of 1% Intralipid subjected to a 40-30 degrees C coolin...

journal_title：Physics in medicine and biology

authors： McGlone VA,Martinsen P,Künnemeyer R,Jordan B,Cletus B

更新日期：2007-05-07 00:00:00

abstract：:Temperature distributions resulting from hyperthermia treatments on isolated perfused bovine tongues were compared with simulations by a treatment planning system. The aim was to test whether the discrete vessel model used for the treatment planning is able to predict correct generic temperature distributions. Tongues...

journal_title：Physics in medicine and biology

authors： Raaymakers BW,Crezee J,Lagendijk JJ

更新日期：1998-05-01 00:00:00

abstract：:Breast cancer is one of the leading causes of female cancer deaths. Early diagnosis with prophylactic may improve the patients' prognosis. So far ultrasound (US) imaging is a popular method in breast cancer diagnosis. However, its accuracy is bounded to traditional handcrafted feature methods and expertise. A novel me...

journal_title：Physics in medicine and biology

authors： Xie J,Song X,Zhang W,Dong Q,Wang Y,Li F,Wan C

更新日期：2020-10-29 00:00:00

abstract：:Deformable image registration is widely used in various radiation therapy applications including daily treatment planning adaptation to map planned tissue or dose to changing anatomy. In this work, a simple and efficient inverse consistency deformable registration method is proposed with aims of higher registration ac...

journal_title：Physics in medicine and biology

authors： Yang D,Li H,Low DA,Deasy JO,El Naqa I

更新日期：2008-11-07 00:00:00

abstract：:The dosimetrical characteristics of a new miniature multileaf collimator (ModuLeaf MLC, MRC Systems GmbH, Heidelberg, Germany) attached to the accessory holder of a Siemens accelerator with 6 MV x-rays (PRIMUS, Siemens OCS, Concord, California, USA) have been investigated. In particular, those parameters which are imp...

journal_title：Physics in medicine and biology

authors： Hartmann GH,Föhlisch F

更新日期：2002-06-21 00:00:00

abstract：:K line x-ray fluorescence (KXRF) measurements of bone lead have emerged as a promising new biological marker of internal lead dose in epidemiological studies. Some disagreements exist, however, over the analysis of data at low levels of bone lead concentration. In this study, we performed 30 serial measurements on eac...

journal_title：Physics in medicine and biology

authors： Kim R,Aro A,Rotnitzky A,Amarasiriwardena C,Hu H

更新日期：1995-09-01 00:00:00

abstract：:Novel x-ray medical imaging sensors, such as photon counting detectors (PCDs) and large area CCD and CMOS cameras can involve irregular and/or sparse sampling of the detector plane. Application of such detectors to CT involves undersampling that is markedly different from the commonly considered case of sparse angular...

journal_title：Physics in medicine and biology

authors： Sisniega A,Zbijewski W,Stayman JW,Xu J,Taguchi K,Fredenberg E,Lundqvist M,Siewerdsen JH

更新日期：2016-01-07 00:00:00

abstract：:The class of non-rigid registration methods proposed in the framework of PDE-constrained large deformation diffeomorphic metric mapping is a particularly interesting family of physically meaningful diffeomorphic registration methods. Inexact Gauss-Newton-Krylov optimization has shown an excellent numerical accuracy an...

journal_title：Physics in medicine and biology

authors： Hernandez M

更新日期：2019-01-07 00:00:00

abstract：:The objective of this study was to be able to distinguish between healthy skin tissue and malignant ones, furthermore determining a unique pattern of roughness for each skin lesion by microtopographic analysis of the skin surface of Mexican patients during the period from April to October 2002. The standard technique ...

journal_title：Physics in medicine and biology

authors： del Carmen López Pacheco M,da Cunha Martins-Costa MF,Zapata AJ,Cherit JD,Gallegos ER

更新日期：2005-12-07 00:00:00

abstract：:An inflatable endorectal balloon (ERB) is often used during stereotactic body radiation therapy (SBRT) for treatment of prostate cancer in order to reduce both intrafraction motion of the target and risk of rectal toxicity. However, the ERB can exert significant force on the prostate, and this work assessed the impact...

journal_title：Physics in medicine and biology

authors： Jones BL,Gan G,Kavanagh B,Miften M

更新日期：2013-11-21 00:00:00

abstract：:A near-field probe is described that enables high spatial resolution imaging with terahertz (THz) pulses. The spatial resolution capabilities of the system lie in the range of few microns and we demonstrate a resolution of 7 microm using broad-banded THz pulses with an intensity maximum near 0.5 THz. We present a stud...

journal_title：Physics in medicine and biology

authors： Federici JF,Mitrofanov O,Lee M,Hsu JW,Brener I,Harel R,Wynn JD,Pfeiffer LN,West KW

更新日期：2002-11-07 00:00:00

abstract：:Sensing and enumeration of specific types of circulating cells in small animals is an important problem in many areas of biomedical research. Microscopy-based fluorescence in vivo flow cytometry methods have been developed previously, but these are typically limited to sampling of very small blood volumes, so that ver...

journal_title：Physics in medicine and biology

authors： Zettergren E,Swamy T,Runnels J,Lin CP,Niedre M

更新日期：2012-07-21 00:00:00

abstract：:Four-dimensional computed tomography (4D-CT) requires breathing information from the patient, and for this, several systems are available. Testing of these systems, under realistic conditions, requires a phantom with a moving target and an expandable outer contour. An anthropomorphic phantom was developed to simulate ...

journal_title：Physics in medicine and biology

authors： Vásquez AC,Runz A,Echner G,Sroka-Perez G,Karger CP

更新日期：2012-05-07 00:00:00