Correction of microwave-induced thermistor sensor errors.

abstract：:In prostate seed implants, radioactive seeds are implanted into the prostate through a guiding needle with the help of a template and real-time imaging. The ideal locations of the guiding needles and the relative positions of the seeds in each needle are determined before the implantation under the assumption that the...

journal_title：Medical physics

authors： Nath S,Chen Z,Yue N,Trumpore S,Peschel R

更新日期：2000-05-01 00:00:00

abstract：:A doorless entry system has been designed for use in high-energy radiation therapy rooms. The doorless entry improves patient access, safety and throughput, increases the physical safety for the radiation therapists, and avoids the significant cost of heavy shielding doors. The design meets concerns relating to radiat...

journal_title：Medical physics

authors： Dawson DJ,Wissing WW,Tonks RE

更新日期：1998-02-01 00:00:00

abstract：:The paper presents a theoretical derivation of the photon fluence simulation efficiency in photon beam treatment head simulations without and with bremsstrahlung splitting. The expressions obtained provide a rigorous explanation of the efficiency dependence on scoring zone size and splitting number and explain the lar...

journal_title：Medical physics

authors： Kawrakow I

更新日期：2005-07-01 00:00:00

abstract：PURPOSE:Atherosclerosis of peripheral cerebral arteries can lead to stroke either by stenosis formation or plaque rupture. This pathology is initiated by the alteration of arterial wall mechanical properties shown to be assessable by ultrasound elastography. Recently, noninvasive vascular elastography (NIVE) was introd...

journal_title：Medical physics

authors： Mercure E,Deprez JF,Fromageau J,Basset O,Soulez G,Cloutier G,Maurice RL

更新日期：2011-02-01 00:00:00

abstract：PURPOSE:The x-ray performance evaluation of digital x-ray detectors is based on the calculation of the modulation transfer function (MTF), the noise power spectrum (NPS), and the resultant detective quantum efficiency (DQE). The flat images used for the extraction of the NPS should not contain any fixed pattern noise (...

journal_title：Medical physics

authors： Konstantinidis AC,Olivo A,Speller RD

更新日期：2011-12-01 00:00:00

abstract：PURPOSE:The aim of this work is to investigate the predictive power of a common conventional intensity modulated radiation therapy (IMRT) quality assurance (QA) performance metric, the gamma passing rate (%GP), through the analysis of the sensitivity and of the correlation between %GP and different dose discrepancies b...

journal_title：Medical physics

authors： Stasi M,Bresciani S,Miranti A,Maggio A,Sapino V,Gabriele P

更新日期：2012-12-01 00:00:00

abstract：:In addition to the familiar problems of reduced contrast and signal-to-noise ratio (SNR) in the single energy case, dual-energy subtractions in the presence of scattered radiation suffer further degradations from: (1) artifacts due to nonuniform subtraction of scatter, and (2) a serious deterioration of the signal of ...

journal_title：Medical physics

authors： Wagner FC,Macovski A,Nishimura DG

更新日期：1988-09-01 00:00:00

abstract：PURPOSE:The small number of samples available for training and testing is often the limiting factor in finding the most effective features and designing an optimal computer-aided diagnosis (CAD) system. Training on a limited set of samples introduces bias and variance in the performance of a CAD system relative to that...

journal_title：Medical physics

authors： Way TW,Sahiner B,Hadjiiski LM,Chan HP

更新日期：2010-02-01 00:00:00

abstract：PURPOSE:To characterize a new air vented ionization chamber technology, suitable to build detector arrays with small pixel pitch and independence of sensitivity on dose per pulse. METHODS:The prototype under test is a linear array of air vented ionization chambers, consisting of 80 pixels with 3.5 mm pixel pitch dista...

journal_title：Medical physics

authors： Togno M,Wilkens JJ,Menichelli D,Oechsner M,Perez-Andujar A,Morin O

更新日期：2016-05-01 00:00:00

abstract：PURPOSE:Until recently the treatment verification for patients undergoing fast neutron therapy at our facility was accomplished through a combination of neutron beam portal films aligned with a graticule mounted on an orthronormal x-ray tube. To eliminate uncertainty with respect to the relative positions of the x-ray ...

journal_title：Medical physics

authors： Halford R,Snyder M

更新日期：2012-06-01 00:00:00

abstract：:Multimodality NIR spectroscopy systems offer the possibility of region-based vascular and molecular characterization of tissue in vivo. However, computationally efficient 3D image reconstruction algorithms specific to these image-guided systems currently do not exist. Image reconstruction is often based on finite-elem...

journal_title：Medical physics

authors： Srinivasan S,Pogue BW,Carpenter C,Yalavarthy PK,Paulsen K

更新日期：2007-11-01 00:00:00

abstract：PURPOSE:X-ray fluorescence computed tomography (XFCT) experiments have typically used pencil beams for data acquisition, which yielded good quality images of gold nanoparticles (AuNP) but prolonged the imaging time. Here we propose three novel collimator geometries for use with faster sheet beam XFCT data acquisition. ...

journal_title：Medical physics

authors： Dunning CAS,Bazalova-Carter M

更新日期：2018-06-01 00:00:00

abstract：:Recently, portal imaging systems have been successfully demonstrated in dosimetric treatment verification applications, where measured and predicted images are quantitatively compared. To advance this approach to dosimetric verification, a two-step model which predicts dose deposition in arbitrary portal image detecto...

journal_title：Medical physics

authors： McCurdy BM,Pistorius S

更新日期：2000-09-01 00:00:00

abstract：PURPOSE:Hybrid Photon Counting (HPC) detectors profoundly improved x-ray diffraction experiments at third generation synchrotron facilities. Enabling the simultaneous measurement of x-ray intensities in multiple energy bins, they also have many potential applications in the field of medical imaging. A prerequisite for ...

journal_title：Medical physics

authors： Trueb P,Zambon P,Broennimann C

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Incorporating training into image segmentation is a good approach to achieve additional robustness. This work aims to develop an effective strategy to utilize shape prior knowledge, so that the segmentation label evolution can be driven toward the desired global optimum. METHODS:In the variational image segmen...

journal_title：Medical physics

authors： Zhao T,Ruan D

更新日期：2016-05-01 00:00:00

abstract：:Effective radioimmunotherapy may depend on a priori knowledge of the radiation absorbed dose distribution obtained by trace imaging activities administered to a patient before treatment. A new, fast, and effective treatment planning approach is developed to deal with a heterogeneous activity distribution. Calculation ...

journal_title：Medical physics

authors： Erdi AK,Yorke ED,Loew MH,Erdi YE,Sarfaraz M,Wessels BW

更新日期：1998-11-01 00:00:00

abstract：PURPOSE:To construct a Monte Carlo (MC)-based simulation model for analyzing the dependence of tumor oxygen distribution on different variables related to tumor vasculature [blood velocity, vessel-to-vessel proximity (vessel proximity), and inflowing oxygen partial pressure (pO2)]. METHODS:A voxel-based tissue model c...

journal_title：Medical physics

authors： Lagerlöf JH,Kindblom J,Bernhardt P

更新日期：2014-09-01 00:00:00

abstract：PURPOSE:We describe the acceptance testing, commissioning, periodic quality assurance, and workflow procedures developed for the first clinically implemented magnetic resonance imaging-guided radiation therapy (MR-IGRT) system for real-time tracking and beam control. METHODS:The system utilizes real-time cine imaging ...

journal_title：Medical physics

authors： Green OL,Rankine LJ,Cai B,Curcuru A,Kashani R,Rodriguez V,Li HH,Parikh PJ,Robinson CG,Olsen JR,Mutic S,Goddu SM,Santanam L

更新日期：2018-05-28 00:00:00

abstract：:The computed tomography (CT) radiation dose to pediatric patients has received considerable attention recently. Moreover, it is important to be able to determine CT radiation doses for various patient sizes ranging from infants to large adults. The current AAPM protocol only measures CT radiation dose using a 16 cm ac...

journal_title：Medical physics

authors： Nickoloff EL,Dutta AK,Lu ZF

更新日期：2003-03-01 00:00:00

abstract：:When treating prostate cancer using high dose rate (HDR) brachytherapy, overdosing the rectal wall may lead to post-treatment rectal complications. An area of concern is related to how the rectal wall dose is calculated by treatment planning systems (TPSs). TPSs are used to calculate the dose delivered to the rectal w...

journal_title：Medical physics

authors： Kwan IS,Wilkinson D,Cutajar D,Lerch M,Rosenfeld A,Howie A,Bucci J,Chin Y,Perevertaylo VL

更新日期：2009-01-01 00:00:00

abstract：:A new calibration algorithm (GLAaS) to derive absolute dose maps from images acquired with the Varian PV-aS500 electronic portal imager (based on amorphous silicon detectors) has been developed incorporating the dependence of detector response on primary and transmitted radiation and on field size. Detector calibratio...

journal_title：Medical physics

authors： Nicolini G,Fogliata A,Vanetti E,Clivio A,Cozzi L

更新日期：2006-08-01 00:00:00

abstract：:Soft-tissue detectability in cone-beam computed tomography (CBCT) was evaluated via two-alternative forced-choice (2AFC) tests. Investigations included the dependence of detectability on radiation dose, the influence of the asymmetric three-dimensional (3D) noise-power spectrum (NPS) in axial and sagittal or coronal p...

journal_title：Medical physics

authors： Tward DJ,Siewerdsen JH,Daly MJ,Richard S,Moseley DJ,Jaffray DA,Paul NS

更新日期：2007-11-01 00:00:00

abstract：PURPOSE:Radiation Therapy (RT) induced pulmonary function change may depend on the location, underlying function of that lung prior to radiations, radiation dose/fractionation and other factors. We propose to evaluate the radiation induced pulmonary function change using static breath-hold MRI scans with vascular infor...

journal_title：Medical physics

authors： Ding K,Cao K,Du K,Chen Q,Ennis D,Christensen G,Reinhardt J,Libby B,Benedict S,Sheng K

更新日期：2012-06-01 00:00:00

abstract：:Computed tomography is sensitive to changes in the imaged distribution during acquisition of the projection data. Previous investigations have emphasized discrete or discontinuous changes in the imaged object. Recent advances have motivated our investigation of object time-dependence characterized by a continuous func...

journal_title：Medical physics

authors： Holden JE,Ip WR

更新日期：1978-11-01 00:00:00

abstract：PURPOSE:To describe a method for combining sliding window plans [intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT)] for use in treatment plan averaging, which is needed for Pareto surface navigation based multicriteria treatment planning. METHODS:The authors show that by taking an...

journal_title：Medical physics

authors： Craft D,Papp D,Unkelbach J

更新日期：2014-02-01 00:00:00

abstract：:Multielectrode cochlear implantation is the most effective treatment for profound sensorineural hearing loss. In vivo three-dimensional 3-D localization of cochlear implant electrodes is important for modeling of the electrical field in the cochlea, design of electrode arrays, and may improve speech processor programm...

journal_title：Medical physics

authors： Yang S,Wang G,Skinner MW,Rubinstein JT,Vannier MW

更新日期：2000-04-01 00:00:00

abstract：:For obliquely incident photon beams, the buildup of dose with depth is markedly different from normally incident beams. However, relatively little data on this topic exists for high-energy photon beams of energy greater than 6 MV. Measurements of dose in the buildup region were made using a plane-parallel ionization c...

journal_title：Medical physics

authors： Gerbi BJ,Meigooni AS,Khan FM

更新日期：1987-05-01 00:00:00

abstract：PURPOSE:Particle therapy is becoming increasingly available world-wide for precise tumor targeting, its favorable depth dose deposition, and increased biological damage to tumor tissue compared to conventional photon therapy. As demand increases for improved robustness and conformality, next-generation secondary dose c...

journal_title：Medical physics

authors： Kopp B,Fuglsang Jensen M,Mein S,Hoffmann L,Nyström H,Falk M,Haberer T,Abdollahi A,Debus J,Mairani A

更新日期：2020-10-01 00:00:00

abstract：PURPOSE:The previously described 2D standardized vessel-wall-plus-plaque thickness (VWT) maps constructed from 3D ultrasound vessel wall measurements using an arc-length (AL) scaling approach adjusted the geometric variability of carotid arteries and has allowed for the comparisons of VWT distributions in longitudinal ...

journal_title：Medical physics

authors： Chen Y,Chiu B

更新日期：2016-12-01 00:00:00

abstract：PURPOSE:Total variation minimization (TVM) is a popular and useful method for accurate CT reconstruction from few-views and limited-angle data. However, the optimization procedure of previous TVM-based algorithms is very time-consuming. The purpose of this paper was to accelerate the high image quality CT reconstructio...

journal_title：Medical physics

authors： Hou X,Teng Y,Kang Y,Qi S

更新日期：2018-02-01 00:00:00