Sci-Fri PM: Planning-04: Dose escalation study using anatomy-based aperture IMRT and SPECT perfusion images for lung cancer.

abstract：:The aim of this study is to perform a statistical analysis to verify the calculated percentage depth dose (PDD) based on the tissue maximum ratio (TMR) with the PDD measurements taken in water. 6 and 15 MV photon beams produced by a Varian linear 2100 C/D accelerator were used. PDDs and TMRs were measured at various d...

journal_title：Medical physics

authors： Isa M,Iqbal K,Afzal M,Buzdar S,Chow J

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:Credentialing can have an impact on whether or not a clinical trial produces useful quality data that is comparable between various institutions and scanners. With the recent increase of dynamic contrast enhanced-computed tomography (DCE-CT) usage as a companion biomarker in clinical trials, effective quality a...

journal_title：Medical physics

authors： Driscoll B,Keller H,Jaffray D,Coolens C

更新日期：2013-08-01 00:00:00

abstract：PURPOSE:The aim of this study was to demonstrate a new model for implementing a transit dosimetry system as a means of in vivo dose verification with a water equivalent electronic portal imaging device (WE-EPID) and a conventional treatment planning system (TPS). METHOD AND MATERIALS:A standard amorphous silicon (a-Si...

journal_title：Medical physics

authors： Deshpande S,Blake SJ,Xing A,Metcalfe PE,Holloway LC,Vial P

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:Due to the low contrast, blurry boundaries, and large amount of shadows in breast ultrasound (BUS) images, automatic tumor segmentation remains a challenging task. Deep learning provides a solution to this problem, since it can effectively extract representative features from lesions and the background in BUS i...

journal_title：Medical physics

authors： Hu Y,Guo Y,Wang Y,Yu J,Li J,Zhou S,Chang C

更新日期：2019-01-01 00:00:00

abstract：:With the increasing complexity of dose patterns external beam radiotherapy, there is a great need for new types of dosimeters. We studied the first prototype of a new dosimeter array consisting of water-equivalent plastic scintillating fibers for dose measurement in external beam radiotherapy. We found that this array...

journal_title：Medical physics

authors： Archambault L,Beddar AS,Gingras L,Lacroix F,Roy R,Beaulieu L

更新日期：2007-05-01 00:00:00

abstract：:For Monte Carlo linac simulations and patient dose calculations, it is important to accurately determine the phase space parameters of the initial electron beam incident on the target. These parameters, such as mean energy and radial intensity distribution, have traditionally been determined by matching the calculated...

journal_title：Medical physics

authors： Aljarrah K,Sharp GC,Neicu T,Jiang SB

更新日期：2006-04-01 00:00:00

abstract：:We report on some extensions and further developments of a well-known microcalcification detection algorithm based on adaptive noise equalization. Tissue equivalent phantom images with and without labeled microcalcifications were subjected to this algorithm, and analyses of results revealed some shortcomings in the ap...

journal_title：Medical physics

authors： Gürün OO,Fatouros PP,Kuhn GM,de Paredes ES

更新日期：2001-04-01 00:00:00

abstract：PURPOSE:The need for an accurate lesion segmentation tool in 18FDG PET is a prerequisite for the estimation of lesion response to therapy, for radionuclide dosimetry, and for the application of 18FDG PET to radiotherapy planning. In this work, the authors have developed an iterative method based on a mathematical fit d...

journal_title：Medical physics

authors： Nehmeh SA,El-Zeftawy H,Greco C,Schwartz J,Erdi YE,Kirov A,Schmidtlein CR,Gyau AB,Larson SM,Humm JL

更新日期：2009-10-01 00:00:00

abstract：:A general expression is derived for the NMR signal from a fluid undergoing random directional flow such as encountered within the microcirculation. The dependence of the echo amplitude on flow velocity, sample morphology, and experimental parameters are described in terms of a temporal velocity autocorrelation functio...

journal_title：Medical physics

authors： Kennan RP,Gao JH,Zhong J,Gore JC

更新日期：1994-04-01 00:00:00

abstract：PURPOSE:In this study, a dedicated device for ion chamber measurements of absorbed dose-to-water for a Nucletron microSelectron-v2 HDR (192)Ir brachytherapy source is presented. The device uses two ionization chambers in a so-called sandwich assembly. Using this setup and by taking the average reading of the two chambe...

journal_title：Medical physics

authors： Araki F,Kouno T,Ohno T,Kakei K,Yoshiyama F,Kawamura S

更新日期：2013-09-01 00:00:00

abstract：:A clamp-on current probe utilizing the Hall effect was used to determine x-ray tube current. This noninvasive technique was compared to two other methods of mA measurement: the Machlett Dynalyzer and the mR/mAs linearity method. Three diagnostic x-ray units were used in the comparison; two modern three-phase rooms and...

journal_title：Medical physics

authors： Atherton JV,Nickoloff EL

更新日期：1987-03-01 00:00:00

abstract：PURPOSE:Patient-specific IMRT QA measurements are important components of processes designed to identify discrepancies between calculated and delivered radiation doses. Discrepancy tolerance limits are neither well defined nor consistently applied across centers. The AAPM TG-218 report provides a comprehensive review a...

journal_title：Medical physics

authors： Miften M,Olch A,Mihailidis D,Moran J,Pawlicki T,Molineu A,Li H,Wijesooriya K,Shi J,Xia P,Papanikolaou N,Low DA

更新日期：2018-04-01 00:00:00

abstract：:The analysis and understanding of results of computed tomography (CT) require an understanding of photon attenuation in matter. The high sensitivity and resolution of these devices coupled with the use of a polychromatic photon source require a level and breadth of understanding about photon attenuation not usually re...

journal_title：Medical physics

authors： McCullough EC

更新日期：1975-11-01 00:00:00

abstract：:A theoretical model is described for application in ultrasonic tissue characterization using a calibrated 2-D spectrum analysis method. This model relates 2-D spectra computed from ultrasonic backscatter signals to intrinsic physical properties of tissue microstructures, e.g., size, shape, and acoustic impedance. The ...

journal_title：Medical physics

authors： Liu T,Lizzi FL,Ketterling JA,Silverman RH,Kutcher GJ

更新日期：2007-03-01 00:00:00

abstract：:Pixel size is of great interest in the flat-panel detector design because of its potential impact on image quality. In the particular case of angiographic x-ray fluoroscopy, small pixels are required in order to adequately visualize interventional devices such as guidewires and stents which have wire diameters as smal...

journal_title：Medical physics

authors： Jiang Y,Wilson DL

更新日期：2006-03-01 00:00:00

abstract：:Imaging parameters associated with a clinical magnetic resonance imaging (MRI) system, evaluated with the use of simple and inexpensive phantoms, are described in evaluation of a clinical MRI system. Images, obtained with a Diasonics 0.35-T MRI system using an elliptical whole-body radio frequency coil, are presented ...

journal_title：Medical physics

authors： Brateman L,Jennings LW,Nunnally RL,Vaughan JT

更新日期：1986-07-01 00:00:00

abstract：:Previous ultrasound tomography work conducted by our group showed a direct correlation between measured sound speed and physical density in vitro, and increased in vivo sound speed with increasing mammographic density, a known risk factor for breast cancer. Building on these empirical results, the purpose of this work...

journal_title：Medical physics

authors： Glide-Hurst CK,Duric N,Littrup P

更新日期：2008-09-01 00:00:00

abstract：:Postoperative beta-irradiation after pterygium excision has been considered a valuable therapeutic procedure to reduce the recurrence rate. Recently, it was reported that beta-irradiation also substantially reduced the risk of surgical failure after glaucoma surgery. Pure beta-irradiation using a 90Sr/Y applicator has...

journal_title：Medical physics

authors： Park YK,Ye SJ,Kim IH,Wee WR,Kim MK,Han HS,Son KJ,Park UJ

更新日期：2008-05-01 00:00:00

abstract：:An easy-to-use phantom has been constructed for checking the accuracy of a stereotactic computed tomography localization system. This phantom has been used on a commercially available stereotactic radiosurgery system. With this system, the phantom reference point, whose location is established by means of a precision ...

journal_title：Medical physics

authors： Ekstrand KE,Olds WW,Branch CL

更新日期：1993-03-01 00:00:00

abstract：:The geometric accuracy and precision of an image-guided treatment system were assessed. Image guidance is performed using an x-ray volume imaging (XVI) system integrated with a linear accelerator and treatment planning system. Using an amorphous silicon detector and x-ray tube, volumetric computed tomography images ar...

journal_title：Medical physics

authors： Sharpe MB,Moseley DJ,Purdie TG,Islam M,Siewerdsen JH,Jaffray DA

更新日期：2006-01-01 00:00:00

abstract：PURPOSE:To evaluate the treatment planning system (TPS) performance of the ZAP-X stereotactic radiosurgery (SRS) system through nondosimetric, dosimetric, and end-to-end (E2E) tests. METHODS:A comprehensive set of TPS commissioning and validation tests were developed using published guidelines. Nondosimetric validatio...

journal_title：Medical physics

authors： Srivastava SP,Jani SS,Pinnaduwage DS,Yan X,Rogers L,Barranco FD,Barani IJ,Sorensen S

更新日期：2021-01-28 00:00:00

abstract：PURPOSE:To validate GPUMCD, a new package for fast Monte Carlo dose calculations based on the GPU (graphics processing unit), as a tool for low-energy single seed brachytherapy dosimetry for specific seed models. As the currently accepted method of dose calculation in low-energy brachytherapy computations relies on sev...

journal_title：Medical physics

authors： Hissoiny S,Ozell B,Després P,Carrier JF

更新日期：2011-07-01 00:00:00

abstract：:In a recent paper of Miller et al. (Med. Phys. 43(5), 2141-2152 (2016), the voltage dependence polarity effect of microionization chambers was studied. It was identified that polarity effect arises from the difference in electric potential between the collecting electrode and the guard electrode, which in turn deforms...

journal_title：Medical physics

authors： Brivio D,Sajo E,Zygmanski P

更新日期：2017-03-01 00:00:00

abstract：PURPOSE:The automated segmentation of each lung and trachea in CT scans is commonly taken as a solved problem. Indeed, existing approaches may easily fail in the presence of some abnormalities caused by a disease, trauma, or previous surgery. For robustness, we present ALTIS (implementation is available at http://lids....

journal_title：Medical physics

authors： Sousa AM,Martins SB,Falcão AX,Reis F,Bagatin E,Irion K

更新日期：2019-11-01 00:00:00

abstract：:Fourier transform infrared (FTIR) microspectroscopic imaging and small angle x-ray scattering (SAXS) were combined to investigate the supramolecular structure of collagen from 27 tissue sections from patients undergoing mastectomy, excisional biopsy, or mammoplasty. Both techniques were correlated by matching the scat...

journal_title：Medical physics

authors： Ooi GJ,Fox J,Siu K,Lewis R,Bambery KR,McNaughton D,Wood BR

更新日期：2008-05-01 00:00:00

abstract：:An algorithm, which combines the scanning beam with dynamic collimation to generate any arbitrary intensity profile, is presented. The desired intensity profile is assumed to be piecewise linear. The dynamic collimation method used is the "sliding window." The algorithm can be used either for a given scanning beam pro...

journal_title：Medical physics

authors： Spirou SV,Chui CS

更新日期：1996-01-01 00:00:00

abstract：:Nowadays, digital subtraction angiography systems must be able to sustain real-time acquisition (30 frames per second) of 512 x 512 x 8 bit images and store several sequences of such images on low cost and general-purpose mass memories. Concretely, that means a 7.8 Mbytes per second rate and about 780 Mbytes disk spac...

journal_title：Medical physics

authors： Liénard J

更新日期：1989-11-01 00:00:00

abstract：:We are developing a computer program for automated detection of clustered microcalcifications on mammograms. In this study, we investigated the effectiveness of a signal classifier based on a convolution neural network (CNN) approach for improvement of the accuracy of the detection program. Fifty-two mammograms with c...

journal_title：Medical physics

authors： Chan HP,Lo SC,Sahiner B,Lam KL,Helvie MA

更新日期：1995-10-01 00:00:00

abstract：PURPOSE:The overall goal of this work is to improve the computed tomography (CT) image quality for patients with metal implants or fillings by completing the missing kilovoltage (kV) projection data with selectively acquired megavoltage (MV) data that do not suffer from photon starvation. When both of these imaging sys...

journal_title：Medical physics

authors： Wu M,Keil A,Constantin D,Star-Lack J,Zhu L,Fahrig R

更新日期：2014-12-01 00:00:00

abstract：PURPOSE:The paper presents a complete computer-aided detection (CAD) system for the detection of lung nodules in computed tomography images. A new mixed feature selection and classification methodology is applied for the first time on a difficult medical image analysis problem. METHODS:The CAD system was trained and t...

journal_title：Medical physics

authors： Tan M,Deklerck R,Jansen B,Bister M,Cornelis J

更新日期：2011-10-01 00:00:00