An inexpensive kVp penetrameter.

abstract：PURPOSE:Dual-energy computed tomography and dual-energy cone-beam computed tomography (DE-CBCT) are promising modalities for applications ranging from vascular to breast, renal, hepatic, and musculoskeletal imaging. Accordingly, the optimization of imaging techniques for such applications would benefit significantly fr...

journal_title：Medical physics

authors： Gang GJ,Zbijewski W,Webster Stayman J,Siewerdsen JH

更新日期：2012-08-01 00:00:00

abstract：PURPOSE:The goal of this work is to propose a new multichannel method correcting for systematic thickness disturbances and to evaluate its precision in relevant radiation dosimetry applications. METHODS:The eigencolor ratio technique is introduced and theoretically developed to provide a method correcting for thicknes...

journal_title：Medical physics

authors： Bouchard H,Billas I,Subie A,Duane S

更新日期：2021-02-01 00:00:00

abstract：:An analytic expression is derived for the transmission of isotropic scattered radiation incident upon an ideal parallel grid. It is found that the expression for the transmission usually found in the literature overestimates the transmission by approximately a factor of two. ...

journal_title：Medical physics

authors： Siddon RL

更新日期：1981-11-01 00:00:00

abstract：PURPOSE:The automated correct segmentation of left and right lungs is a nontrivial problem, because the tissue layer between both lungs can be quite thin. In the case of lung segmentation with left and right lung models, overlapping segmentations can occur. In this paper, the authors address this issue and propose a so...

journal_title：Medical physics

authors： Gill G,Bauer C,Beichel RR

更新日期：2014-10-01 00:00:00

abstract：PURPOSE:There are currently several commercially available radiotherapy treatment units without a flattening filter in the beam line. Unflattened photon beams have an energy and lateral fluence distribution that is different from conventional beams and, thus, their attenuation properties differ. As a consequence, for f...

journal_title：Medical physics

authors： Dalaryd M,Knöös T,Ceberg C

更新日期：2014-11-01 00:00:00

abstract：:The purpose of this study was to quantify in-stent restenoses with 3D B mode and power Doppler ultrasound (U.S.) imaging. In-stent restenoses were mimicked with vascular phantoms in which a nonferromagnetic prototype stent (Boston Scientific) and a ferromagnetic clinical stainless steel stent (Palmaz P295) were embedd...

journal_title：Medical physics

authors： Lécart M,Cardinal MH,Qin Z,Soulez G,Cloutier G

更新日期：2009-02-01 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：PURPOSE:It is estimated that 7% of women in the western world will develop palpable breast cysts in their lifetime. Even though cysts have been correlated with risk of developing breast cancer, many of them are benign and do not require follow-up. We develop a method to discriminate benign solitary cysts from malignant...

journal_title：Medical physics

authors： Kooi T,van Ginneken B,Karssemeijer N,den Heeten A

更新日期：2017-03-01 00:00:00

abstract：PURPOSE:Developed herein is a three-dimensional (3D) flow contrast imaging system leveraging advancements in the extension of laser speckle contrast imaging theories to deep tissues along with our recently developed finite-element diffuse correlation tomography (DCT) reconstruction scheme. This technique, termed speckl...

journal_title：Medical physics

authors： Huang C,Irwin D,Lin Y,Shang Y,He L,Kong W,Luo J,Yu G

更新日期：2015-07-01 00:00:00

abstract：PURPOSE:To evaluate two deformable image registration (DIR) algorithms for the purpose of contour mapping to support image guided adaptive radiotherapy (IGART) with 4D cone beam CT (4DCBCT). METHODS:Eleven locally advanced non-small cell lung cancer (NSCLC) patients underwent one planning 4D fan- beam CT (4DFBCT) and ...

journal_title：Medical physics

authors： Balik S,Hugo G,Weiss E,Jan N,Roman N,Sleeman W,Fatyga M,Christensen G,Murphy M,Lu J,Keall P,Williamson J

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Manual delineation of head and neck (H&N) organ-at-risk (OAR) structures for radiation therapy planning is time consuming and highly variable. Therefore, we developed a dynamic multiatlas selection-based approach for fast and reproducible segmentation. METHODS:Our approach dynamically selects and weights the a...

journal_title：Medical physics

authors： Haq R,Berry SL,Deasy JO,Hunt M,Veeraraghavan H

更新日期：2019-12-01 00:00:00

abstract：:An optimization analysis of digital fluoroscopy has been carried out using (signal/noise)2/dose as a figure of merit. Three signal detection tasks have been considered: (i) small iodine-containing blood vessels; (ii) regions of fat; and (iii) microcalcifications. The effects of x-ray beam filtration and kilovoltage on...

journal_title：Medical physics

authors： Zamenhof RG

更新日期：1982-09-01 00:00:00

abstract：PURPOSE:Intensity modulated proton therapy (IMPT) of head and neck (H&N) cancer patients may be improved by plan adaptation. The decision to adapt the treatment plan based on a dose recalculation on the current anatomy requires a diagnostic quality computed tomography (CT) scan of the patient. As gantry-mounted cone be...

journal_title：Medical physics

authors： Landry G,Nijhuis R,Dedes G,Handrack J,Thieke C,Janssens G,Orban de Xivry J,Reiner M,Kamp F,Wilkens JJ,Paganelli C,Riboldi M,Baroni G,Ganswindt U,Belka C,Parodi K

更新日期：2015-03-01 00:00:00

abstract：:An important aspect of heavy charged particle radiotherapy is its ability to localize dose to the target volume. Current techniques generally employ beam delivery schemes which use range modulated beams in which the Bragg peak is spread out over a range of depths. The range modulation is constant over the entire beam ...

journal_title：Medical physics

authors： Goitein M,Chen GT

更新日期：1983-11-01 00:00:00

abstract：:A number of relocatable head fixation systems have become commercially available or developed in-house to perform fractionated stereotactic radiotherapy (SRT) treatment. The uncertainty usually quoted for the target repositioning in SRT is over 2 mm, more than twice that of stereotactic radiosurgery (SRS) systems. Thi...

journal_title：Medical physics

authors： Zavgorodni SF

更新日期：2000-04-01 00:00:00

abstract：PURPOSE:The purpose of this study is to estimate the effect of edema, developed during implant procedure, on tumor cell surviving fraction(SF) and tumor control probability(TCP) in the patients of prostate cancer who underwent 131 Cs permanent seed implants. METHODS:The impact of edema on SF and TCP, was calculated us...

journal_title：Medical physics

authors： Kehwar TS,Huq MS,Smith RP

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:This article presents a computer-aided diagnosis technique for improving the accuracy of the early diagnosis of Alzheimer's disease (AD). Two hundred and ten 18F-FDG PET images from the ADNI initiative [52 normal controls (NC), 114 mild cognitive impairment (MCI), and 53 AD subjects] are studied. METHODS:The p...

journal_title：Medical physics

authors： Salas-Gonzalez D,Górriz JM,Ramírez J,Illán IA,López M,Segovia F,Chaves R,Padilla P,Puntonet CG

更新日期：2010-11-01 00:00:00

abstract：PURPOSE:The present study was conducted to investigate salivary iodine kinetics and dosimetry during repeated courses of radioiodine ((131)I) therapy for differentiated thyroid cancer (DTC). Such data could provide a better understanding of the mechanisms of (131)I induced salivary toxicity and help to develop appropri...

journal_title：Medical physics

authors： Liu B,Huang R,Kuang A,Zhao Z,Zeng Y,Wang J,Tian R

更新日期：2011-10-01 00:00:00

abstract：PURPOSE:The main objective of this work was to design a comprehensive dosimetry package that would keep all aspects of internal dose calculation within the framework of a single software environment and that would be applicable for a variety of dose calculation approaches. METHODS:Our MATLAB-based graphical user inter...

journal_title：Medical physics

authors： Grimes J,Uribe C,Celler A

更新日期：2013-07-01 00:00:00

abstract：PURPOSE:The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process...

journal_title：Medical physics

authors： Amit G,Purdie TG,Levinshtein A,Hope AJ,Lindsay P,Marshall A,Jaffray DA,Pekar V

更新日期：2015-04-01 00:00:00

abstract：:It is known that motion of an object imaged by magnetic resonance imaging leads to errors and artifacts in the image. This effect is especially important when a pulse sequence with long echo time (TE) and long TR is used to provide T2-weighted images. We have modified the usual spin warp imaging pulse sequence in a wa...

journal_title：Medical physics

authors： Joseph PM,Shetty A,Bonaroti EA

更新日期：1987-07-01 00:00:00

abstract：PURPOSE:Pulse pileup occurring at high x-ray fluxes can severely degrade the energy resolution provided by a photon counting detector, which can represent a problem in spectroscopic CT when performing quantitative material discrimination tasks. As the effects of pileup can be most easily seen as a degradation of a dete...

journal_title：Medical physics

authors： Rink K,Oelfke U,Fiederle M,Zuber M,Koenig T

更新日期：2013-10-01 00:00:00

abstract：PURPOSE:To track variations in the deformation of the arterial wall noninvasively by estimating the accumulated displacement and strain over a cardiac cycle may provide useful indicators of vascular health. METHODS:In this paper, we propose an approach to track a region of interest (ROI) locally and estimate arterial ...

journal_title：Medical physics

authors： Ge W,Krueger CG,Weichmann A,Shanmuganayagam D,Varghese T

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:Imaging the knee under realistic load-bearing conditions can be carried out in a horizontal plane using a C-arm CT scanner. Human subjects can be scanned in a standing position and acquired data successfully reconstructed. However, reconstructing this data is a challenge due to significant artifacts that are in...

journal_title：Medical physics

authors： Choi JH,Keil A,Maier A,Pal S,McWalter EJ,Fahrig R

更新日期：2012-06-01 00:00:00

abstract：:Determination of the relaxation times T1 and T2 which are important for tissue characterization generally requires the use of different pulse sequences in magnetic resonance imaging. In this study, a new pulse sequence which facilitates simultaneous determination of the T1 and T2 times is presented. Determination take...

journal_title：Medical physics

authors： Graumann R,Fischer H,Oppelt A

更新日期：1986-09-01 00:00:00

abstract：PURPOSE:To investigate how the setting of optimization parameters, fractional dose and tuning structure in tomotherapy treatment planning affects plan dosimetric quality and treatment efficiency. METHODS:A digital phantom to simulate head and neck radiotherapy was constructed for this study. Tumor was 10cm long C-shap...

journal_title：Medical physics

authors： Lian J,Burkhardt K,Chera B,Chang S

更新日期：2012-06-01 00:00:00

abstract：:The objective is to understand the differences in the lesion formation processes between microwave and high-intensity focused ultrasound (HIFU) ablation. The lesions formed by microwaves and HIFU were real-time monitored and compared using transparent tissue-mimicking phantoms at 60 and 70 W of driving electrical powe...

journal_title：Medical physics

authors： Chen WS,Wu CC,Fang HY,Liu HL

更新日期：2006-05-01 00:00:00

abstract：PURPOSE:As radiation therapy evolves toward more adaptive techniques, image guidance plays an increasingly important role, not only in patient setup but also in monitoring the delivered dose and adapting the treatment to patient changes. This study aimed to validate a method for evaluation of delivered intensity modula...

journal_title：Medical physics

authors： Moteabbed M,Sharp GC,Wang Y,Trofimov A,Efstathiou JA,Lu HM

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:Both spatial and biological information are necessary in order to perform true optimization of a treatment plan and for predicting clinical outcome. The goal of this work is to develop an enhanced treatment plan evaluation tool which incorporates biological parameters and retains spatial dose information. METH...

journal_title：Medical physics

authors： Zhao B,Joiner MC,Orton CG,Burmeister J

更新日期：2010-11-01 00:00:00

abstract：PURPOSE:Signal encoding in magnetic particle imaging (MPI) is achieved by moving a field-free point (FFP) through the region of interest. One way to increase the sensitivity of the method is to scan the region of interest with a field-free line (FFL) instead of the FFP. Recently, the first feasible FFL coil setup was i...

journal_title：Medical physics

authors： Knopp T,Erbe M,Biederer S,Sattel TF,Buzug TM

更新日期：2010-07-01 00:00:00