abstract：PURPOSE:TransitQA is an innovative method for Tomotherapy transit dosimetry using the on-board detector (OBD). Our previously published model for Tomotherapy treatment plan verification (AirQA) has been enhanced to take into account patient and couch transmission. AirQA estimates the OBD signal during irradiation with ...

journal_title：Medical physics

authors： Pisaturo O,Miéville F,Tercier PA,Allal AS

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:The accuracy and precision of computed tomography (CT) pulmonary ventilation imaging with conventional CT scanners are limited by breathing variations. We propose a method to correct for the effect of breathing variations in CT ventilation imaging based on external respiratory signals acquired throughout a scan...

journal_title：Medical physics

authors： Yamamoto T,Kabus S

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:We have developed a robust tool for performing volumetric and temporal analysis of nodules from respiratory gated four-dimensional (4D) CT. The method could prove useful in IMRT of lung cancer. METHODS:We modified the conventional graph-cuts method by adding an adaptive shape prior as well as motion informatio...

journal_title：Medical physics

authors： Cha J,Farhangi MM,Dunlap N,Amini AA

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:Currently, in clinical practice of intensity-modulated proton therapy (IMPT), the influence of the minimum monitor unit (MU) constraint is taken into account through postprocessing after the optimization is completed. This may degrade the plan quality and plan robustness. This study aims to mitigate the impact ...

journal_title：Medical physics

authors： Shan J,An Y,Bues M,Schild SE,Liu W

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:Experimental dosimetry of high-dose-rate (HDR) 192 Ir brachytherapy (BT) sources is complicated due to high dose and dose-rate gradients, and softening of photon energy spectrum with depth. A single crystal synthetic diamond detector microDiamond (PTW 60019, Freiburg, Germany) has a small active volume, high se...

journal_title：Medical physics

authors： Kaveckyte V,Malusek A,Benmakhlouf H,Alm Carlsson G,Carlsson Tedgren Å

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:To evaluate plan quality of a novel MRI-compatible direction modulated brachytherapy (DMBT) tandem applicator using 192 Ir, 60 Co, and 169 Yb HDR brachytherapy sources, for various cervical cancer high-risk clinical target volumes (CTVHR ). MATERIALS AND METHODS:The novel DMBT tandem applicator has six periphe...

journal_title：Medical physics

authors： Safigholi H,Han DY,Mashouf S,Soliman A,Meigooni AS,Owrangi A,Song WY

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:The authors investigate the impact that incremental increases in the level of detail of patient-specific prior information have on image quality and the convergence behavior of an inversion algorithm in the context of near-field microwave breast imaging. A methodology is presented that uses image quality measur...

journal_title：Medical physics

authors： Kurrant D,Baran A,LoVetri J,Fear E

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:In prostate radiotherapy, dose distribution may be calculated on CT images, while the MRI can be used to enhance soft tissue visualization. Therefore, a registration between MR and CT images could improve the overall treatment planning process, by improving visualization with a demonstrated interobserver deline...

journal_title：Medical physics

authors： Hamdan I,Bert J,Rest CCL,Tasu JP,Boussion N,Valeri A,Dardenne G,Visvikis D

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:Diabetic retinopathy (DR) is one of the most widespread causes of preventable blindness in the world. The most dangerous stage of this condition is proliferative DR (PDR), in which the risk of vision loss is high and treatments are less effective. Fractal features of the retinal vasculature have been previously...

journal_title：Medical physics

authors： Orlando JI,van Keer K,Barbosa Breda J,Manterola HL,Blaschko MB,Clausse A

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:To study the impact of target geometrical and linac operational parameters, such as target material and thickness, electron beam size, repetition rate, and mean current on the ability of the radiotherapy treatment head to deliver high-dose-rate x-ray irradiation in the context of novel linear accelerators capab...

journal_title：Medical physics

authors： Wang J,Trovati S,Borchard PM,Loo BW Jr,Maxim PG,Fahrig R

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:Detailed characterization of changes in vessel size is crucial for the diagnosis and management of a variety of vascular diseases. Because clinical measurement of vessel size is typically dependent on the radiologist's subjective interpretation of the vessel borders, it is often prone to high inter- and intra-u...

journal_title：Medical physics

authors： O'Dell WG,Gormaley AK,Prida DA

更新日期：2017-12-01 00:00:00

abstract：PURPOSE:The purpose of this study was to quantitatively characterize the fundamental aspects of image quality (IQ) associated with different computed tomography (CT) reconstruction algorithms, the resolution, noise texture, noise magnitude per dose, and use those data to devise a methodology to match IQ between differe...

journal_title：Medical physics

authors： Winslow J,Zhang Y,Samei E

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:A joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and ...

journal_title：Medical physics

authors： Ma Y,Vijande J,Ballester F,Tedgren ÅC,Granero D,Haworth A,Mourtada F,Fonseca GP,Zourari K,Papagiannis P,Rivard MJ,Siebert FA,Sloboda RS,Smith R,Chamberland MJP,Thomson RM,Verhaegen F,Beaulieu L

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:To evaluate the feasibility of using an objective computer-aided system to assess bladder cancer stage in CT Urography (CTU). MATERIALS AND METHODS:A dataset consisting of 84 bladder cancer lesions from 76 CTU cases was used to develop the computerized system for bladder cancer staging based on machine learnin...

journal_title：Medical physics

authors： Garapati SS,Hadjiiski L,Cha KH,Chan HP,Caoili EM,Cohan RH,Weizer A,Alva A,Paramagul C,Wei J,Zhou C

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:The purpose of this study was to provide updated radiation dose from diagnostic exams performed for pregnant patients suspected of pulmonary embolism (PE) using the recently developed BREP phantoms of pregnant woman and the fetus. Also to challenge the validity of current recommendations suggest that ventilatio...

journal_title：Medical physics

authors： Rafat Motavalli L,Hoseinian Azghadi E,Miri Hakimabad H,Akhlaghi P

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:Computed tomography (CT) is one of the most used imaging modalities for imaging both symptomatic and asymptomatic patients. However, because of the high demand for lower radiation dose during CT scans, the reconstructed image can suffer from noise and artifacts due to the trade-off between the image quality and...

journal_title：Medical physics

authors： Kim K,El Fakhri G,Li Q

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:To provide results of water calorimetry and ion chamber measurements in high-energy electron beams carried out at the National Research Council Canada (NRC). There are three main aspects to this work: (a) investigation of the behavior of ionization chambers in electron beams of different energies with focus on ...

journal_title：Medical physics

authors： Muir BR,Cojocaru CD,McEwen MR,Ross CK

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:Intraoperative electron radiation therapy (IOERT) involves the delivery of a high radiation dose during tumor resection in a shorter time than other radiation techniques, thus improving local control of tumors. However, a linear accelerator device is needed to produce the beam safely. Mobile linear accelerators...

journal_title：Medical physics

authors： Marinetto E,Victores JG,García-Sevilla M,Muñoz M,Calvo FÁ,Balaguer C,Desco M,Pascau J

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:To design volume-specific breast phantoms from breast CT (bCT) data sets and estimate the associated normalized mean glandular dose coefficients for breast CT using Monte Carlo methods. METHODS:A large cohort of bCT data sets (N = 215) was used to evaluate breast volume into quintiles (plus the top 5%). The av...

journal_title：Medical physics

authors： Hernandez AM,Boone JM

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:The quantification of vessel wall morphology and plaque burden requires vessel segmentation, which is generally performed by manual delineations. The purpose of our work is to develop and evaluate a new 3D model-based approach for carotid artery wall segmentation from dual-sequence MRI. METHODS:The proposed me...

journal_title：Medical physics

authors： Gao S,van 't Klooster R,Kitslaar PH,Coolen BF,van den Berg AM,Smits LP,Shahzad R,Shamonin DP,de Koning PJH,Nederveen AJ,van der Geest RJ

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:The aim of in vivo skin dosimetry was to measure the absorbed dose to the skin during radiotherapy, when treatment planning calculations cannot be relied on. It is of particularly importance in hypo-fractionated stereotactic modalities, where excessive dose can lead to severe skin toxicity. Currently, commercia...

journal_title：Medical physics

authors： Vicoroski N,Espinoza A,Duncan M,Oborn BM,Carolan M,Metcalfe P,Menichelli D,Perevertaylo VL,Lerch MLF,Rosenfeld AB,Petasecca M

更新日期：2017-10-01 00:00:00

abstract：BACKGROUND:Deep learning methods for radiomics/computer-aided diagnosis (CADx) are often prohibited by small datasets, long computation time, and the need for extensive image preprocessing. AIMS:We aim to develop a breast CADx methodology that addresses the aforementioned issues by exploiting the efficiency of pre-tra...

journal_title：Medical physics

authors： Antropova N,Huynh BQ,Giger ML

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:Accurate deformable image registration is necessary for longitudinal studies. The error associated with commercial systems has been evaluated using computed tomography (CT). Several in-house algorithms have been evaluated for use with magnetic resonance imaging (MRI), but there is still relatively little inform...

journal_title：Medical physics

authors： Ger RB,Yang J,Ding Y,Jacobsen MC,Fuller CD,Howell RM,Li H,Jason Stafford R,Zhou S,Court LE

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:To provide a fast computational method, based on the proximal graph solver (POGS) - A convex optimization solver using the alternating direction method of multipliers (ADMM), for calculating an optimal treatment plan in rotating shield brachytherapy (RSBT). RSBT treatment planning has more degrees of freedom th...

journal_title：Medical physics

authors： Cho M,Wu X,Dadkhah H,Yi J,Flynn RT,Kim Y,Xu W

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:The Imaging and Radiation Oncology Core Houston (IROC-H) (formerly the Radiological Physics Center) has reported varying levels of agreement in their anthropomorphic phantom audits. There is reason to believe one source of error in this observed disagreement is the accuracy of the dose calculation algorithms an...

journal_title：Medical physics

authors： Faught AM,Davidson SE,Fontenot J,Kry SF,Etzel C,Ibbott GS,Followill DS

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:This work concerns computed tomography (CT)-based cardiac functional analysis (CFA) with a reduced radiation dose. As CT-CFA requires images over the entire heartbeat, the scans are often performed at 10-20% of the tube current settings that are typically used for coronary CT angiography. A large image noise th...

journal_title：Medical physics

authors： Fung GSK,Ciuffo L,Ashikaga H,Taguchi K

更新日期：2017-09-01 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:Dynamic myocardial perfusion computed tomography (DM-PCT) imaging offers benefits over quantitative assessment of myocardial blood flow (MBF) for diagnosis and risk stratification of coronary artery disease. However, one major drawback of DM-PCT imaging is that a high radiation level is imparted by repeated sca...

journal_title：Medical physics

authors： Bian Z,Zeng D,Zhang Z,Gong C,Tian X,Yan G,Huang J,Guo H,Chen B,Zhang J,Feng Q,Chen W,Ma J

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:The objective of this study is to develop a computational model for simulating 915 MHz microwave ablation (MWA), and verify the simulation predictions of transient temperature profiles against experimental measurements. Due to the limited experimental data characterizing temperature-dependent changes of tissue ...

journal_title：Medical physics

authors： Deshazer G,Hagmann M,Merck D,Sebek J,Moore KB,Prakash P

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Colitis refers to inflammation of the inner lining of the colon that is frequently associated with infection and allergic reactions. In this paper, we propose deep convolutional neural networks methods for lesion-level colitis detection and a support vector machine (SVM) classifier for patient-level colitis dia...

journal_title：Medical physics

authors： Liu J,Wang D,Lu L,Wei Z,Kim L,Turkbey EB,Sahiner B,Petrick NA,Summers RM

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Integrating a linac with a magnetic resonance imager (MRI) will revolutionize the accuracy of external beam radiation treatments. Irradiating in the presence of a strong magnetic field, however, will modify the dose distribution. These dose modifications have been investigated previously, mainly using Monte Car...

journal_title：Medical physics

authors： Ghila A,Steciw S,Fallone BG,Rathee S

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Plastic scintillation detectors are used for dosimetry in small radiation fields with high dose gradients, e.g., provided by β-emitting sources like 106 Ru/106 Rh eye plaques. A drawback is a background signal caused by Cerenkov radiation generated by electrons passing the optical fibers (light guides) of this ...

journal_title：Medical physics

authors： Eichmann M,Thomann B

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Cone beam computed tomography (CBCT) suffers from a large amount of scatter, resulting in severe scatter artifacts in the reconstructions. Recently, a new scatter correction approach, called improved primary modulator scatter estimation (iPMSE), was introduced. That approach utilizes a primary modulator that is...

journal_title：Medical physics

authors： Bier B,Berger M,Maier A,Kachelrieß M,Ritschl L,Müller K,Choi JH,Fahrig R

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:The purpose of this study was to describe and evaluate methods for calculating a megavoltage computed tomography (MVCT)-derived MR hardware attenuation map (μ-map) and dual-energy CT (DECT) for 511 keV photons. METHODS:Phantom measurements were acquired on a whole-body hybrid PET/MRI system, using a four-chann...

journal_title：Medical physics

authors： Patrick JC,Terry Thompson R,So A,Butler J,Faul D,Stodilka RZ,Yartsev S,Prato FS,Gaede S

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:To identify which physical properties of nanoparticles are correlated with the survival fraction of cells exposed in vitro to low-energy protons in combination with nanoparticles. METHODS:The Geant4 simulation toolkit (version 10.3) was used to model nanoparticles of different sizes (5-50 nm) and materials (Ti...

journal_title：Medical physics

authors： Heuskin AC,Gallez B,Feron O,Martinive P,Michiels C,Lucas S

更新日期：2017-08-01 00:00:00

abstract：:Wireless capsule endoscopy (WCE) is a powerful tool for medical screening and diagnosis, where a small capsule is swallowed and moved by means of natural peristalsis and gravity through the human gastrointestinal (GI) tract. The camera-integrated capsule allows for visualization of the small intestine, a region which ...

journal_title：Medical physics

authors： Shamsudhin N,Zverev VI,Keller H,Pane S,Egolf PW,Nelson BJ,Tishin AM

更新日期：2017-08-01 00:00:00

abstract：PURPOSE:The accuracy of a six degree of freedom (6DoF) couch was evaluated using a novel method. METHODS:Cone beam CT (CBCT) images of a 3D phantom (IsoCal) were acquired with different, known combinations of couch pitch and roll angles. Pitch and roll angles between the maximum allowable values of 357 and 3 degrees w...

journal_title：Medical physics

authors： Zhang Q,Driewer J,Wang S,Li S,Zhu X,Zheng D,Cao Y,Zhang J,Jamshidi A,Cox BW,Knisely JPS,Potters L,Klein EE

更新日期：2017-08-01 00:00:00

abstract：:With the recent clinical implementation of real-time MRI-guided x-ray beam therapy (MRXT), attention is turning to the concept of combining real-time MRI guidance with proton beam therapy; MRI-guided proton beam therapy (MRPT). MRI guidance for proton beam therapy is expected to offer a compelling improvement to the c...

journal_title：Medical physics

authors： Oborn BM,Dowdell S,Metcalfe PE,Crozier S,Mohan R,Keall PJ

更新日期：2017-08-01 00:00:00

abstract：PURPOSE:A critical step in adaptive radiotherapy (ART) workflow is deformably registering the simulation CT with the daily or weekly volumetric imaging. Quantifying the deformable image registration accuracy under these circumstances is a complex task due to the lack of known ground-truth landmark correspondences betwe...

journal_title：Medical physics

authors： Neylon J,Min Y,Low DA,Santhanam A

更新日期：2017-08-01 00:00:00

abstract：PURPOSE:Lung cancer is a major cause of cancer deaths, and the 5-year survival rate of stage IV lung cancer patients is only 2%. However, the 5-year survival rate of stage I lung cancer patients significantly increases to 50%. As such, spiral computed tomography (CT) scans are necessary to diagnose high-risk lung cance...

journal_title：Medical physics

authors： Ma J,Zhou Z,Ren Y,Xiong J,Fu L,Wang Q,Zhao J

更新日期：2017-08-01 00:00:00