abstract：PURPOSE:To determine the accuracy and test-retest repeatability of fast radiofrequency (RF) transmit measurement approaches used in Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI). Spatial variation in the transmitted RF field introduces bias and increased variance in quantitative DCE-MRI metrics includi...

journal_title：Medical physics

authors： Bliesener Y,Zhong X,Guo Y,Boss M,Bosca R,Laue H,Chung C,Sung K,Nayak KS

更新日期：2019-06-01 00:00:00

abstract：PURPOSE:One of the promising options for motion management in radiation therapy (RT) is the use of LINAC-compatible robotic-arm-mounted ultrasound imaging system due to its high soft tissue contrast, real-time capability, absence of ionizing radiation, and low cost. The purpose of this work is to develop a novel deep l...

journal_title：Medical physics

authors： Huang P,Yu G,Lu H,Liu D,Xing L,Yin Y,Kovalchuk N,Xing L,Li D

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:Two-dimensional antiscatter grids (2DASG) for cone beam computed tomography (CBCT) is a new area of research to reduce scatter intensity, and consequently improve CBCT image quality. One of the challenges in implementation of 2DASGs is their septa shadows that are impinged on the projections. If these artifacts...

journal_title：Medical physics

authors： Alexeev T,Kavanagh B,Miften M,Altunbas C

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:MR-guided radiation therapy (RT) offers unparalleled soft tissue contrast for localization and target tracking. However, MRI distortions may be detrimental to high precision RT. This work characterizes the gradient nonlinearity (GNL) and total distortions over the first year of clinical operation of a 0.35T MR-...

journal_title：Medical physics

authors： Nejad-Davarani SP,Kim JP,Du D,Glide-Hurst C

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:To automatically detect and isolate areas of low and high stiffness temporal stability in shear wave elastography (SWE) image sequences and define their impact in chronic liver disease (CLD) diagnosis improvement by means of clinical examination study and deep learning algorithm employing convolutional neural n...

journal_title：Medical physics

authors： Gatos I,Tsantis S,Spiliopoulos S,Karnabatidis D,Theotokas I,Zoumpoulis P,Loupas T,Hazle JD,Kagadis GC

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:Brachytherapy is a treatment modality which delivers large doses of radiation in a reduced number of visits. Since a small number of large dose-per-fraction is administered in high dose rate brachytherapy, ensuring the right dose is delivered is highly critical. In this work, a scintillation detector is coupled...

journal_title：Medical physics

authors： Tho D,Beaulieu L

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:The purpose of this study was to assess, using an anthropomorphic digital phantom, the accuracy of algorithms in registering precontrast and contrast-enhanced computed tomography (CT) chest images for generation of iodine maps of the pulmonary parenchyma via temporal subtraction. MATERIALS AND METHODS:The XCAT...

journal_title：Medical physics

authors： Grob D,Oostveen L,Rühaak J,Heldmann S,Mohr B,Michielsen K,Dorn S,Prokop M,Kachelrieβ M,Brink M,Sechopoulos I

更新日期：2019-05-01 00:00:00

abstract：PURPOSE:Magnetic particle imaging (MPI) is a relatively new method to image the spatial distribution of magnetic nanoparticle (MNP) tracers administered to the body with high spatial and temporal resolution using an inhomogeneous magnetic field. The spatial information of the MNP's is encoded using a field free point (...

journal_title：Medical physics

authors： Top CB,Güngör A,Ilbey S,Güven HE

更新日期：2019-04-01 00:00:00

abstract：PURPOSE:The collimator monitoring fill factor (CM-FF) introduced by Stelljes et al. (2017) and the FWHM fill factor (FWHM-FF) introduced by Gago-Arias et al. (2012) were determined using the measured photon fluence response functions of various 2D-arrays. The error detection capabilities of 2D-arrays were studied by co...

journal_title：Medical physics

authors： Stelljes TS,Poppinga D,Kretschmer J,Brodbek L,Looe HK,Poppe B

更新日期：2019-04-01 00:00:00

abstract：PURPOSE:The purpose of this work was to generate uncompressed heterogeneous breast phantom models using size-dependent fibroglandular distributions derived from a large cohort of breast CT (bCT) datasets, and to compare differences in normalized glandular dose coefficients for bCT "DgNCT " when the realistic heterogene...

journal_title：Medical physics

authors： Hernandez AM,Becker AE,Boone JM

更新日期：2019-03-01 00:00:00

abstract：PURPOSE:Dynamic 18 F-FDG PET allows quantitative estimation of cerebral glucose metabolism both at the regional and local (voxel) level. Although sensitive to noise and highly computationally expensive, nonlinear least-squares (NLS) optimization stands as the reference approach for the estimation of the kinetic model p...

journal_title：Medical physics

authors： Ben Bouallègue F,Vauchot F,Mariano-Goulart D

更新日期：2019-03-01 00:00:00

abstract：PURPOSE:To investigate energy deposition in glandular tissues of the breast on macro- and microscopic length scales in the context of mammography. METHODS:Multiscale mammography models of breasts are developed, which include segmented, voxelized macroscopic tissue structure as well as nine regions of interest (ROIs) e...

journal_title：Medical physics

authors： Oliver PAK,Thomson RM

更新日期：2019-03-01 00:00:00

abstract：PURPOSE:Quantification of body composition plays an important role in many clinical and research applications. Radiologic imaging techniques such as Dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and computed tomography (CT) imaging make accurate quantification of the body composition possibl...

journal_title：Medical physics

authors： Liu T,Udupa JK,Miao Q,Tong Y,Torigian DA

更新日期：2019-03-01 00:00:00

abstract：PURPOSE:Wide bore CT scanners use extended field-of-view (eFOV) reconstruction algorithms to attempt to recreate tissue truncated due to large patient habitus. Radiation therapy planning systems rely on accurate CT numbers in order to correctly plan and calculate radiation dose. This study looks at the impact of eFOV r...

journal_title：Medical physics

authors： Cheung JP,Shugard E,Mistry N,Pouliot J,Chen J

更新日期：2019-02-01 00:00:00

abstract：PURPOSE:The determination of absorbed dose to water from external beam radiotherapy using radiation detectors is currently rooted in calibration protocols that do not account for modulations encountered in patient-specific deliveries. Detector response in composite clinical fields has not been extensively studied due t...

journal_title：Medical physics

authors： Desai VK,Labby ZE,Hyun MA,DeWerd LA,Culberson WS

更新日期：2019-02-01 00:00:00

abstract：PURPOSE:Accurately predicting outcome (i.e., overall survival (OS) time) for higher grade glioma (HGG) has great clinical value and would provide optimized guidelines for treatment planning. Radiomics focuses on revealing underlying pathophysiological information in biomedical images for disease analysis and demonstrat...

journal_title：Medical physics

authors： Wu G,Shi Z,Chen Y,Wang Y,Yu J,Lv X,Chen L,Ju X,Chen Z

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:Intensity-modulated proton therapy (IMPT) is known to be sensitive to patient setup and range uncertainty issues. Multiple robust optimization methods have been developed to mitigate the impact of these uncertainties. Here, we propose a new robust optimization method, which provides an alternative way of robust...

journal_title：Medical physics

authors： Shan J,Sio TT,Liu C,Schild SE,Bues M,Liu W

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:It is important to enhance image quality for low-dose CT acquisitions to push the ALARA boundary. Current state-of-the-art block-matching three-dimensional (BM3D) denoising scheme assumes white Gaussian noise (WGN) model. This study proposes a novel filtering module to be incorporated into the BM3D framework fo...

journal_title：Medical physics

authors： Zhao T,Hoffman J,McNitt-Gray M,Ruan D

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:A dynamic bowtie filter can modulate flux along both fan and view angles for reduced patient dose, scatter, and required photon flux, which is especially important for photon counting detectors (PCDs). Among the proposed dynamic bowtie designs, the piecewise-linear attenuator (Hsieh and Pelc, Med Phys. 2013;40:...

journal_title：Medical physics

authors： Shunhavanich P,Hsieh SS,Pelc NJ

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:To develop an automated treatment planning strategy for external beam intensity-modulated radiation therapy (IMRT), including a deep learning-based three-dimensional (3D) dose prediction and a dose distribution-based plan generation algorithm. METHODS AND MATERIALS:A residual neural network-based deep learning...

journal_title：Medical physics

authors： Fan J,Wang J,Chen Z,Hu C,Zhang Z,Hu W

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:The efficiency of radioembolization procedures could be greatly enhanced if results of the 99m Tc-MAA pretreatment procedure were immediately available in the interventional suite, enabling 1-day procedures as a result of direct estimation of the hepatic radiation dose and lung shunt fraction. This would, howev...

journal_title：Medical physics

authors： van der Velden S,Dietze MMA,Viergever MA,de Jong HWAM

更新日期：2019-01-01 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：PURPOSE:At our institution, all proton patient plans undergo patient-specific quality assurance (PSQA) prior to treatment delivery. For intensity-modulated proton beam therapy, quality assurance is complex and time consuming, and it may involve multiple measurements per field. We reviewed our PSQA workflow and identifi...

journal_title：Medical physics

authors： Hernandez Morales D,Shan J,Liu W,Augustine KE,Bues M,Davis MJ,Fatyga M,Johnson JE,Mundy DW,Shen J,Younkin JE,Stoker JB

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:The Alvarez-Macovski method extracts the x-ray energy-dependent information by expanding the attenuation coefficient as a linear combination of functions of energy multiplied by basis set coefficients. Since the basis functions are known a priori, the coefficients represent all the energy-dependent information....

journal_title：Medical physics

authors： Alvarez RE

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:To experimentally commission a dual-energy CT (DECT) joint statistical image reconstruction (JSIR) method, which is built on a linear basis vector model (BVM) of material characterization, for proton stopping power ratio (SPR) estimation. METHODS:The JSIR-BVM method builds on the relationship between the energ...

journal_title：Medical physics

authors： Zhang S,Han D,Williamson JF,Zhao T,Politte DG,Whiting BR,O'Sullivan JA

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:This study developed and validated a Motion Artifact Quantification algorithm to automatically quantify the severity of motion artifacts on coronary computed tomography angiography (CCTA) images. The algorithm was then used to develop a Motion IQ Decision method to automatically identify whether a CCTA dataset ...

journal_title：Medical physics

authors： Ma H,Gros E,Baginski SG,Laste ZR,Kulkarni NM,Okerlund D,Schmidt TG

更新日期：2018-12-01 00:00:00

abstract：PURPOSE:The treatment of moving targets with scanned proton beams is challenging. For motion mitigation, an Active Breathing Coordinator (ABC) can be used to assist breath-holding. The delivery of pencil beam scanning fields often exceeds feasible breath-hold durations, requiring high breath-hold reproducibility. We ev...

journal_title：Medical physics

authors： den Otter LA,Kaza E,Kierkels RGJ,Meijers A,Ubbels FJF,Leach MO,Collins DJ,Langendijk JA,Knopf AC

更新日期：2018-12-01 00:00:00

abstract：PURPOSE:Monte Carlo (MC) dose calculation is generally superior to analytical dose calculation (ADC) used in commercial TPS to model the dose distribution especially for heterogeneous sites, such as lung and head/neck patients. The purpose of this study was to provide a validated, fast, and open-source MC code, MCsquar...

journal_title：Medical physics

authors： Huang S,Souris K,Li S,Kang M,Barragan Montero AM,Janssens G,Lin A,Garver E,Ainsley C,Taylor P,Xiao Y,Lin L

更新日期：2018-12-01 00:00:00

abstract：PURPOSE:The purpose of this paper was to present a method of determining the dose profile of the beam bow-tie filter (BTF) without the need for fixing the x ray tube in a position or using special instruments or dosimeters other than the ordinary types of ion chambers used for CT dosimetry (e.g., Farmer chamber). METH...

journal_title：Medical physics

authors： Al-Senan R

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:The presence of respiratory motion during radiation treatment leads to degradation of the expected dose distribution, both for target coverage and healthy tissue sparing, particularly for techniques like pencil beam scanning proton therapy which have dynamic delivery systems. While tools exist to estimate this ...

journal_title：Medical physics

authors： Pepin MD,Tryggestad E,Wan Chan Tseung HS,Johnson JE,Herman MG,Beltran C

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:Traditionally, unidirectional leaf-sweeping schemes have been employed to deliver IMRT plans using the dynamic multileaf collimator (DMLC) technique. The goal of this research is to investigate the potential impact of relaxing the leaf-motion restrictions in DMLC IMRT on the beam-modulation quality and the deli...

journal_title：Medical physics

authors： Mirzapour SA,Salari E

更新日期：2018-11-01 00:00:00

abstract：:Cardiac arrhythmias are a major health burden, associated with reduced quality of life and substantial morbidity and mortality. Current therapy includes moderately effective medication and catheter-based ablation of arrhythmogenic substrates in the heart. Catheter interventions frequently have to be repeated due to re...

journal_title：Medical physics

authors： Graeff C,Bert C

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:This report describes upgrades and performance characterization of an experimental benchtop cone-beam x-ray fluorescence computed tomography (XFCT) system capable of determining the spatial distribution and concentration of metal probes such as gold nanoparticles (GNPs). Specifically, a high-power (~3 kW) indus...

journal_title：Medical physics

authors： Manohar N,Reynoso FJ,Cho SH

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:Digital breast tomosynthesis (DBT) is becoming an important part of breast cancer screening and diagnosis. Compared to two-dimensional mammography, tomosynthesis introduces limited three-dimensional (3D) resolution, but maintains high in-plane resolution, low dose, and allows for similar clinical protocols. The...

journal_title：Medical physics

authors： Berggren K,Cederström B,Lundqvist M,Fredenberg E

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:An electrically floating radio frequency (RF) shielded PET insert with individual PET detectors shielded by separate Faraday cages enables the MRI built-in body RF coil to be used at least as an RF transmitter, in which the RF field penetrates the imaging region inside the PET ring through the narrow gaps betwe...

journal_title：Medical physics

authors： Akram MSH,Levin CS,Obata T,Hirumi G,Yamaya T

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:A novel 3D printing method has been developed, which employs human CT images to construct patient specific phantoms by controlling the filament extrusion rate. METHODS:An in-house software was developed comprising pixel-by-pixel (PbP) reading of the Hounsfield Units (HU) values in the original patient DICOM im...

journal_title：Medical physics

authors： Okkalidis N

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:The ability to monitor intrafractional tumor motion is essential for radiation therapy of thoracic and abdominal tumors. This study aims to develop a method to track lung tumor motion using intrafractional continuous ultrasound (US) and periodic cone-beam projection images (CBPI). METHODS:Time-sequenced b-mode...

journal_title：Medical physics

authors： Mostafaei F,Tai A,Gore E,Johnstone C,Haase W,Ehlers C,Cooper DT,Lachaine M,Li XA

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:Photon counting arrays (PCAs), capable of measuring the spectral information of individual x-ray photons and recording that information digitally, provide a number of advantages compared to conventional, energy-integrating active matrix flat-panel imagers - such as reducing the undesirable effects of electronic...

journal_title：Medical physics

authors： Liang AK,Koniczek M,Antonuk LE,El-Mohri Y,Zhao Q

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:To investigate whether building a knowledge-based planning (KBP) model with prostate bed plans constructed from constrained hierarchical optimization (CHO) would result in more efficient model construction with more consistent output than a model built using plans from a traditional, trial-and-error-based optim...

journal_title：Medical physics

authors： Lin YH,Hong LX,Hunt MA,Berry SL

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:To develop a deformable mapping technique to match corresponding lesions between digital breast tomosynthesis (DBT) and automated breast ultrasound (ABUS) images. METHODS:External fiducial markers were attached to the surface of two CIRS multi-modality compressible breast phantoms (A and B) containing multiple...

journal_title：Medical physics

authors： Green CA,Goodsitt MM,Brock KK,Davis CL,Larson ED,Lau JH,Carson PL

更新日期：2018-10-01 00:00:00