A novel 3D printing method for accurate anatomy replication in patient-specific phantoms.

abstract：:The bremsstrahlung spectrum from an 8-MeV linear accelerator has been measured using a NaI(T1) spectrometer system. The spectrum shows a low-energy cutoff at 0.4 MeV and the maximum photon energy to be approximately 6% greater than the nominal energy. The maximum emission of energy fluence was 1.6 and 1.8 MeV for meas...

journal_title：Medical physics

authors： Levy LB,Waggener RG,Wright AE

更新日期：1976-05-01 00:00:00

abstract：:Double checking of the monitor units (MU) is an important step in the quality assurance (QA) process in radiosurgery. In this paper we propose the use of an independent algorithm constructed using the ellipsoid which best fits the measurements taken with the bubble head frame. The monitor units calculated by this inde...

journal_title：Medical physics

authors： Ramos LI,Monge RM,Aristu JJ,Moreno LA

更新日期：2008-01-01 00:00:00

abstract：PURPOSE:To develop a new scintillating fiber-based electronic portal imaging device (EPID) with a high quantum efficiency (QE) while preserving an adequate spatial resolution. METHODS:Two prototypes were built: one with a single pixel readout and the other with an active matrix flat-panel imager (AMFPI) for readout. T...

journal_title：Medical physics

authors： Liu J,Xu Y,Teymurazyan A,Papandreou Z,Pang G

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:Positron emission tomography (PET) is an important tool for nuclear medical imaging. It has been widely used in clinical diagnosis, scientific research, and drug testing. PET is a kind of emission computed tomography. Its basic imaging principle is to use the positron annihilation radiation generated by radionu...

journal_title：Medical physics

authors： Zhang W,Gao J,Yang Y,Liang D,Liu X,Zheng H,Hu Z

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:An improvement in tissue assignment for low-dose rate brachytherapy (LDRB) patients using more accurate Monte Carlo (MC) dose calculation was accomplished with a metallic artifact reduction (MAR) method specific to dual-energy computed tomography (DECT). METHODS:The proposed MAR algorithm followed a four-step ...

journal_title：Medical physics

authors： Côté N,Bedwani S,Carrier JF

更新日期：2016-05-01 00:00:00

abstract：:A scintillation dosemeter is calibrated for 90Sr/90Y beta rays from an ophthalmic applicator, using an extrapolation ionization chamber as a reference instrument. The calibration factor for the scintillation dosemeter agrees with that given by the manufacturer of the dosemeter within ca. 2%. The estimated overall unce...

journal_title：Medical physics

authors： Hakanen AT,Sipilä PM,Kosunen A

更新日期：2004-05-01 00:00:00

abstract：:Stereotactic X-ray mammography (SM) and ultrasound (US) guidance are both commonly used for breast biopsy. While SM provides three-dimensional (3D) targeting information and US provides real-time guidance, both have limitations. SM is a long and uncomfortable procedure and the US guided procedure is inherently two dim...

journal_title：Medical physics

authors： Surry KJ,Mills GR,Bevan K,Downey DB,Fenster A

更新日期：2007-11-01 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: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：PURPOSE:This work describes the performance characterization of a cone-beam CT-guided radiosurgery device, the Gamma Knife® Icon™. METHODS:The performance tests have been categorized into: (a) image quality and mechanical integrity; (b) image coregistration fidelity; (c) adaptive treatment delivery quality; (d) high d...

journal_title：Medical physics

authors： Sarfehnia A,Ruschin M,Chugh B,Yeboah C,Becker N,Cho YB,Lee Y

更新日期：2018-06-29 00:00:00

abstract：PURPOSE:In this article, the authors studied the feasibility of estimating regional mechanical properties in cerebral aneurysms, integrating information extracted from imaging and physiological data with generic computational models of the arterial wall behavior. METHODS:A data assimilation framework was developed to ...

journal_title：Medical physics

authors： Balocco S,Camara O,Vivas E,Sola T,Guimaraens L,Gratama van Andel HA,Majoie CB,Pozo JM,Bijnens BH,Frangi AF

更新日期：2010-04-01 00:00:00

abstract：:A fast, geometric beam angle optimization (BAO) algorithm for clinical intensity-modulated radiation therapy (IMRT) was implemented on ten localized prostate cancer patients on the Radiation Therapy Oncology Group (RTOG) 0126 protocol. The BAO algorithm computed the beam intersection volume (BIV) within the rectum and...

journal_title：Medical physics

authors： Potrebko PS,McCurdy BM,Butler JB,El-Gubtan AS,Nugent Z

更新日期：2007-10-01 00:00:00

abstract：:The hybrid algorithms developed recently for the reconstruction of fan-beam images possess computational and noise properties superior to those of the fan-beam filtered backprojection (FFBP) algorithm. However, the hybrid algorithms cannot be applied directly to a halfscan fan-beam sinogram because they require knowle...

journal_title：Medical physics

authors： Pan X

更新日期：2000-09-01 00:00:00

abstract：:To more accurately and precisely delineate a tumor in a 3D PET image, we proposed a novel, semi-automatic, two-stage method by utilizing an adaptive region-growing algorithm and a dual-front active contour model. First, a rough region of interest (ROI) is manually drawn by a radiation oncologist that encloses a tumor....

journal_title：Medical physics

authors： Li H,Thorstad WL,Biehl KJ,Laforest R,Su Y,Shoghi KI,Donnelly ED,Low DA,Lu W

更新日期：2008-08-01 00:00:00

abstract：:Skeletal dosimetry based on microCT images of trabecular bone has recently been introduced to calculate the red bone marrow (RBM) and the bone surface cell (BSC) equivalent doses in human phantoms for external exposure to photons. In order to use the microCT images for skeletal dosimetry, spongiosa voxels in the skele...

journal_title：Medical physics

authors： Kramer R,Khoury HJ,Vieira JW,Robson Brown KA

更新日期：2009-11-01 00:00:00

abstract：PURPOSE:To present EBT2 film verification of treatment planning with the eXtend System, a relocatable frame system for multiple-fraction or serial multiple-session radiosurgery. METHODS:A human head shaped phantom simulated the verification process for fractionated Gamma Knife (GK) treatment. Phantom preparation for e...

journal_title：Medical physics

authors： Gopishankar N,Bisht RK

更新日期：2012-06-01 00:00:00

abstract：:An in vitro radiographic technique which uses saline/iodine displacement has been developed to study the thickness of bone-equivalent and soft-tissue-equivalent materials within atherosclerotic plaques in arterial specimens which have been cut open longitudinally and laid flat. Results concerning the optimization of t...

journal_title：Medical physics

authors： Moreau M,Holdsworth DW,Fenster A

更新日期：1997-01-01 00:00:00

abstract：PURPOSE:To demonstrate the ultra-high resolution capability of a small field-of-view (FOV) solid state x-ray imaging detector based on an EMCCD sensor. METHODS:A micro-solid state x-ray image intensifier (micro-SSXII) was developed to serve as an ultra-high resolution region-of-interest (ROI) imaging detector. It is b...

journal_title：Medical physics

authors： Singh V,Loughran B,Jain A,Sharma P,Bednarek D,Rudin S

更新日期：2012-06-01 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：:The introduction of negative pions into cancer therapy has required the construction of large new proton accelerators together with special magnetic systems to form and direct the pion beam to a patient. A summary is presented of the fundamental properties of pions and of the methods used to study the therapeutic beam...

journal_title：Medical physics

authors： Richman C

更新日期：1981-05-01 00:00:00

abstract：:Projected light fields are used on treatment simulators and teletherapy treatment units to delineate the size and position of the radiation beam. Any discrepancy between these fields will lead to a systematic field placement error, with possibly serious implications with regard to the accuracy of the delivered dose di...

journal_title：Medical physics

authors： Luchka K,Chen D,Shalev S,Gluhchev G,Rajapakshe R

更新日期：1996-07-01 00:00:00

abstract：PURPOSE:The quality of tomographic images is directly affected by the system model being used in image reconstruction. An accurate system matrix is desirable for high-resolution image reconstruction, but it often leads to high computation cost. In this work the authors present a maximum a posteriori reconstruction algo...

journal_title：Medical physics

authors： Fu L,Qi J

更新日期：2010-02-01 00:00:00

abstract：PURPOSE:Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry o...

journal_title：Medical physics

authors： Stevens NT,Steiner SH,Smith IR,MacKay RJ

更新日期：2011-01-01 00:00:00

abstract：PURPOSE:To determine the accuracy and reproducibility of the automatic- setup procedure of a 3D water scanner (3D SCANNER, Sun Nuclear Corp). The procedure automatically aligns the scanner's coordinate system to the Linac coordinate system. A unique off-center detector holder extends the scan range to 630 mm, eliminati...

journal_title：Medical physics

authors： Li J,Lu B,Yan G,Huang Y,Liu C

更新日期：2012-06-01 00:00:00

abstract：:The synchronization of dynamic multileaf collimator (DMLC) response with respiratory motion is critical to ensure the accuracy of DMLC-based four dimensional (4D) radiation delivery. In practice, however, a finite time delay (response time) between the acquisition of tumor position and multileaf collimator response ne...

journal_title：Medical physics

authors： Vedam S,Docef A,Fix M,Murphy M,Keall P

更新日期：2005-06-01 00:00:00

abstract：:Molecular imaging is the direct or indirect noninvasive monitoring and recording of the spatial and temporal distribution of in vivo molecular, genetic, and/or cellular processes for biochemical, biological, diagnostic, or therapeutic applications. Molecular images that indicate the presence of malignancy can be acqui...

journal_title：Medical physics

authors： Munley MT,Kagadis GC,McGee KP,Kirov AS,Jang S,Mutic S,Jeraj R,Xing L,Bourland JD

更新日期：2013-10-01 00:00:00

abstract：PURPOSE:A 3-year project called LABSYNC has been recently funded by the European Commission, with the aim of designing a radiation facility based on a compact light source, i.e., a laboratory-sized commercial synchrotron, capable of accelerating electrons up to 6 or 20 MeV. An accurate spectral description of hard x ra...

journal_title：Medical physics

authors： Marziani M,Taibi A,Di Domenico G,Gambaccini M

更新日期：2009-10-01 00:00:00

abstract：PURPOSE:The spatial and temporal tracking performance of a commercially available 3D optical surface imaging system is evaluated for its potential use in frameless stereotactic radiosurgery head tracking applications. METHODS:Both 3D surface and infrared (IR) marker tracking were performed simultaneously on a head pha...

journal_title：Medical physics

authors： Wiersma RD,Tomarken SL,Grelewicz Z,Belcher AH,Kang H

更新日期：2013-11-01 00:00:00

abstract：PURPOSE:To use machine-learning algorithms and blur measure (BM) operators to automatically detect motion blur in mammograms. Motion blur has been reported to reduce lesion detection performance and mask small abnormalities, resulting in failure to detect them until they reach more advanced stages. Automatic detection ...

journal_title：Medical physics

authors： Kamona N,Loew M

更新日期：2020-04-01 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