Deconvolution techniques for removing the effects of chemical shift in 19F nuclear magnetic resonance imaging of perfluorocarbon compounds.

abstract：:The trend toward conformal techniques in stereotactic radiosurgery necessitates an accurate and practical method for verification of irregular three-dimensional dose distributions. This work presents the design and evaluation of a phantom system facilitating the measurement of conformal dose distributions using one or...

journal_title：Medical physics

authors： Robar JL,Clark BG

更新日期：2000-05-01 00:00:00

abstract：:A conceptual design is presented showing that, by judiciously choosing the beryllium target thickness and the backstop material, improvements can be achieved in dose-rate, skin sparing, and penetration of neutron beams generated by the same proton accelerator. ...

journal_title：Medical physics

authors： Awschalom M,Rosenberg I

更新日期：1980-09-01 00:00:00

abstract：:The purposes of this study are: (i) to design field flattening filters for the Leipzig applicators of 2 and 3 cm of inner diameter with the source traveling parallel to the applicator contact surface, which are accessories of the microSelectron-HDR afterloader (Nucletron, Veenendaal, The Netherlands). These filters, m...

journal_title：Medical physics

authors： Granero D,Pérez-Calatayud J,Gimeno J,Ballester F,Casal E,Crispín V,van der Laarse R

更新日期：2008-02-01 00:00:00

abstract：PURPOSE:In our institute, the MatriXX has been used for IMRT, VMAT and dynamic arc QA. However, the small fields (<3cm) shaped by HDMLC for SRS dynamic arc (DA) present QA measurement issues when using the MatriXX due to its limited resolution (7.6 mm). A recently available portal dosimetry (PD) software tool in Eclips...

journal_title：Medical physics

authors： Luo G,Crass J,Morales M,Ding G

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm. MATERIALS:Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast...

journal_title：Medical physics

authors： Uwano I,Kudo K,Yamashita F,Goodwin J,Higuchi S,Ito K,Harada T,Ogawa A,Sasaki M

更新日期：2014-02-01 00:00:00

abstract：:The contribution of a commercially available diode matrix (MapCHECK, provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo (VMC++) algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation ...

journal_title：Medical physics

authors： Borca VC,Pasquino M,Ozzello F,Tofani S

更新日期：2009-04-01 00:00:00

abstract：PURPOSE:In this abstract, we discuss a biomechanical head and neck model that will be able to represent patient setup variations as well as physiologic changes and subsequently enable dose calculations on the deformed anatomy. METHODS:We selected Multi Pose MRI as the imaging modality to aid in model development and v...

journal_title：Medical physics

authors： Santhanam A,Ennis D,Low D,Kupelian P

更新日期：2012-06-01 00:00:00

abstract：:The BrachySeed model LS-1 is one of the latest in a series of new brachytherapy 125I seeds that have recently become available commercially for interstitial implants. The dosimetric properties of the seed were investigated analytically, experimentally, and by Monte Carlo simulation. Following the AAPM Task Group 43 fo...

journal_title：Medical physics

authors： Chan GH,Prestwich WV

更新日期：2002-02-01 00:00:00

abstract：:Anisotropy of dose distributions around 103Pd, 125I, and 192Ir sources for interstitial brachytherapy was examined. Dose rates around 125I models 6702 and 6711 and 192Ir sources were measured using lithium fluoride thermoluminescence dosimeters (LiF TLDs) in a water-equivalent, solid phantom. From these measured data ...

journal_title：Medical physics

authors： Nath R,Meigooni AS,Muench P,Melillo A

更新日期：1993-09-01 00:00:00

abstract：:A new system of radiation dose mapping based on laser heating of thermoluminescent dosimetric plates (TLDP) has been developed. Application of this technique to intraoperative radiotherapy (IORT) has been investigated. Preliminary results show that TLDP are a possible alternative to radiological films and ionization c...

journal_title：Medical physics

authors： Beteille D,Setzkom R,Prévost H,Dusseau L,Fesquet J,Gasiot J,Muraro S,Delard R,Dubois JB,Ailleres N,Missous O

更新日期：1996-08-01 00:00:00

abstract：:A method to significantly reduce the exposure area product in fluoroscopy using a pre-patient region-of-interest (ROI) attenuator is presented. The attenuator has a thin central region and a gradually increasing thickness away from the center. It is shown that the unwanted brightening artifact caused by the attenuator...

journal_title：Medical physics

authors： Robert N,Komljenovic PT,Rowlands JA

更新日期：2002-05-01 00:00:00

abstract：PURPOSE:To improve the performance of a computer-aided detection (CAD) system for mass detection by using four-view information in screening mammography. METHODS:The authors developed a four-view CAD system that emulates radiologists' reading by using the craniocaudal and mediolateral oblique views of the ipsilateral ...

journal_title：Medical physics

authors： Wei J,Chan HP,Zhou C,Wu YT,Sahiner B,Hadjiiski LM,Roubidoux MA,Helvie MA

更新日期：2011-04-01 00:00:00

abstract：PURPOSE:The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array,...

journal_title：Medical physics

authors： Qian X,Tucker A,Gidcumb E,Shan J,Yang G,Calderon-Colon X,Sultana S,Lu J,Zhou O,Spronk D,Sprenger F,Zhang Y,Kennedy D,Farbizio T,Jing Z

更新日期：2012-04-01 00:00:00

abstract：PURPOSE:The use of an intravenously injected iodinated contrast agent could help increase the sensitivity of digital mammography by adding information on tumor angiogenesis. Two approaches have been made for clinical implementation of contrast-enhanced digital mammography (CEDM), namely, single-energy (SE) and dual-ene...

journal_title：Medical physics

authors： Hill ML,Mainprize JG,Carton AK,Muller S,Ebrahimi M,Jong RA,Dromain C,Yaffe MJ

更新日期：2013-05-01 00:00:00

abstract：:Treatment of cervical cancer often involves intracavitary high dose rate (HDR) brachytherapy. Dose delivered to the bladder and rectum are typically estimated using the ICRU reference points. Dose to the sigmoid and small bowel are not estimated, yet these organs typically exhibit significant complication rates. The o...

journal_title：Medical physics

authors： Lekx-Toniolo KS,Hunter R,Patel M,Voruganti S,Johanson C,Dhamanaskar K,Farrell T

更新日期：2008-07-01 00:00:00

abstract：PURPOSE:This paper presents the application of MAGIC-f gel in a three-dimensional dose distribution measurement and its ability to accurately measure the dose distribution from a tomotherapy unit. METHODS:A prostate intensity-modulated radiation therapy (IMRT) irradiation was simulated in the gel phantom and the treat...

journal_title：Medical physics

authors： Pavoni JF,Pike TL,Snow J,DeWerd L,Baffa O

更新日期：2012-05-01 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：: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：PURPOSE:A new motion-based gated proton therapy for the treatment of orbital tumors using real-time eye-tracking system was designed and evaluated. METHODS:We developed our system by image-pattern matching, using a normalized cross-correlation technique with LabVIEW 8.6 and Vision Assistant 8.6 (National Instruments, ...

journal_title：Medical physics

authors： Shin D,Yoo SH,Moon SH,Yoon M,Lee SB,Park SY

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:Pulmonary magnetic-resonance-imaging (MRI) and x-ray computed-tomography have provided strong evidence of spatially and temporally persistent lung structure-function abnormalities in asthmatics. This has generated a shift in their understanding of lung disease and supports the use of imaging biomarkers as inter...

journal_title：Medical physics

authors： Guo F,Svenningsen S,Eddy RL,Capaldi DPI,Sheikh K,Fenster A,Parraga G

更新日期：2016-06-01 00:00:00

abstract：:Monte Carlo calculations have been made to determine the energy delivered to a phantom by neutrons escaping from the head of a Varian Clinac 35 medical accelerator at an SSD of 1 m. The energy was sorted into two regions: inside and outside a volume defined by a circular beam of area 100 and 600 cm2. For the two beam ...

journal_title：Medical physics

authors： Ing H,Shore RA

更新日期：1982-01-01 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：:A proton beam is extracted from the 200-MeV linear accelerator at the Fermi National Accelerator Laboratory to investigate the efficacy of proton radiography in medical diagnosis. Fluence rates from 2 X 10(3) to 2 X 10(5) protons/cm2s over a 28-cm diameter field are obtained with a full width at half-maximum beam-ener...

journal_title：Medical physics

authors： Curry J,Steward VW

更新日期：1978-05-01 00:00:00

abstract：:A new radiographic patient positioning technique developed for radiosurgery has been analyzed to show the effect of computed tomography (CT) slice thickness on the precision of target localization during treatment. The positioning technique establishes the pose of the patient's anatomy during treatment by comparing tr...

journal_title：Medical physics

authors： Murphy MJ

更新日期：1999-02-01 00:00:00

abstract：PURPOSE:This paper presents the design of a micro-CT guided small animal robotic needle positioning system. In order to simplify the robotic design and maintain a small targeting error, a novel implementation of the remote center of motion is used in the system. The system has been developed with the objective of achie...

journal_title：Medical physics

authors： Bax JS,Waring CS,Sherebrin S,Stapleton S,Hudson TJ,Jaffray DA,Lacefield JC,Fenster A

更新日期：2013-01-01 00:00:00

abstract：PURPOSE:Formation of new blood vessels (angiogenesis) in response to hypoxia is a fundamental event in the process of tumor growth and metastatic dissemination. However, abnormalities in tumor neovasculature often induce increased interstitial pressure (IP) and further reduce oxygenation (pO2) of tumor cells. In radiot...

journal_title：Medical physics

authors： Lagerlöf JH,Kindblom J,Bernhardt P

更新日期：2011-08-01 00:00:00

abstract：PURPOSE:Radiochromic film provides dose measurement at high spatial resolution, but often is not preferred for routine evaluation of patient-specific intensity modulated radiation therapy (IMRT) plans owing to ease-of-use factors. The authors have established an efficient protocol that combines calibration and measurem...

journal_title：Medical physics

authors： Lewis D,Micke A,Yu X,Chan MF

更新日期：2012-10-01 00:00:00

abstract：:Ir-192 wires have been used in low-dose-rate brachytherapy for many years. Commercially available treatment planning systems approximate the dose rate distribution of the straight or curved wires applying the superposition principle using one of the following methods: (i) The wire is modeled as a set of point sources,...

journal_title：Medical physics

authors： van der Laarse R,Granero D,Pérez-Calatayud J,Meigooni AS,Ballester F

更新日期：2008-03-01 00:00:00

abstract：PURPOSE:Tumor motion during radiotherapy can cause a reduction in target dose coverage and an increase in healthy tissue exposure. Tumor motion is not strictly translational and often exhibits complex six degree-of-freedom (6DoF) translational and rotational motion. Although the dosimetric impact of prostate tumor tran...

journal_title：Medical physics

authors： Shi K,Dipuglia A,Booth J,Alnaghy S,Kyme A,Keall P,Nguyen DT

更新日期：2020-12-01 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