Dose planning with comparison to in vivo dosimetry for epithermal neutron irradiation of the dog brain.

abstract：:Over the past decade, computed tomography (CT) theory, techniques and applications have undergone a rapid development. Since CT is so practical and useful, undoubtedly CT technology will continue advancing biomedical and non-biomedical applications. In this outlook article, we share our opinions on the research and de...

journal_title：Medical physics

authors： Wang G,Yu H,De Man B

更新日期：2008-03-01 00:00:00

abstract：:A computed tomography (CT) based system that compensates for patient surface contour and internal tissue inhomogeneity was implemented in our clinic. The compensators are fabricated with a mixture of tin granules and bee's wax. The tin/wax mixture was optimized for tin granule size and tin granule to wax ratio. The na...

journal_title：Medical physics

authors： Jursinic PA,Podgorsak MB,Paliwal BR

更新日期：1994-03-01 00:00:00

abstract：PURPOSE:In CT-guided liver tumor ablation interventions, registration of a preoperative contrast-enhanced CT image to the intraoperative CT image is hypothesized to improve guidance. This is a highly challenging registration task due to differences in patient poses and large deformations, and therefore high registratio...

journal_title：Medical physics

authors： Gunay G,Luu MH,Moelker A,van Walsum T,Klein S

更新日期：2017-07-01 00:00:00

abstract：:Heating rate (HR) patterns in cylindrical structures were studied with inhomogeneous limb phantoms. These phantoms, arm and thigh models consisting of fat, bone, and muscle material, were heated with Clini-Therm L, M, and MS applicators at 915 MHz. The thigh model is 18 cm in diameter with 2.65-cm-thick fat on the out...

journal_title：Medical physics

authors： Chou CK,McDougall JA,Chan KW,Luk KH

更新日期：1991-11-01 00:00:00

abstract：:Several investigators have approximated the scatter component of digital radiographic images by applying a constant weighting factor to a convolved version of the detected image. The scatter approximation is then subtracted from the detected image. When a constant weighting factor is used, the scatter in areas of low ...

journal_title：Medical physics

authors： Naimuddin S,Hasegawa B,Mistretta CA

更新日期：1987-05-01 00:00:00

abstract：PURPOSE:To study if malfunction of a receiver can be detected robustly using the simple ACR SNR measurement approach on a 32-channel head coil. METHODS:Standard ACR T1W images (11slice) were acquired with a commercial 32 channel head coil on a 3T Philips Achieva MR scanner following the ACR recommended setup. Raw data...

journal_title：Medical physics

authors： Peng Q

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:This study introduces a new hybrid ZTE/Dixon MR-based attenuation correction (MRAC) method including bone density estimation for PET/MRI and quantifies the effects of bone attenuation on metastatic lesion uptake in the pelvis. METHODS:Six patients with pelvic lesions were scanned using fluorodeoxyglucose (18F-...

journal_title：Medical physics

authors： Leynes AP,Yang J,Shanbhag DD,Kaushik SS,Seo Y,Hope TA,Wiesinger F,Larson PE

更新日期：2017-03-01 00:00:00

abstract：PURPOSE:Removal of the linear accelerator (linac) flattening filter enables a high rate of dose deposition with reduced treatment time. When used for megavoltage imaging, an unflat beam has reduced primary beam scatter resulting in sharper images. In fluoroscopic imaging mode, the unflat beam has higher photon count pe...

journal_title：Medical physics

authors： Christensen JD,Kirichenko A,Gayou O

更新日期：2013-08-01 00:00:00

abstract：:In intensity modulated radiation treatments (IMRT), the position of the field edges and the modulation within the beam are often achieved with a multileaf collimator (MLC). During the MLC calibration process, due to the finite accuracy of leaf position measurements, a systematic error may be introduced to leaf positio...

journal_title：Medical physics

authors： Parent L,Seco J,Evans PM,Dance DR,Fielding A

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:To demonstrate the feasibility of compressed sensing (CS) to accelerate the acquisition of hyperpolarized (HP) 129 Xe multi-b diffusion MRI for quantitative assessments of lung microstructural morphometry. METHODS:Six healthy subjects and six chronic obstructive pulmonary disease (COPD) subjects underwent HP 1...

journal_title：Medical physics

authors： Zhang H,Xie J,Xiao S,Zhao X,Zhang M,Shi L,Wang K,Wu G,Sun X,Ye C,Zhou X

更新日期：2018-07-01 00:00:00

abstract：:A comprehensive performance testing program is an essential ingredient of high-quality single-photon emission computed tomography (SPECT). Many of the procedures previously published are complicated, time consuming, or require a special testing environment. This Task Group developed a protocol for evaluating SPECT ima...

journal_title：Medical physics

authors： Graham LS,Fahey FH,Madsen MT,van Aswegen A,Yester MV

更新日期：1995-04-01 00:00:00

abstract：PURPOSE:Brachytherapy with 106 Ru/106 Rh plaques offers good outcomes for small-to-medium choroidal melanomas and retinoblastomas. The dose measurement of the plaques is challenging, due to the small range of the emitted beta particles and steep dose gradients involved. The scarce publications on film dosimetry of 106 ...

journal_title：Medical physics

authors： Hermida-López M,Brualla L

更新日期：2018-04-01 00:00:00

abstract：:A micro-angiographic detector was designed and its performance was previously tested to evaluate its feasibility as an improvement over current x-ray detectors for neuro-interventional imaging. The detector was shown to have a modulation transfer function value of about 2% at the Nyquist frequency of 10 cycles/mm and ...

journal_title：Medical physics

authors： Ganguly A,Rudin S,Bednarek DR,Hoffmann KR

更新日期：2003-11-01 00:00:00

abstract：:Head-scatter factors of symmetric square and rectangular fields (field center on the central beam axis) defined by the upper (Y) and lower (X) jaws for 6 and 15 MV photon beams from 2300CD and 600C accelerators (Varian Associates, Inc., Palo Alto, CA) were measured, as well as those for fields shaped by the Y jaws and...

journal_title：Medical physics

authors： Yu MK,Murray B,Sloboda R

更新日期：1995-08-01 00:00:00

abstract：PURPOSE:Dual source CT (DSCT) systems utilize two measurement systems (A) and (B) offset by about 90 degrees. A special challenge in DSCT is cross-scattered radiation, i.e., scattered radiation from x-ray tube (B) detected in detector (A) and vice versa. Cross-scattered radiation can produce artifacts and degrade the c...

journal_title：Medical physics

authors： Petersilka M,Stierstorfer K,Bruder H,Flohr T

更新日期：2010-11-01 00:00:00

abstract：PURPOSE:The purpose of the work is to describe a new algorithm for the automatic detection of implanted radioactive seeds within the prostate. The algorithm is based on the traditional Hough transform. A method of quality assurance is described as well as a quantitative phantom study to determine the accuracy of the al...

journal_title：Medical physics

authors： Holupka EJ,Meskell PM,Burdette EC,Kaplan ID

更新日期：2004-09-01 00:00:00

abstract：PURPOSE:The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD). METHODS:Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and exp...

journal_title：Medical physics

authors： Wang X,Duan J,Du Y,Shen N,He B,Yuan H

更新日期：2013-08-01 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：:Using high-energy photon and electron beams, the response of two solid water parallel-plate chambers is evaluated against a PTW (Physicallsch-Technische Werkstatten) Farmer-type chamber. These two chambers are (1) a Memorial "Holt" chamber which was further modified by this author to take advantage of electrically con...

journal_title：Medical physics

authors： Kubo H

更新日期：1993-03-01 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:Radiosurgery uses small fields and high-radiation doses to treat intra- and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high-dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the hi...

journal_title：Medical physics

authors： Larraga-Gutierrez JM,Garcia-Hernandez D,Garcia-Garduno OA,Galvan de la Cruz OO,Ballesteros-Zebadua P,Esparza-Moreno KP

更新日期：2012-10-01 00:00:00

abstract：PURPOSE:The primary objective of this work is to measure the secondary neutron field produced by an uncollimated proton pencil beam impinging on different tissue-equivalent phantom materials using organic scintillation detectors. Additionally, the Monte Carlo code mcnpx-PoliMi was used to simulate the detector response...

journal_title：Medical physics

authors： Clarke SD,Pryser E,Wieger BM,Pozzi SA,Haelg RA,Bashkirov VA,Schulte RW

更新日期：2016-11-01 00:00:00

abstract：PURPOSE:The authors have previously reported the advantages of high-sensitivity single-photon emission computed tomography (SPECT) systems for imaging structures located deep inside the brain. DaTscan (Isoflupane I-123) is a dopamine transporter (DaT) imaging agent that has shown potential for early detection of Parkin...

journal_title：Medical physics

authors： Park MA,Moore SC,Müller SP,McQuaid SJ,Kijewski MF

更新日期：2013-04-01 00:00:00

abstract：:An instrument for daily beam checks of medical accelerators is described. Using three silicon diodes, the instrument provides information about calibration, beam symmetry, flatness, and energy variation for both photon and electron beams. Operating characteristics of the instrument and the electronic circuit design pe...

journal_title：Medical physics

authors： Lutz WR,Maddox BJ,Kase KR

更新日期：1985-07-01 00:00:00

abstract：PURPOSE:The local depth dose gradient and the displacement correction factor for Farmer-type ionization chambers are quantified for reference dosimetry at shallow depth in single-layer scanned proton fields. METHOD:Integrated radial profiles as a function of depth (IRPDs) measured at three proton therapy centers were ...

journal_title：Medical physics

authors： Palmans H,Medin J,Trnková P,Vatnitsky S

更新日期：2020-12-01 00:00:00

abstract：PURPOSE:The segmentation accuracy of medical images was improved by increasing the number of training samples using a local image warping technique. The performance of the proposed method was evaluated in the segmentation of breast masses, prostate and brain tumors, and lung nodules. METHODS:We propose a simple data a...

journal_title：Medical physics

authors： Liu H,Cao H,Song E,Ma G,Xu X,Jin R,Liu T,Liu L,Liu D,Hung CC

更新日期：2020-12-10 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:To develop a hypothesis-generating framework for automatic extraction of dose-outcome relationships from an in-house, analytic oncology database. METHODS:Dose-volume histograms (DVH) and clinical outcomes have been routinely stored to the authors' database for 684 head and neck cancer patients treated from 200...

journal_title：Medical physics

authors： Robertson SP,Quon H,Kiess AP,Moore JA,Yang W,Cheng Z,Afonso S,Allen M,Richardson M,Choflet A,Sharabi A,McNutt TR

更新日期：2015-07-01 00:00:00

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：:A computationally efficient pseudodynamical filtering setup is established for elasticity imaging (i.e., reconstruction of shear modulus distribution) in soft-tissue organs given statically recorded and partially measured displacement data. Unlike a regularized quasi-Newton method (QNM) that needs inversion of ill-con...

journal_title：Medical physics

authors： Banerjee B,Roy D,Vasu RM

更新日期：2009-08-01 00:00:00