Small SRS photon field profile dosimetry performed using a PinPoint air ion chamber, a diamond detector, a novel silicon-diode array (DOSI), and polymer gel dosimetry. Analysis and intercomparison.

abstract：:Deformable registration is needed for a variety of tasks in establishing the voxel correspondence between respiratory phases. Most registration algorithms assume or imply that the deformation field is smooth and continuous everywhere. However, the lungs are contained within closed invaginated sacs called pleurae and a...

journal_title：Medical physics

authors： Wu Z,Rietzel E,Boldea V,Sarrut D,Sharp GC

更新日期：2008-02-01 00:00:00

abstract：:A prototype Emission-Transmission Computed Tomography (ETCT) system is being developed that will acquire single-slice x-ray transmission CT images simultaneously with single photon emission computed tomography (SPECT) images. This system will permit the correlation of anatomical information from x-ray CT with function...

journal_title：Medical physics

authors： Liew SC,Hasegawa BH

更新日期：1991-09-01 00:00:00

abstract：PURPOSE:Sterile radiation reduction gloves have been widely used in the past decade to provide modest decreases in operator hand dose when the hands are placed in the field of view (FOV). While multiple publications have quantified the potential dose reduction from the use of such gloves, possible effects on the patien...

journal_title：Medical physics

authors： Pasciak A,Neveu M,Sriharan A,Balius A,Jones A

更新日期：2012-06-01 00:00:00

abstract：:Noise power spectrum (NPS) and detective quantum efficiency (DQE) for metal-plate/film portal detectors are reported for the Co-60 and Linac 10 MV spectra. The detectors consist of a double-emulsion portal film secured between plates of aluminum, copper, brass, or lead. The NPS was found to be independent of the detec...

journal_title：Medical physics

authors： Falco T,Fallone BG

更新日期：1998-12-01 00:00:00

abstract：PURPOSE:To use Cone Beam CT scans obtained just prior to treatments of head and neck cancer patients to measure the setup error and cumulative dose uncertainty of the cochlea. METHODS:Data from 10 head and neck patients with 10 planning CTs and 52 Cone Beam CTs taken at time of treatment were used in this study. Patie...

journal_title：Medical physics

authors： Yan M,Lovelock D,Hunt M,Mechalakos J,Hu Y,Pham H,Jackson A

更新日期：2013-12-01 00:00:00

abstract：PURPOSE:The purposes of this study is to measure the low frequency drop (LFD) of the modulation transfer function (MTF), associated with the long tails of the detector point spread function (PSF) of an on-board flat panel imager and study its impact on cone-beam CT (CBCT) image quality and scatter measurement accuracy....

journal_title：Medical physics

authors： Lazos D,Williamson JF

更新日期：2012-09-01 00:00:00

abstract：PURPOSE:In recent years, laser-based acceleration of charged particles has rapidly progressed and medical applications, e.g., in radiotherapy, might become feasible in the coming decade. Requirements are monoenergetic particle beams with long-term stable and reproducible properties as well as sufficient particle intens...

journal_title：Medical physics

authors： Beyreuther E,Enghardt W,Kaluza M,Karsch L,Laschinsky L,Lessmann E,Nicolai M,Pawelke J,Richter C,Sauerbrey R,Schlenvoigt HP,Baumann M

更新日期：2010-04-01 00:00:00

abstract：PURPOSE:Identification of calcifications and hemorrhages is essential for the etiological diagnosis of cerebral lesions. The purpose of this work was to develop a robust method for characterization of para- and diamagnetic intracerebral lesions based on clinical gradient-echo magnetic resonance phase data acquired at 1...

journal_title：Medical physics

authors： Schweser F,Deistung A,Lehr BW,Reichenbach JR

更新日期：2010-10-01 00:00:00

abstract：:The modulation transfer function (MTF) is a commonly used metric for defining the spatial resolution characteristics of imaging systems. While the MTF is defined in terms of how an imaging system demodulates the amplitude of a sinusoidal input, this approach has not been in general use to measure MTFs in the medical i...

journal_title：Medical physics

authors： Boone JM,Yu T,Seibert JA

更新日期：1996-12-01 00:00:00

abstract：PURPOSE:Optoacoustic imaging enables mapping the optical absorption of biological tissue using optical excitation and acoustic detection. Although most image-reconstruction algorithms are based on the assumption of a detector with an isotropic sensitivity, the geometry of the detector often leads to a response with spa...

journal_title：Medical physics

authors： Rosenthal A,Ntziachristos V,Razansky D

更新日期：2011-07-01 00:00:00

abstract：PURPOSE:Different low-signal correction (LSC) methods have been shown to efficiently reduce noise streaks and noise level in CT to provide acceptable images at low-radiation dose levels. These methods usually result in CT images with highly shift-variant and anisotropic spatial resolution and noise, which makes the par...

journal_title：Medical physics

authors： Gomez-Cardona D,Hayes JW,Zhang R,Li K,Cruz-Bastida JP,Chen GH

更新日期：2018-05-01 00:00:00

abstract：PURPOSE:Spirometry exhibits baseline drift and frequent measurement errors so it cannot be used by itself to provide tidal volume-based image sorting or breathing motion modeling. Other breathing surrogates, in this study an abdominal bellows system, are drift free but do not measure tidal volume. Simultaneously using ...

journal_title：Medical physics

authors： Werner R,White B,Handels H,Lu W,Low DA

更新日期：2010-02-01 00:00:00

abstract：:Measurements of a 670-MeV/amu 20Ne beam at the Lawrence Berkeley Laboratory Bevalac heavy-ion accelerator with various thicknesses of water absorber were obtained with the BERKLET. The BERKLET, a simple three-stage solid-state telescope detector, has been described previously. This instrument measures the linear energ...

journal_title：Medical physics

authors： Llacer J,Schmidt JB,Tobias CA

更新日期：1990-03-01 00:00:00

abstract：:An anthropomorphic 1H MRS head phantom has been developed which mimics the in vivo structure, metabolite concentrations, and relaxation times (for both water and metabolites) of human brain tissue. Different brain regions and two tumor types, fluid-containing ventricles, and air-filled sinus, and subcutaneous fat are ...

journal_title：Medical physics

authors： Rice JR,Milbrandt RH,Madsen EL,Frank GR,Boote EJ,Blechinger JC

更新日期：1998-07-01 00:00:00

abstract：:Heat therapies such as hyperthermia and thermoablation are very promising approaches in the treatment of cancer. Compared with available hyperthermia modalities, magnetic fluid hyperthermia (MFH) yields better results in uniform heating of the deeply situated tumors. In this approach, fluid consisting of superparamagn...

journal_title：Medical physics

authors： Tasci TO,Vargel I,Arat A,Guzel E,Korkusuz P,Atalar E

更新日期：2009-05-01 00:00:00

abstract：PURPOSE:To develop and evaluate the impact on lesion conspicuity of a software-based x-ray scatter correction algorithm for digital breast tomosynthesis (DBT) imaging into which a precomputed library of x-ray scatter maps is incorporated. METHODS:A previously developed model of compressed breast shapes undergoing mamm...

journal_title：Medical physics

authors： Feng SS,D'Orsi CJ,Newell MS,Seidel RL,Patel B,Sechopoulos I

更新日期：2014-03-01 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：:Fourier transform infrared (FTIR) microspectroscopic imaging and small angle x-ray scattering (SAXS) were combined to investigate the supramolecular structure of collagen from 27 tissue sections from patients undergoing mastectomy, excisional biopsy, or mammoplasty. Both techniques were correlated by matching the scat...

journal_title：Medical physics

authors： Ooi GJ,Fox J,Siu K,Lewis R,Bambery KR,McNaughton D,Wood BR

更新日期：2008-05-01 00:00:00

abstract：:The nucletron Leipzig applicator is designed for (HDR) 192Ir brachy radiotherapy of surface lesions. The dosimetric characteristics of this applicator were investigated using simulation method based on Monte Carlo N-particle (MCNP) code and phantom measurements. The simulation method was validated by comparing calcula...

journal_title：Medical physics

authors： Niu H,Hsi WC,Chu JC,Kirk MC,Kouwenhoven E

更新日期：2004-12-01 00:00:00

abstract：PURPOSE:There are growing expectations that imaging biomarkers for tumor therapeutic drug response assessment will speed up preclinical testing of anticancer drugs in rodent models. The only imaging biomarker presently approved by the U.S. Food and Drug Administration is tumor size measurement based on either World Hea...

journal_title：Medical physics

authors： Lee YC,Goins BA,Fullerton GD

更新日期：2010-09-01 00:00:00

abstract：:This study compared air exposures during conventional dental and maxillofacial radiography and similar views using free-focus radiography with conventional image receptors. The results show that periapical type surveys on nonscreen film placed extraorally or in the buccal fold may be carried out with an exposure to th...

journal_title：Medical physics

authors： Jensen TW,Randall GJ,Goldberg AJ

更新日期：1980-07-01 00:00:00

abstract：:Many problems in physics involve imaging objects with high spatial frequency content in a limited amount of time. The limitation of available experimental data leads to the infamous problem of diffraction limited data which manifests itself by causing ringing in the image. This ringing is due to the interference pheno...

journal_title：Medical physics

authors： Haacke EM,Liang ZP,Izen SH

更新日期：1989-05-01 00:00:00

abstract：PURPOSE:Radiation treatments are trending toward delivering higher doses per fraction under stereotactic radiosurgery and hypofractionated treatment regimens. There is a need for accurate 3D in vivo patient dose verification using electronic portal imaging device (EPID) measurements. This work presents a model-based te...

journal_title：Medical physics

authors： Van Uytven E,Van Beek T,McCowan PM,Chytyk-Praznik K,Greer PB,McCurdy BM

更新日期：2015-12-01 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：:In this paper we examine the few-view reconstruction problem as it applies to imaging vascular trees. A fully automated reconstruction algorithm is described that circumvents the traditional "correspondence problem," using only notions of consistency and connectivity. It is assumed that the vascular tree is a connecte...

journal_title：Medical physics

authors： Henri CJ,Peters TM

更新日期：1996-02-01 00:00:00

abstract：PURPOSE:The fundamental nature of positron emission tomography (PET), as an event detection system, provides some flexibility for data handling, including retrospective data manipulation. The reorganization of acquisition data allows the emulation of new scans arising from identical radiotracer spatial distributions, b...

journal_title：Medical physics

authors： Schaefferkoetter J,Nai YH,Reilhac A,Townsend DW,Eriksson L,Conti M

更新日期：2019-06-01 00:00:00

abstract：:We compare the results of absorbed dose determined at reference conditions according to the AAPM TG-21 dose calibration protocol and the new AAPM TG-51 protocol. The AAPM TG-21 protocol for absorbed dose calibration is based on ionization chambers having exposure calibration factors for 60Co gamma rays, N(x). The new ...

journal_title：Medical physics

authors： Ding GX,Cygler JE,Kwok CB

更新日期：2000-06-01 00:00:00

abstract：:We have made a comparative investigation of the estimated spectra obtained by the Laplace transform analysis of the transmitted exposure data measured in an absorption study of a 4-MV x-ray beam. Four transform pair models currently used with this method have been evaluated. It has been determined that the Archer-Wagn...

journal_title：Medical physics

authors： Ahuja SD,Steward PG,Roy TS,Slessinger ED

更新日期：1986-05-01 00:00:00

abstract：PURPOSE:To balance dose reduction and image registration accuracy in breast setup imaging. In particular, the authors demonstrate the relationship between scan angle and dose delivery for cone beam tomosynthesis (CBTS) when employed for setup verification of breast cancer patients with surgical clips. METHODS:The dose...

journal_title：Medical physics

authors： Winey BA,Zygmanski P,Cormack RA,Lyatskaya Y

更新日期：2010-08-01 00:00:00

abstract：PURPOSE:It is very important for calculation of clinical indices and diagnosis to detect thyroid nodules from ultrasound images. However, this task is a challenge mainly due to heterogeneous thyroid nodules with distinct components are similar to background in ultrasound images. In this study, we employ cascade deep co...

journal_title：Medical physics

authors： Ma J,Wu F,Jiang T,Zhu J,Kong D

更新日期：2017-05-01 00:00:00