Optical image processing with liquid-crystal display for image intensifier/television systems.

abstract：:Using stable materials capable of mimicking any soft tissues of the human body--quantitatively with respect to speed of sound, density, and attenuation coefficient and semiquantitatively with respect to scatter--we have constructed a torso section phantom containing simulated bowel gas, kidney, kidney fat pad, liver, ...

journal_title：Medical physics

authors： Madsen EL,Zagzebski JA,Ghilardi-Netto T

更新日期：1980-01-01 00:00:00

abstract：PURPOSE:The authors investigate the impact that incremental increases in the level of detail of patient-specific prior information have on image quality and the convergence behavior of an inversion algorithm in the context of near-field microwave breast imaging. A methodology is presented that uses image quality measur...

journal_title：Medical physics

authors： Kurrant D,Baran A,LoVetri J,Fear E

更新日期：2017-12-01 00:00:00

abstract：:Model-based deformable organ registration techniques using the finite element method (FEM) have recently been investigated intensively and applied to image-guided adaptive radiotherapy (IGART). These techniques assume that human organs are linearly elastic material, and their mechanical properties are predetermined. U...

journal_title：Medical physics

authors： Chi Y,Liang J,Yan D

更新日期：2006-02-01 00:00:00

abstract：:Luminance scatter fractions were measured for patients and phantoms in various regions of the chest film. Scatter fractions were found to be highly variable, being quite high in the regions of the chest with a large equivalent tissue thickness (e.g. mediastinum, chest wall, and subdiaphragmatic areas). For example, ap...

journal_title：Medical physics

authors： Niklason LT,Sorenson JA,Nelson JA

更新日期：1981-09-01 00:00:00

abstract：PURPOSE:To improve the efficiency of atlas-based segmentation without compromising accuracy, and to demonstrate the validity of the proposed method on MRI-based prostate segmentation application. METHODS:Accurate and efficient automatic structure segmentation is an important task in medical image processing. Atlas-bas...

journal_title：Medical physics

authors： Xie Q,Ruan D

更新日期：2014-04-01 00:00:00

abstract：:We have developed two prototypes of portable gamma cameras for medical applications based on a previous prototype designed and tested by our group. These cameras use a CsI(Na) continuous scintillation crystal coupled to the new flat-panel-type multianode position-sensitive photomultiplier tube, H8500 from Hamamatsu Ph...

journal_title：Medical physics

authors： Sánchez F,Fernández MM,Giménez M,Benlloch JM,Rodríguez-Alvarez MJ,García de Quirós F,Lerche Ch,Pavón N,Palazón JA,Martínez J,Sebastiá A

更新日期：2006-11-01 00:00:00

abstract：:Anatomy-based positron emission tomography (PET) image enhancement techniques have been shown to have the potential for improving PET image quality. However, these techniques assume an accurate alignment between the anatomical and the functional images, which is not always valid when imaging the chest due to respirato...

journal_title：Medical physics

authors： Qiao F,Pan T,Clark JW Jr,Mawlawi O

更新日期：2007-12-01 00:00:00

abstract：PURPOSE:Two ultra-high-resolution (UHR) computed tomography (CT) scanners are clinically available. One is achieved by a CT system with a 0.25 mm × 160 row detector (Detector-UHR), whereas the other is with a 0.6 mm × 32 row detector with in-plane comb filtering in a dual source CT (Comb-UHR). We compared radiation dos...

journal_title：Medical physics

authors： Kawashima H,Ichikawa K,Takata T,Nagata H,Hoshika M,Akagi N

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:There is significant current interest in the use of biological image guidance in radiotherapy planning. In lung-cancer treatment, tumor motion due to respiration is known to be a limitation. This is particularly true in PET, where image data are collected over a number of minutes. An in-house-developed 4D PET a...

journal_title：Medical physics

authors： Perrin R,Evans PM,Webb S,Partridge M

更新日期：2010-02-01 00:00:00

abstract：PURPOSE:To develop a novel system for patient-specific combined optimization of couch, collimator, and gantry angles for use in volumetric modulated arc therapy (VMAT) treatment planning. The system was designed to produce highly compact dose distributions by extensively sampling the 4π space. Automated fixed couch tra...

journal_title：Medical physics

authors： MacDonald RL,Syme A,Little B,Ward L,Thomas CG

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:To commission and benchmark a vendor-supplied (Varian Medical Systems) Monte Carlo phase-space data for the 6 MV flattening filter free (FFF) energy mode on a TrueBeam linear accelerator for the purpose of quality assurance of clinical volumetric modulated arc therapy (VMAT) treatment plans. A method for render...

journal_title：Medical physics

authors： Gete E,Duzenli C,Milette MP,Mestrovic A,Hyde D,Bergman AM,Teke T

更新日期：2013-02-01 00:00:00

abstract：:This paper compares the characteristics of three types of commercial p-type electron diodes specially designed for in vivo dosimetry (Scanditronix EDD2, Sun Nuclear QED 111200-0 and PTW T60010E diodes coupled with a Therados DPD510 dosimeter) in electron fields with energies from 4.5 to 21 MeV, and in conditions simil...

journal_title：Medical physics

authors： Marre D,Marinello G

更新日期：2004-01-01 00:00:00

abstract：PURPOSE:This study investigated the dosimetry performance of a linear fiber-optic coupled dosimeter with a sensitive element varying from 3 to 15 cm in length. The dosimeter is comprised of a tissue equivalent plastic scintillating fiber coupled to a photomultiplier tube (PMT). The sensitive element has a length repres...

journal_title：Medical physics

authors： Hoerner M,Hintenlang D

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:The combination of nonhuman primates (NHPs) with the state-of-the-art molecular imaging technologies allows for within-subject longitudinal research aiming at gaining new insights into human normal and disease conditions and provides an ideal foundation for future translational studies of new diagnostic tools, ...

journal_title：Medical physics

authors： Xie T,Chen X,Zaidi H

更新日期：2020-09-01 00:00:00

abstract：PURPOSE:Current on-board imaging systems commonly used by modern linear accelerators (LINACs) have a limited field of view (FOV) for a cone-beam CT (CBCT) scan, which is typically less than 50 cm. Consequently, truncation artifacts often occur for large patients. The goal of this work is to investigate a novel method t...

journal_title：Medical physics

authors： Li T,Li X,Yang Y,Heron DE,Huq MS

更新日期：2010-12-01 00:00:00

abstract：:The assessment of differential left and right lung function is important for patients under consideration for lung resection procedures such as single lung transplantation. We developed an automated, knowledge-based segmentation algorithm for purposes of deriving functional information from dynamic computed tomography...

journal_title：Medical physics

authors： Brown MS,Goldin JG,McNitt-Gray MF,Greaser LE,Sapra A,Li KT,Sayre JW,Martin K,Aberle DR

更新日期：2000-03-01 00:00:00

abstract：PURPOSE:This study aims to measure the surface dose on an anthropomorphic phantom for intensity-modulated radiation therapy (IMRT) plans treated in a 1.5 T magnetic resonance (MR)-Linac. Previous studies have used Monte Carlo programs to simulate surface dose and have recognized high surface dose as a potential limitin...

journal_title：Medical physics

authors： Lim-Reinders S,Keller BM,Sahgal A,Chugh B,Kim A

更新日期：2020-07-01 00:00:00

abstract：PURPOSE:Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCT...

journal_title：Medical physics

authors： Moyers MF

更新日期：2014-06-01 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：:Empirical functions that describe primary beam profiles for radiotherapy treatment planning systems generally account for finite source size only on beams unmodified by blocks, wedges, or compensating filters. To incorporate the effects of extended sources on such modified beams and to treat the effect of an extended ...

journal_title：Medical physics

authors： Starkschall G

更新日期：1988-09-01 00:00:00

abstract：PURPOSE:The goal of this work is to propose a new multichannel method correcting for systematic thickness disturbances and to evaluate its precision in relevant radiation dosimetry applications. METHODS:The eigencolor ratio technique is introduced and theoretically developed to provide a method correcting for thicknes...

journal_title：Medical physics

authors： Bouchard H,Billas I,Subie A,Duane S

更新日期：2021-02-01 00:00:00

abstract：PURPOSE:Adding magnetic resonance (MR)-derived information to standard transrectal ultrasound (TRUS) images for guiding prostate biopsy is of substantial clinical interest. A tumor visible on MR images can be projected on ultrasound (US) by using MR-US registration. A common approach is to use surface-based registratio...

journal_title：Medical physics

authors： van de Ven WJ,Hu Y,Barentsz JO,Karssemeijer N,Barratt D,Huisman HJ

更新日期：2015-05-01 00:00:00

abstract：:The goal of this study was to develop a technique to distinguish benign and malignant breast lesions in secondarily digitized mammograms. A set of 51 mammograms (two views/patient) containing lesions of known pathology were evaluated using six different morphological descriptors: circularity, mu R/sigma R (where mu R ...

journal_title：Medical physics

authors： Pohlman S,Powell KA,Obuchowski NA,Chilcote WA,Grundfest-Broniatowski S

更新日期：1996-08-01 00:00:00

abstract：PURPOSE:To perform a comprehensive and systematic comparison of fixed-beam IMRT and volumetric modulated arc therapy (VMAT) patient-specific QA measurements for a common set of geometries using typical measurement methods. METHODS:Fixed-beam IMRT and VMAT plans were constructed for structure set geometries provided by...

journal_title：Medical physics

authors： Mancuso GM,Fontenot JD,Gibbons JP,Parker BC

更新日期：2012-07-01 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：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:Body composition is known to be associated with many diseases including diabetes, cancers, and cardiovascular diseases. In this paper, we developed a fully automatic body tissue decomposition procedure to segment three major compartments that are related to body composition analysis - subcutaneous adipose tissu...

journal_title：Medical physics

authors： Fu Y,Ippolito JE,Ludwig DR,Nizamuddin R,Li HH,Yang D

更新日期：2020-11-01 00:00:00

abstract：PURPOSE:Dual-energy computed tomography and dual-energy cone-beam computed tomography (DE-CBCT) are promising modalities for applications ranging from vascular to breast, renal, hepatic, and musculoskeletal imaging. Accordingly, the optimization of imaging techniques for such applications would benefit significantly fr...

journal_title：Medical physics

authors： Gang GJ,Zbijewski W,Webster Stayman J,Siewerdsen JH

更新日期：2012-08-01 00:00:00

abstract：:We have reexamined the problem of estimating the luminal area of an elliptically shaped coronary artery cross section from two or more radiographic diameter measurements. The expected error is found to be much smaller than the maximum potential error. In the cases of two orthogonal views, closed form expressions have ...

journal_title：Medical physics

authors： Lee PL,Selzer RH

更新日期：1988-07-01 00:00:00

abstract：:Intravascular brachytherapy requires that the dose be specified within millimeters of the source. High dose gradients near brachytherapy sources require that the source-detector distance be accurately known for dosimetry purposes. Solid phantoms can be designed to accommodate these stringent requirements. This study r...

journal_title：Medical physics

authors： Buckley LA,Thomadsen BR,DeWerd LA

更新日期：2001-06-01 00:00:00