Image-based iterative compensation of motion artifacts in computed tomography.

abstract：PURPOSE:Automated 3D breast ultrasound (ABUS) has gained interest in breast imaging. Especially for screening women with dense breasts, ABUS appears to be beneficial. However, since the amount of data generated is large, the risk of oversight errors is substantial. Computer aided detection (CADe) may be used as a secon...

journal_title：Medical physics

authors： Tan T,Mordang JJ,van Zelst J,Grivegnée A,Gubern-Mérida A,Melendez J,Mann RM,Zhang W,Platel B,Karssemeijer N

更新日期：2015-04-01 00:00:00

abstract：:The authors report on the imaging capabilities of a mammographic system demonstrator based on GaAs pixel detectors operating in single photon counting (SPC) mode. The system imaging performances have been assessed by means of the transfer functions: The modulation transfer function (MTF), the normalized noise power sp...

journal_title：Medical physics

authors： Amendolia SR,Bisogni MG,Delogu P,Fantacci ME,Paternoster G,Rosso V,Stefanini A

更新日期：2009-04-01 00:00:00

abstract：PURPOSE:To objectively characterize the performance of the gemstone spectral imaging (GSI) mode of GE CT750 HD scanner from a user's perspective. METHODS:A regular scan protocol that approximates the adult abdomen scan protocol frequently used in the authors' institute was selected as the baseline, and a GSI protocol ...

journal_title：Medical physics

authors： Zhang D,Li X,Liu B

更新日期：2011-03-01 00:00:00

abstract：PURPOSE:This work investigates the energy response and dose-response curve determinations for XR-QA2 radiochromic film dosimetry system used for synchrotron radiation work and for quality assurance in diagnostic radiology, in the range of effective energies 18-46.5 keV. METHODS:Pieces of XR-QA2 films were irradiated, ...

journal_title：Medical physics

authors： Di Lillo F,Mettivier G,Sarno A,Tromba G,Tomic N,Devic S,Russo P

更新日期：2016-01-01 00:00:00

abstract：PURPOSE:Total and regional body composition are important indicators of health and mortality risk, but their measurement is usually restricted to controlled environments in clinical settings with expensive and specialized equipment. A method that approaches the accuracy of the current gold standard method, dual-energy ...

journal_title：Medical physics

authors： Tian IY,Ng BK,Wong MC,Kennedy S,Hwaung P,Kelly N,Liu E,Garber AK,Curless B,Heymsfield SB,Shepherd JA

更新日期：2020-12-01 00:00:00

abstract：:Modern linear accelerators contain multiple isocentres, defined by the mechanical motions of gantry, collimator and table. Isocentre localization for these motions has been performed using film and manual evaluations which have difficulty in relating the individual motions. To address these limitations, we have develo...

journal_title：Medical physics

authors： Heaton R,Smale J,Norrlinger B,Wang Y,van Prooijen M,Islam M

更新日期：2008-07-01 00:00:00

abstract：:The relationship between the pixel value and exit dose was investigated for a new commercially available amorphous silicon electronic portal imaging device. The pixel to dose mapping function was established to be linear for detector distances between 116.5 cm to 150 cm from the source, radiation field sizes from 5 x ...

journal_title：Medical physics

authors： Grein EE,Lee R,Luchka K

更新日期：2002-10-01 00:00:00

abstract：:The purpose of this study is to develop a 4D inverse planning strategy capable of controlling the appearance of the implanted fiducial(s) in segmented IMRT fields for cine MV or combined MV/kV image-guided IMRT. This work is focused on enhancing the visibility of the implanted fiducial(s) in 4D IMRT inverse planning, ...

journal_title：Medical physics

authors： Ma Y,Lee L,Keshet O,Keall P,Xing L

更新日期：2009-06-01 00:00:00

abstract：PURPOSE:The purpose of this work was to investigate the use of an experimental complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) for tracking of moving fiducial markers during radiotherapy. METHODS:The APS has an active area of 5.4 × 5.4 cm and maximum full frame read-out rate of 20 frame s(-1),...

journal_title：Medical physics

authors： Osmond JP,Zin HM,Harris EJ,Lupica G,Allinson NM,Evans PM

更新日期：2011-11-01 00:00:00

abstract：:A fully automatic radiophotoluminescent glass rod dosimeter (GRD) system has recently become commercially available. This article discusses the dosimetric properties of the GRD including uniformity and reproducibility of signal, dose linearity, and energy and directional dependence in high-energy photon beams. In addi...

journal_title：Medical physics

authors： Arakia F,Moribe N,Shimonobou T,Yamashita Y

更新日期：2004-07-01 00:00:00

abstract：:Teletherapy with high linear energy transfer radiations (LET), perhaps more than with low LET types, requires careful beam collimation to limit effects to normal structures. Intensity modulated techniques may also hold promise in this regard. Accordingly, a remote computer-controlled, high-resolution multileaf collima...

journal_title：Medical physics

authors： Farr JB,Maughan RL,Yudelev M,Blosser E,Brandon J,Horste T,Forman JD

更新日期：2007-09-01 00:00:00

abstract：:It is shown that in narrow monoenergetic photon beams under conditions of lateral electron disequilibrium, primary absorbed dose P(r) is a simple function of beam radius r: P(r) = P lambda.(1 - e(-gamma.r)), where P lambda is the primary dose in broad beams for which complete lateral electron equilibrium exists, and g...

journal_title：Medical physics

authors： Nizin PS,Chang XS

更新日期：1991-07-01 00:00:00

abstract：:An applicator system for intraoperative radiation therapy has been fabricated which does not require physical docking with the accelerator. A dosimetric study has been completed which documents the properties of this system for a variety of electron beam energies, applicator sizes, collimator settings, both primary an...

journal_title：Medical physics

authors： Nelson CE,Cook R,Rakfal S

更新日期：1989-09-01 00:00:00

abstract：PURPOSE:This paper describes the clinical implementation and medical commissioning of the MedAustron Particle Therapy Accelerator (MAPTA) for non-isocentric scanned proton beam treatments. METHODS:Medical physics involvement during technical commissioning work is presented. Acceptance testing procedures, including adv...

journal_title：Medical physics

authors： Grevillot L,Osorio Moreno J,Letellier V,Dreindl R,Elia A,Fuchs H,Carlino A,Kragl G,Palmans H,Vatnitsky S,Stock M

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:The quality of a treatment plan for stereotactic body radiotherapy (SBRT) depends on an experience of each treatment planner. Therefore, the treatment plans are subjectively determined by comparison of several treatment plans developed by time consuming iterative manners, while considering the benefit to a tumo...

journal_title：Medical physics

authors： Magome T,Arimura H,Shioyama Y,Mizoguchi A,Tokunaga C,Nakamura K,Honda H,Ohki M,Toyofuku F,Hirata H

更新日期：2012-06-01 00:00:00

abstract：:Three types of iterative algorithms, algebraic inverse treatment planning (AITP), simultaneous iterative inverse treatment planning (SIITP), and iterative least-square inverse treatment planning (ILSITP), differentiated according to their updating sequences, were generalized to three dimension with true beam geometry ...

journal_title：Medical physics

authors： Xing L,Hamilton RJ,Spelbring D,Pelizzari CA,Chen GT,Boyer AL

更新日期：1998-10-01 00:00:00

abstract：BACKGROUND:The rapid development and complexity of new x-ray computed tomography (CT) technologies and the need for evidence-based optimization of image quality with respect to radiation and contrast media dose call for an updated approach towards CT performance evaluation. AIMS:This report offers updated testing guid...

journal_title：Medical physics

authors： Samei E,Bakalyar D,Boedeker KL,Brady S,Fan J,Leng S,Myers KJ,Popescu LM,Ramirez Giraldo JC,Ranallo F,Solomon J,Vaishnav J,Wang J

更新日期：2019-11-01 00:00:00

abstract：PURPOSE:To evaluate the energy dependence of Gafchromic EBT3 film for establishing a quality assurance method of bolus electron conformal radiotherapy. METHODS:We irradiated electron beam to EBT3 films, which were set in the water tank. The linear accelerator used was Varian Clinac 21EX. The energy of electron beams w...

journal_title：Medical physics

authors： Inoue T,Sugimoto S,Fukata K,Kurokawa C,Ozawa S,Sasai K

更新日期：2012-06-01 00:00:00

abstract：:In the present investigation, the necessary tests for implementing a quality assurance program for a commercial treatment planning system (TPS), recently installed at Sao Paulo University School of Medicine Clinicas Hospital-Brazil, was established and performed in accordance with the new IAEA publication TRS 430, and...

journal_title：Medical physics

authors： Camargo PR,Rodrigues LN,Furnari L,Rubo RA

更新日期：2007-07-01 00:00:00

abstract：PURPOSE:The purpose of this study was to detect and analyze anomalies between a large number of computed tomography (CT) scanners, tracked over time, utilized to collect human pulmonary CT data for a national multicenter study: chronic obstructive pulmonary disease genetic epidemiology study (COPDGene). METHODS:A cust...

journal_title：Medical physics

authors： Sieren JP,Newell JD,Judy PF,Lynch DA,Chan KS,Guo J,Hoffman EA

更新日期：2012-09-01 00:00:00

abstract：:Due to practical limitations such as inter- and intraleaf transmission, nondivergent leaf end design, and leaf scatter, multileaf collimators (MLCs) are unable to accurately produce the ideal fluence patterns generated by inverse planning systems. Consequently, low dose regions receive substantially more radiation tha...

journal_title：Medical physics

authors： Popple RA,Fiveash JB,Brezovich IA

更新日期：2007-10-01 00:00:00

abstract：PURPOSE:Digital breast tomosynthesis (DBT) is becoming an important part of breast cancer screening and diagnosis. Compared to two-dimensional mammography, tomosynthesis introduces limited three-dimensional (3D) resolution, but maintains high in-plane resolution, low dose, and allows for similar clinical protocols. The...

journal_title：Medical physics

authors： Berggren K,Cederström B,Lundqvist M,Fredenberg E

更新日期：2018-10-01 00:00:00

abstract：:Many new models of 125I seeds are being introduced, mainly due to the increase in prostate seed implants. We have evaluated the SourceTech Medical (STM), model STM1251, 125I seed using thermoluminescent dosimeters (TLDs) in a solid water phantom. TLD cubes, LiF TLD-100, with dimension 1 mm on each edge, were irradiate...

journal_title：Medical physics

authors： Chiu-Tsao ST,Duckworth TL,Hsiung CY,Li Z,Williamson J,Patel NS,Harrison LB

更新日期：2003-07-01 00:00:00

abstract：:Transmission data for 4-MV bremsstrahlung beams have been measured with a combination of lead and aluminum attenuators. From these data, the original energy spectra have been reconstructed using an iterative least-squares technique, previously evaluated by simulation studies. The spectra on the central axis for three ...

journal_title：Medical physics

authors： Huang PH,Kase KR,Bjärngard BE

更新日期：1983-11-01 00:00:00

abstract：:A theoretical model is described for application in ultrasonic tissue characterization using a calibrated 2-D spectrum analysis method. This model relates 2-D spectra computed from ultrasonic backscatter signals to intrinsic physical properties of tissue microstructures, e.g., size, shape, and acoustic impedance. The ...

journal_title：Medical physics

authors： Liu T,Lizzi FL,Ketterling JA,Silverman RH,Kutcher GJ

更新日期：2007-03-01 00:00:00

abstract：:We designed a questionnaire to be filled out by the physicist at the time of planning treatment with the aid of a computer in order to assess what was learned during the course of the planning session. We analyzed the results to gauge the impact of the 70 treatment planning sessions conducted during the one month peri...

journal_title：Medical physics

authors： Doppke KP,Goitein M

更新日期：1988-03-01 00:00:00

abstract：:An improved reconstructed stereoscopic x-ray image display system, based on the principle of binocular parallax, is described. Pulse-synchronized operation of two triode x-ray tubes and one plumbicon TV camera is employed to separate the left and right images for presentation to the two eyes, respectively. The princip...

journal_title：Medical physics

authors： Zhang S,King PH,Pang XD

更新日期：1983-09-01 00:00:00

abstract：PURPOSE:Theoretical models of the detective quantum efficiency (DQE) of x-ray detectors are an important step in new detector development by providing an understanding of performance limitations and benchmarks. Previous cascaded-systems analysis (CSA) models accounted for photoelectric interactions only. This paper des...

journal_title：Medical physics

authors： Yun S,Tanguay J,Kim HK,Cunningham IA

更新日期：2013-04-01 00:00:00

abstract：BACKGROUND:Deep learning methods for radiomics/computer-aided diagnosis (CADx) are often prohibited by small datasets, long computation time, and the need for extensive image preprocessing. AIMS:We aim to develop a breast CADx methodology that addresses the aforementioned issues by exploiting the efficiency of pre-tra...

journal_title：Medical physics

authors： Antropova N,Huynh BQ,Giger ML

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:Intensity-modulated proton therapy (IMPT) is known to be sensitive to patient setup and range uncertainty issues. Multiple robust optimization methods have been developed to mitigate the impact of these uncertainties. Here, we propose a new robust optimization method, which provides an alternative way of robust...

journal_title：Medical physics

authors： Shan J,Sio TT,Liu C,Schild SE,Bues M,Liu W

更新日期：2019-01-01 00:00:00