The impact of calibration phantom errors on dual-energy digital mammography.

abstract：:We give an overview of the role of Physics in Medicine and Biology in the development of tomographic reconstruction algorithms. We focus on imaging modalities involving ionizing radiation, CT, PET and SPECT, and cover a wide spectrum of reconstruction problems, starting with classical 2D tomography in the 1970s up to ...

journal_title：Physics in medicine and biology

authors： Defrise M,Gullberg GT

更新日期：2006-07-07 00:00:00

abstract：:Simultaneous thermoradiotherapy has been shown to maximize the effect of hyperthermia as a radiation sensitizer in cancer treatment. Here we follow our previous work on feasibility of thermoradiotherapy with the scanning ultrasound reflector linear array system (SURLAS) and TomoTherapy HiArt treatment system, and inve...

journal_title：Physics in medicine and biology

authors： Novák P,Peñagarícano JA,Nahirnyak V,Corry P,Moros EG

更新日期：2008-05-21 00:00:00

abstract：:Computer tomographic (CT) scans are used to correct for tissue inhomogeneities in radiotherapy treatment planning. In order to guarantee a precise treatment, it is important to obtain the relationship between CT Hounsfield units and electron densities (or proton stopping powers for proton radiotherapy), which is the b...

journal_title：Physics in medicine and biology

authors： Schneider U,Pedroni E,Lomax A

更新日期：1996-01-01 00:00:00

abstract：:Magnetic resonance imaging (MRI) may be used to image three-dimensional dose distributions of ionizing radiation in tissue equivalent gels infused with ferrous sulphate solutions, commonly known as Fricke gels. In this technique, ferrous (Fe2+) ions are oxidized to ferric (Fe3+) ions by free radicals produced by ioniz...

journal_title：Physics in medicine and biology

authors： Harris PJ,Piercy A,Baldock C

更新日期：1996-09-01 00:00:00

abstract：:The incorporation of accurately aligned anatomical information as a prior to guide reconstruction and noise regularization in positron emission tomography (PET) has been suggested in many previous studies. However, the advantages of this approach can only be realized if the exact lesion outline is also available. In p...

journal_title：Physics in medicine and biology

authors： Chan C,Fulton R,Feng DD,Meikle S

更新日期：2009-12-21 00:00:00

abstract：:Radiotherapy treatment planning is associated with uncertainties. Examples are uncertainties in the tumour location due to organ movement or the inter/intra observer variability in target definition. Different approaches to incorporate uncertainties into IMRT optimization have been proposed. In this note, we point out...

journal_title：Physics in medicine and biology

authors： Unkelbach J,Oelfke U

更新日期：2006-12-07 00:00:00

abstract：:In this study, two computational phantoms of the newborn patient were used to assess individual organ doses and effective doses delivered during head, chest, abdomen, pelvis, and torso examinations using the Siemens SOMATOM Sensation 16 helical multi-slice computed tomography (MSCT) scanner. The stylized phantom used ...

journal_title：Physics in medicine and biology

authors： Staton RJ,Lee C,Lee C,Williams MD,Hintenlang DE,Arreola MM,Williams JL,Bolch WE

更新日期：2006-10-21 00:00:00

abstract：:A Monte Carlo computational model of a fluoroscopic imaging chain was used for deriving optimal technique factors for paediatric fluoroscopy. The optimal technique was defined as the one that minimizes the absorbed dose (or dose rate) in the patient with a constraint of constant image quality. Image quality was assess...

journal_title：Physics in medicine and biology

authors： Tapiovaara MJ,Sandborg M,Dance DR

更新日期：1999-02-01 00:00:00

abstract：:In CT imaging, a variety of applications exist which are strongly SNR limited. However, in some cases redundant data of the same body region provide additional quanta. Examples in dual energy CT, the spatial resolution has to be compromised to provide good SNR for material decomposition. However, the respective spectr...

journal_title：Physics in medicine and biology

authors： Bruder H,Raupach R,Sunnegardh J,Allmendinger T,Klotz E,Stierstorfer K,Flohr T

更新日期：2015-11-07 00:00:00

abstract：:This study evaluates the dosimetric performance of the polymer gel dosimeter 'Methacrylic and Ascorbic acid in Gelatin, initiated by Copper' and its suitability for quality assurance and analysis of I-131-targeted radionuclide therapy dosimetry. Four batches of gel were manufactured in-house and sets of calibration vi...

journal_title：Physics in medicine and biology

authors： Gear JI,Charles-Edwards E,Partridge M,Flux GD

更新日期：2011-11-21 00:00:00

abstract：:The imaging performance of a high-resolution preclinical micro-positron emission tomography (micro-PET) system employing liquid xenon (LXe) as the gamma-ray detection medium was simulated. The arrangement comprises a ring of detectors consisting of trapezoidal LXe time projection ionization chambers and two arrays of ...

journal_title：Physics in medicine and biology

authors： Miceli A,Glister J,Andreyev A,Bryman D,Kurchaninov L,Lu P,Muennich A,Retiere F,Sossi V

更新日期：2012-03-21 00:00:00

abstract：:This is a proof of principle study on an algorithm for optimizing external beam radiotherapy in terms of both photon beamlet energy and fluence. This simultaneous beamlet energy and fluence optimization is denoted modulated photon radiotherapy (XMRT). XMRT is compared with single-energy intensity modulated radiotherap...

journal_title：Physics in medicine and biology

authors： McGeachy P,Villarreal-Barajas JE,Zinchenko Y,Khan R

更新日期：2016-02-21 00:00:00

abstract：:Recently, deep learning technology has achieved various successes in medical image analysis studies including computer-aided diagnosis (CADx). However, current CADx approaches based on deep learning have a limitation in interpreting diagnostic decisions. The limited interpretability is a major challenge for practical ...

journal_title：Physics in medicine and biology

authors： Kim ST,Lee JH,Lee H,Ro YM

更新日期：2018-12-04 00:00:00

abstract：:Gel dosimetry based on magnetic resonance imaging (MRI) has previously been shown to provide verification of calculated dose distributions in soft tissue equivalent homogeneous phantoms. This study demonstrates how measurements of dose distribution can also be achieved in a phantom containing porous, lung-equivalent, ...

journal_title：Physics in medicine and biology

authors： Olberg S,Skretting A,Bruland O,Olsen DR

更新日期：2000-10-01 00:00:00

abstract：:Short- and long-term side effects following the treatment of cancer with radiation are strongly related to the amount of dose deposited to the healthy tissue surrounding the tumor. The characterization of the radiation field outside the planned target volume is the first step for estimating health risks, such as devel...

journal_title：Physics in medicine and biology

authors： Tessa CL,Berger T,Kaderka R,Schardt D,Burmeister S,Labrenz J,Reitz G,Durante M

更新日期：2014-04-21 00:00:00

abstract：:The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, o...

journal_title：Physics in medicine and biology

authors： Deeley MA,Chen A,Datteri R,Noble JH,Cmelak AJ,Donnelly EF,Malcolm AW,Moretti L,Jaboin J,Niermann K,Yang ES,Yu DS,Yei F,Koyama T,Ding GX,Dawant BM

更新日期：2011-07-21 00:00:00

abstract：:Our aim is to investigate the impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging using a population of patient respiratory traces. A total of 1295 respiratory traces acquired during whole body PET/CT imaging were classified into three types according to the qualitative shape ...

journal_title：Physics in medicine and biology

authors： Liu C,Pierce LA 2nd,Alessio AM,Kinahan PE

更新日期：2009-12-21 00:00:00

abstract：:Mitral and aortic valve replacement is a procedure which is common in cardiac surgery. Some of these replacement valves are mechanical and contain moving metal parts. Should the patient in whom such a valve has been implanted be involved in magnetic resonance imaging, there is a possible dangerous interaction between ...

journal_title：Physics in medicine and biology

authors： Robertson NM,Diaz-Gomez M,Condon B

更新日期：2000-12-01 00:00:00

abstract：:Coronary computed tomography angiography (cCTA) is a commonly used imaging modality for the evaluation of coronary artery disease. cCTA is generally reconstructed in multiple cardiac phases because different coronary arteries may be better visualized in some phases than in others due to the periodic cardiac motion. We...

journal_title：Physics in medicine and biology

authors： Hadjiiski L,Zhou C,Chan HP,Chughtai A,Agarwal P,Kuriakose J,Kazerooni E,Wei J,Patel S

更新日期：2014-08-21 00:00:00

abstract：:For proton therapy, an accurate conversion of CT HU to relative stopping power (RSP) is essential. Validation of the conversion based on real tissue samples is more direct than the current practice solely based on tissue substitutes and can potentially address variations over the population. Based on a novel dose exti...

journal_title：Physics in medicine and biology

authors： Zhang R,Baer E,Jee KW,Sharp GC,Flanz J,Lu HM

更新日期：2017-06-23 00:00:00

abstract：:The purpose of this study is to calculate Pareto surfaces in multi-criteria radiation treatment planning and to analyse the dependency of the Pareto surfaces on the objective functions used for the volumes of interest. We develop a linear approach that allows us to calculate truly Pareto optimal treatment plans, and w...

journal_title：Physics in medicine and biology

authors： Craft D,Halabi T,Bortfeld T

更新日期：2005-12-21 00:00:00

abstract：:Dosimetry of proton beams is generally evaluated in liquid water, or alternatively in solid phantoms via water equivalent ratios (WER). WER is defined as the ratio of proton range in liquid water to that in a phantom of certain material. Presently, WER is not available in the literature neither for a wide range of ene...

journal_title：Physics in medicine and biology

authors： Safigholi H,Song WY

更新日期：2018-07-27 00:00:00

abstract：:Average cross-sections for inactivation of dry ribonuclease by H, He and N projectiles with energies between 100 eV and 10 keV are presented. The trend of the damage cross-sections with particle energy is consistent with the trend of the molecular quasi-elastic scattering and ionization cross-sections. A tentative rad...

journal_title：Physics in medicine and biology

authors： Watt DE,Sutcliffe JF

更新日期：1975-11-01 00:00:00

abstract：:To evaluate a commercial synthetic CT (syn-CT) software for use in prostate radiotherapy. Twenty-five prostate patients underwent CT and MR simulation scans in treatment position on a 3T MR scanner. A commercially available MR protocol was used that included a T2w turbo spin-echo sequence for soft-tissue contrast and ...

journal_title：Physics in medicine and biology

authors： Tyagi N,Fontenla S,Zhang J,Cloutier M,Kadbi M,Mechalakos J,Zelefsky M,Deasy J,Hunt M

更新日期：2017-04-21 00:00:00

abstract：:Dual-energy x-ray absorptiometry (DXA) is widely applied for estimating body fat. The percentage of body mass as fat (%fat) is predicted from a DXA-estimated R(ST) value defined as the ratio of soft tissue attenuation at two photon energies (e.g., 40 keV and 70 keV). Theoretically, the R(ST) concept depends on the mas...

journal_title：Physics in medicine and biology

authors： Wang Z,Heymsfield SB,Chen Z,Zhu S,Pierson RN

更新日期：2010-05-07 00:00:00

abstract：:Echocardiography (echo) is a widely available method to obtain images of the heart; however, echo can suffer due to the presence of artefacts, high noise and a restricted field of view. One method to overcome these limitations is to use multiple images, using the 'best' parts from each image to produce a higher qualit...

journal_title：Physics in medicine and biology

authors： Yao C,Simpson JM,Schaeffter T,Penney GP

更新日期：2011-09-21 00:00:00

abstract：:The feasibility of detecting gamma rays with energies below 1.5 MeV by means of a large-volume liquid-filled Cerenkov counter has been examined, together with the characteristics and limitations of an experimental counter. Various liquids (water, glycerol, sodium iodide solution; and glycerol plus a wavelength shifter...

journal_title：Physics in medicine and biology

authors： Hesp R

更新日期：1978-05-01 00:00:00

abstract：:The quantification of tumor motion in sites affected by respiratory motion is of primary importance to improve treatment accuracy. To account for motion, different studies analyzed the translational component only, without focusing on the rotational component, which was quantified in a few studies on the prostate with...

journal_title：Physics in medicine and biology

authors： Paganelli C,Lee D,Greer PB,Baroni G,Riboldi M,Keall P

更新日期：2015-09-21 00:00:00

abstract：:Rotational coronary angiography provides a multitude of x-ray projections of the contrast agent enhanced coronary arteries along a given trajectory with parallel ECG recording. These data can be used to derive motion information of the coronary arteries including vessel displacement and pulsation. In this paper, a ful...

journal_title：Physics in medicine and biology

authors： Jandt U,Schäfer D,Grass M,Rasche V

更新日期：2009-01-07 00:00:00

abstract：:Proton therapy with active scanning beam delivery has significant advantages compared to conventional radiotherapy. However, so far only static targets have been treated in this way, since moving targets potentially lead to interplay effects. For 4D treatment planning, information on the target motion is needed to cal...

journal_title：Physics in medicine and biology

authors： Zhang Y,Boye D,Tanner C,Lomax AJ,Knopf A

更新日期：2012-04-07 00:00:00