Image reconstruction and scan configurations enabled by optimization-based algorithms in multispectral CT.

abstract：:Two complementary approaches to the noise suppression problem in on-line portal imaging have been analysed. Temporal filtering by image summation can substantially reduce the amount of noise in an image. In many cases, however, movements of the patient or the radiation source limit the time period over which the avera...

journal_title：Physics in medicine and biology

authors： Leszczynski KW,Shalev S,Cosby NS

更新日期：1990-03-01 00:00:00

abstract：:A dynamic-contrast-enhanced magnetic resonance imaging (DCE-MRI) dataset consists of many imaging frames, often acquired both before and after contrast injection. Due to the length of time spent acquiring images, patient motion is likely and image re-alignment or registration is required before further analysis such a...

journal_title：Physics in medicine and biology

authors： Melbourne A,Hipwell J,Modat M,Mertzanidou T,Huisman H,Ourselin S,Hawkes DJ

更新日期：2011-12-21 00:00:00

abstract：:In this study, we evaluate the feasibility of designing a beveled fiber-optic probe coupled with a ball lens for improving depth-resolved fluorescence measurements of epithelial tissue using Monte Carlo (MC) simulations. The results show that by using the probe configuration with a beveled tip collection fiber and a f...

journal_title：Physics in medicine and biology

authors： Jaillon F,Zheng W,Huang Z

更新日期：2008-02-21 00:00:00

abstract：:The treatment of large tumors such as sarcomas with intra-operative radiotherapy using a Mobetron is often complicated because of the limited field size of the primary collimator and the available applicators (max Ø100 mm). To circumvent this limitation a prototype rectangular applicator of 80 x 150 mm(2) was designed...

journal_title：Physics in medicine and biology

authors： Janssen RW,Faddegon BA,Dries WJ

更新日期：2008-04-21 00:00:00

abstract：:Ultrasound-based elastography including strain elastography, acoustic radiation force impulse (ARFI) imaging, point shear wave elastography and supersonic shear imaging (SSI) have been used to differentiate breast tumors among other clinical applications. The objective of this study is to extend a previously published...

journal_title：Physics in medicine and biology

authors： Wang Y,Peng B,Jiang J

更新日期：2017-03-07 00:00:00

abstract：:Recently, there has been an increased interest in imaging different pulmonary disorders using PET techniques. Previous work has shown, for static PET/CT, that air content in the lung influences reconstructed image values and that it is vital to correct for this 'tissue fraction effect' (TFE). In this paper, we extend ...

journal_title：Physics in medicine and biology

authors： Holman BF,Cuplov V,Millner L,Hutton BF,Maher TM,Groves AM,Thielemans K

更新日期：2015-09-21 00:00:00

abstract：:A simple and fast, but sensitive TLD method for the measurement of energy and homogeneity of therapeutically used electron beams has been developed and tested. This method is based on the fact that when small thicknesses of high-Z absorbers such as lead are interposed in the high-energy electron beams, the transmitted...

journal_title：Physics in medicine and biology

authors： Pradhan AS,Quast U,Sharma PK

更新日期：1994-09-01 00:00:00

abstract：:The standard mammogram form (SMF) representation of an x-ray mammogram is a standardized, quantitative representation of the breast from which the volume of non-fat tissue and breast density can be easily estimated, both of which are of significant interest in determining breast cancer risk. Previous theoretical analy...

journal_title：Physics in medicine and biology

authors： Highnam R,Pan X,Warren R,Jeffreys M,Davey Smith G,Brady M

更新日期：2006-06-07 00:00:00

abstract：:Although interventional x-ray angiography (XA) procedures involve relatively high radiation doses that can lead to deterministic tissue reactions in addition to stochastic effects, convenient and accurate estimation of absorbed organ doses has traditionally been out of reach. This has mainly been due to the absence of...

journal_title：Physics in medicine and biology

authors： Omar A,Bujila R,Fransson A,Andreo P,Poludniowski G

更新日期：2016-04-21 00:00:00

abstract：:Reducing radiation dose in dual energy computed tomography (DECT) is highly desirable but it may lead to excessive noise in the filtered backprojection (FBP) reconstructed DECT images, which can inevitably increase the diagnostic uncertainty. To obtain clinically acceptable DECT images from low-mAs acquisitions, in th...

journal_title：Physics in medicine and biology

authors： Zhang H,Zeng D,Lin J,Zhang H,Bian Z,Huang J,Gao Y,Zhang S,Zhang H,Feng Q,Liang Z,Chen W,Ma J

更新日期：2017-07-07 00:00:00

abstract：:Iterative tomographic reconstruction has been established as a viable alternative for data analysis in phase-sensitive x-ray imaging based on the edge-illumination principle. However, previously published approaches did not account for drifts of optical elements during a scan, which can lead to artefacts. Up to now, t...

journal_title：Physics in medicine and biology

authors： Modregger P,Meganck J,Hagen CK,Massimi L,Olivo A,Endrizzi M

更新日期：2019-10-10 00:00:00

abstract：:For quantitative measurements of small animals such as mice or rats, a compact and high sensitivity continuous blood sampling detector is required because their blood sampling volume is limited. For this purpose we have developed and tested a new positron detector. The positron detector uses a pair of dual-layer thin ...

journal_title：Physics in medicine and biology

authors： Yamamoto S,Imaizumi M,Shimosegawa E,Kanai Y,Sakamoto Y,Minato K,Shimizu K,Senda M,Hatazawa J

更新日期：2010-07-07 00:00:00

abstract：:All particle beam scanning systems are subject to dose delivery errors due to errors in position, energy and intensity of the delivered beam. In addition, finite scan speeds, beam spill non-uniformities, and delays in detector, detector electronics and magnet responses will all contribute errors in delivery. In this p...

journal_title：Physics in medicine and biology

authors： Coutrakon G,Wang N,Miller DW,Yang Y

更新日期：2010-12-07 00:00:00

abstract：:The aim of this study was to systematically investigate the influence of the inter- and intra-observer segmentation variation of tumors and organs at risk on the simulated temperature coverage of the target. CT scans of six patients with tumors in the pelvic region acquired for radiotherapy treatment planning were use...

journal_title：Physics in medicine and biology

authors： Aklan B,Hartmann J,Zink D,Siavooshhaghighi H,Merten R,Putz F,Ott O,Fietkau R,Bert C

更新日期：2017-05-08 00:00:00

abstract：:The effect of the physical state (phase) of the absorbing medium and the energy straggling of the alpha particles on the calculation of the radiation dose due to the daughter products of radon deposited in the lung have been studied in detail. The stopping power data for alpha particles in water and water vapour have ...

journal_title：Physics in medicine and biology

authors： Haque AK,Al-affan IA

更新日期：1987-08-01 00:00:00

abstract：:Stereotactic Gamma Knife radiosurgery utilizes ionizing beams from (60)Co sources and relies on a combination of collimator sizes, weighting, etc to generate a high-dose region that is conformal with a designated target volume. Dose computation is typically performed by computer, but in this paper, single collimator d...

journal_title：Physics in medicine and biology

authors： Fenner J,Gwilliam M,Mehrem R,Bird A,Walton L

更新日期：2008-04-21 00:00:00

abstract：:The purpose of this work is the clinical commissioning of a recently developed in vivo range verification system (IRVS) for treatment of prostate cancer by anterior and anterior oblique proton beams. The IRVS is designed to perform a complete workflow for pre-treatment range verification and adjustment. It contains sp...

journal_title：Physics in medicine and biology

authors： Hoesl M,Deepak S,Moteabbed M,Jassens G,Orban J,Park YK,Parodi K,Bentefour EH,Lu HM

更新日期：2016-04-21 00:00:00

abstract：:Coronary flow rate remains complex to assess in clinical practice using non-invasive, non-ionizing imaging tools. In this study, we introduce 3D ultrafast Doppler coronary angiography (3D UDCA), an ultrasound-based method to assess coronary blood flows in three-dimensions at high volume-rate and in one single heartbea...

journal_title：Physics in medicine and biology

authors： Correia M,Maresca D,Goudot G,Villemain O,Bizé A,Sambin L,Tanter M,Ghaleh B,Pernot M

更新日期：2020-06-05 00:00:00

abstract：:Diffraction-enhanced imaging (DEI) is a new x-ray imaging modality that has been shown to enhance contrast between normal and cancerous breast tissues. In this study, diffraction-enhanced imaging in computed tomography (DEI-CT) mode was used to quantitatively characterize the refraction contrasts of the organized stru...

journal_title：Physics in medicine and biology

authors： Kao T,Connor D,Dilmanian FA,Faulconer L,Liu T,Parham C,Pisano ED,Zhong Z

更新日期：2009-05-21 00:00:00

abstract：:It is not feasible to define very small or complex organs and tissues in the current voxel-type adult reference computational phantoms of the International Commission on Radiological Protection (ICRP), which limit dose coefficients for weakly penetrating radiations. To address the problem, the ICRP is converting the v...

journal_title：Physics in medicine and biology

authors： Kim HS,Yeom YS,Nguyen TT,Choi C,Han MC,Lee JK,Kim CH,Zankl M,Petoussi-Henss N,Bolch WE,Lee C,Qiu R,Eckerman K,Chung BS

更新日期：2017-03-21 00:00:00

abstract：:A method to measure the detector-to-object distance from the images obtained with stationary high-spatial-resolution gamma-ray cameras for in vivo studies has been developed. It exploits the shift of the imaged object in the image plane, obtained at a certain tilt of the parallel-hole collimator. A linear dependence o...

journal_title：Physics in medicine and biology

authors： Uzunov N,Bello M,Boccaccio P,Moschini G,Bollini D,de Notaristefani F

更新日期：2006-05-07 00:00:00

abstract：:The presence of motion artifacts is a typical problem in thoracic imaging. However, synchronizing the respiratory cycle with computed tomography (CT) image acquisition can reduce these artifacts. We currently employ a method of in vivo respiratory-gated micro-CT imaging for small laboratory animals (mice). This proced...

journal_title：Physics in medicine and biology

authors： Walters EB,Panda K,Bankson JA,Brown E,Cody DD

更新日期：2004-09-07 00:00:00

abstract：:The first trimester fetal ultrasound scan is important to confirm fetal viability, to estimate the gestational age of the fetus, and to detect fetal anomalies early in pregnancy. First trimester ultrasound images have a different appearance than for the second trimester scan, reflecting the different stage of fetal de...

journal_title：Physics in medicine and biology

authors： Ryou H,Yaqub M,Cavallaro A,Papageorghiou AT,Alison Noble J

更新日期：2019-09-17 00:00:00

abstract：:Range verification is one of the most relevant tasks in ion beam therapy. In the case of carbon ion therapy, positron emission tomography (PET) is the most widely used method for this purpose, which images the [Formula: see text]-activation following nuclear interactions of the ions with the tissue nuclei. Since the p...

journal_title：Physics in medicine and biology

authors： Hofmann T,Fochi A,Parodi K,Pinto M

更新日期：2019-05-21 00:00:00

abstract：:A three-dimensional (3D) point-kernel multiple scatter model for point spread function (PSF) determination in parallel-beam single-photon emission computed tomography (SPECT), based on a dose gamma-ray buildup factor, is proposed. This model embraces nonuniform attenuation in a voxelized object of imaging (patient bod...

journal_title：Physics in medicine and biology

authors： Marinkovic P,Ilic R,Spaic R

更新日期：2007-10-07 00:00:00

abstract：:Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units ...

journal_title：Physics in medicine and biology

authors： Salter BJ,Sarkar V,Wang B,Shukla H,Szegedi M,Rassiah-Szegedi P

更新日期：2011-04-07 00:00:00

abstract：:The medical imaging and therapeutic technologies that are based on the use of radiation are reviewed briefly, with special emphasis on the recent developments of synchrotron radiation (SR) methods. New results have been achieved in all of these areas since the last comprehensive reviews were written in this field. Thi...

journal_title：Physics in medicine and biology

authors： Suortti P,Thomlinson W

更新日期：2003-07-07 00:00:00

abstract：:This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical obs...

journal_title：Physics in medicine and biology

authors： Lee TS,Frey EC,Tsui BM

更新日期：2015-04-07 00:00:00

abstract：:Dynamic modulation can be affected by inaccuracies when the required acceleration is larger than the highest allowed by the mechanical characteristics of the whole apparatus. In this study, inertia effects have been investigated with regard to the single absorber 1D modulation, analysing primarily how the acceleration...

journal_title：Physics in medicine and biology

authors： Corletto D,Broggi S,Fiorino C,Mangili P,Calandrino R,Lev A,Gennari D,Rudello F

更新日期：1999-11-01 00:00:00

abstract：:Enabling automated pipelines, image analysis and big data methodology in cancer clinics requires thorough understanding of the data. Automated quality assurance steps could improve the efficiency and robustness of these methods by verifying possible data biases. In particular, in head and neck (H&N) computed-tomograph...

journal_title：Physics in medicine and biology

authors： Welch ML,McIntosh C,Purdie TG,Wee L,Traverso A,Dekker A,Haibe-Kains B,Jaffray DA

更新日期：2020-01-10 00:00:00