Dosimetric effects of contrast media for catheter-based intravascular brachytherapy.

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：:Machine outputs, peak scatter factors, and central axis percentage depth dose distributions were measured for various phantom sizes in large radiation fields produced at extended distances by cobalt, 6-MV, and 10-MV photon beams. The results can be applied to practical total body irradiation procedures which usually i...

journal_title：Medical physics

authors： Podgorsak EB,Pla C,Evans MD,Pla M

更新日期：1985-09-01 00:00:00

abstract：:Current methods for imaging joint motion are limited to either two-dimensional (2D) video fluoroscopy, or to animated motions from a series of static three-dimensional (3D) images. 3D movement patterns can be detected from biplane fluoroscopy images matched with computed tomography images. This involves several x-ray ...

journal_title：Medical physics

authors： Carelsen B,Bakker NH,Strackee SD,Boon SN,Maas M,Sabczynski J,Grimbergen CA,Streekstra GJ

更新日期：2005-09-01 00:00:00

abstract：:The computed tomography (CT) radiation dose to pediatric patients has received considerable attention recently. Moreover, it is important to be able to determine CT radiation doses for various patient sizes ranging from infants to large adults. The current AAPM protocol only measures CT radiation dose using a 16 cm ac...

journal_title：Medical physics

authors： Nickoloff EL,Dutta AK,Lu ZF

更新日期：2003-03-01 00:00:00

abstract：:An x-ray computed microtomography system for specimen and small animal imaging was built and tested. The system used seventeen 48-microm-wide detector arrays (a charge coupled device camera) and helical acquisition techniques. Images were acquired using 540 rays/view and 400 views/2pi. The modulation transfer function...

journal_title：Medical physics

authors： Corrigan NM,Chavez AE,Wisner ER,Boone JM

更新日期：1999-08-01 00:00:00

abstract：PURPOSE:Multiple commercial, open-source, and academic software tools exist for objective quantification of lung density in computed tomography (CT) images. The purpose of this study was to evaluate the intersoftware reproducibility of CT lung density measurements. METHODS:Computed tomography images from 50 participan...

journal_title：Medical physics

authors： Kirby M,Hatt C,Obuchowski N,Humphries SM,Sieren J,Lynch DA,Fain SB,QIBA Lung Density Committee.

更新日期：2020-07-01 00:00:00

abstract：PURPOSE:In Stereotactic body radiation therapy (SBRT) higher dose per fraction is delivered to patients and thus the need for an accurate dose computation is further elevated. However under such conditions of small field geometries, the electronic equilibrium can be lost, making it challenging for the dose-calculation ...

journal_title：Medical physics

authors： Shosha M,Deiab N,Eldib A,Tohamy K

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Quantitative cone-beam CT (CBCT) imaging is on increasing demand for high-performance image guided radiation therapy (IGRT). However, the current CBCT has poor image qualities mainly due to scatter contamination. Its current clinical application is therefore limited to patient setup based on only bony structure...

journal_title：Medical physics

authors： Niu T,Al-Basheer A,Zhu L

更新日期：2012-04-01 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：:The effective energy of the x-ray beam from linear accelerators changes as a function of the position in the beam due to nonuniform filtration by the flattening filter. In this work, the transmittance through a water column was measured in good geometry and the beam quality characterized in units of HVL in water. Meas...

journal_title：Medical physics

authors： Hanson WF,Berkley LW,Peterson M

更新日期：1980-03-01 00:00:00

abstract：:Effective radioimmunotherapy may depend on a priori knowledge of the radiation absorbed dose distribution obtained by trace imaging activities administered to a patient before treatment. A new, fast, and effective treatment planning approach is developed to deal with a heterogeneous activity distribution. Calculation ...

journal_title：Medical physics

authors： Erdi AK,Yorke ED,Loew MH,Erdi YE,Sarfaraz M,Wessels BW

更新日期：1998-11-01 00:00:00

abstract：PURPOSE:Colitis refers to inflammation of the inner lining of the colon that is frequently associated with infection and allergic reactions. In this paper, we propose deep convolutional neural networks methods for lesion-level colitis detection and a support vector machine (SVM) classifier for patient-level colitis dia...

journal_title：Medical physics

authors： Liu J,Wang D,Lu L,Wei Z,Kim L,Turkbey EB,Sahiner B,Petrick NA,Summers RM

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:The objectives of this study were (a) to devise a technique for measuring quantum noise in clinical body computed tomography (CT) images and (b) to develop a model for predicting that noise with high accuracy. METHODS:The study included 83 clinical image sets at two dose levels (clinical and 50% reduced dose l...

journal_title：Medical physics

authors： Tian X,Samei E

更新日期：2016-01-01 00:00:00

abstract：:A realistic photon beam model based on Monte Carlo simulation of clinical linear accelerators was implemented in a convolution/superposition dose calculation algorithm. A primary and an extra-focal sources were used in this beam model to represent the direct photons from the target and the scattered photons from other...

journal_title：Medical physics

authors： Liu HH,Mackie TR,McCullough EC

更新日期：1997-12-01 00:00:00

abstract：:MR acoustic radiation force (ARF) imaging was developed for measuring tiSsue elastic properties using focused ultrasound to deliver a localized tissue motion. In this study, an imaging ultrasound transducer was mounted on the focused ultrasound transducer and ultrasound motion tracking was performed simultaneously to ...

journal_title：Medical physics

authors： Huang Y,Curiel L,Kukic A,Plewes DB,Chopra R,Hynynen K

更新日期：2009-06-01 00:00:00

abstract：:Different methods exist to determine the air kerma calibration factor of an ionization chamber for the spectrum of a 192Ir high-dose-rate (HDR) or pulsed-dose-rate (PDR) source. An analysis of two methods to obtain such a calibration factor was performed: (i) the method recommended by [Goetsch et al., Med. Phys. 18, 4...

journal_title：Medical physics

authors： van Dijk E,Kolkman-Deurloo IK,Damen PM

更新日期：2004-10-01 00:00:00

abstract：PURPOSE:Stereotactic ablative body radiotherapy (SABR) for lung patients can be performed with volumetric-modulated arc therapy (VMAT) plans using off-axis target geometry to allow treatment in their CBCT verified position. For patient-specific quality assurance measurements using the PTW Octavius 4D phantom (PTW, Frei...

journal_title：Medical physics

authors： Jeevanandam P,Agnew CE,Irvine DM,McGarry CK

更新日期：2018-04-01 00:00:00

abstract：:Beam hardening is a well-known phenomenon for therapeutic accelerator beams passing through matter in narrow beam geometry. This study assesses quantitatively the magnitude of beam hardening of therapeutic beams in water. A formal concept of beam hardening is proposed which is based on the decrease of the mean attenua...

journal_title：Medical physics

authors： Kleinschmidt C

更新日期：1999-09-01 00:00:00

abstract：:New in vivo dosimetry methods would be useful for clinical HDR brachytherapy. An implantable MOSFET Dose Verification System designed by Sicel Technologies, Inc. was examined for use with 192Ir HDR applications. This investigation demonstrated that varying the dose rate from 22 to 84 cGy/min did not change detector re...

journal_title：Medical physics

authors： Fagerstrom JM,Micka JA,DeWerd LA

更新日期：2008-12-01 00:00:00

abstract：:As different types of radionuclides (e.g., 131Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically ...

journal_title：Medical physics

authors： Yue NJ

更新日期：2008-06-01 00:00:00

abstract：PURPOSE:A radiophotoluminescent glass rod dosimeter (RGD) has recently become commercially available. It is being increasingly used for dosimetry in radiotherapy to measure the absorbed dose including scattered low-energy photons on the body surface of a patient and for postal dosimetry audit. In this article, the dosi...

journal_title：Medical physics

authors： Kadoya N,Shimomura K,Kitou S,Shiota Y,Fujita Y,Dobashi S,Takeda K,Jingu K,Matsushita H,Namito Y,Ban S,Koyama S,Tabushi K

更新日期：2012-10-01 00:00:00

abstract：PURPOSE:The variable resolution x-ray (VRX) CT scanner provides substantial improvement in the spatial resolution by matching the scanner's field of view (FOV) to the size of the object being imaged. Intercell x-ray cross-talk is one of the most important factors limiting the spatial resolution of the VRX detector. In ...

journal_title：Medical physics

authors： Arabi H,Asl AR,Ay MR,Zaidi H

更新日期：2011-03-01 00:00:00

abstract：PURPOSE:The aiming is getting accurate liver contour structures automatically for following adaptive radiation therapy in daily CBCT images which is very low-contrast comparing the planning CT. METHODS:Probabilistic atlas is constructed by 50 intravenous contrast planning CT images by iterative affine registration pro...

journal_title：Medical physics

authors： Li D,Li H,Yin Y,Chen J

更新日期：2012-06-01 00:00:00

abstract：:Hyperthermia, as an adjuvant with radiation and chemotherapy, has shown promise in the treatment of cancer. The relevant biological effects of a hyperthermia treatment are both time and temperature-dependent, creating a need for accurate thermometry. We present a novel noninvasive thermometry modality that combines a ...

journal_title：Medical physics

authors： Dreher MR,Elas M,Ichikawa K,Barth ED,Chilkoti A,Rosen GM,Halpern HJ,Dewhirst M

更新日期：2004-10-01 00:00:00

abstract：PURPOSE:The recent development of multifocal stereotactic radiosurgery (SRS) using a single isocenter volumetric modulated arc theory (VMAT) technique warrants a re-examination of the quality assurance (QA) tolerances for routine mechanical QA recommended by the American Association of Physicists in Medicine Task Group...

journal_title：Medical physics

authors： Faught AM,Trager M,Yin FF,Kirkpatrick J,Adamson J

更新日期：2016-10-01 00:00:00

abstract：PURPOSE:Radiation therapy is often delivered by multiple sequential treatment plans. For an accurate radiobiological evaluation of the overall treatment, fractionation corrections to each dose distribution must be applied before summing the three-dimensional dose matrix of each plan since the simpler approach of perfor...

journal_title：Medical physics

authors： Mavroidis P,Ferreira BC,Papanikolaou N,Lopes Mdo C

更新日期：2013-03-01 00:00:00

abstract：PURPOSE:To compare the estimate of normalized glandular dose in mammography and breast CT imaging obtained using the actual glandular tissue distribution in the breast to that obtained using the homogeneous tissue mixture approximation. METHODS:Twenty volumetric images of patient breasts were acquired with a dedicated...

journal_title：Medical physics

authors： Sechopoulos I,Bliznakova K,Qin X,Fei B,Feng SS

更新日期：2012-08-01 00:00:00

abstract：:It has recently been shown that longitudinal aliasing can be a significant and detrimental presence in reconstructed single-slice helical computed tomography (CT) volumes. This aliasing arises because the directly measured data in helical CT are generally undersampled by a factor of at least 2 in the longitudinal dire...

journal_title：Medical physics

authors： La Rivière PJ,Pan X

更新日期：2001-03-01 00:00:00

abstract：PURPOSE:Repeated brain MRI scans are performed in many clinical scenarios, such as follow up of patients with tumors and therapy response assessment. In this paper, the authors show an approach to utilize former scans of the patient for the acceleration of repeated MRI scans. METHODS:The proposed approach utilizes the...

journal_title：Medical physics

authors： Weizman L,Eldar YC,Ben Bashat D

更新日期：2015-09-01 00:00:00

abstract：:The concept of the radiological depth is central to all algorithms which calculate radiation dose in a heterogeneous medium. For a discrete heterogeneous medium, consisting of regions of inhomogeneity, the radiological depth is usually presented as the sum over segments of the product of the segment length and the inh...

journal_title：Medical physics

authors： Siddon RL

更新日期：1985-01-01 00:00:00