A filtering method for signal equalization in region-of-interest fluoroscopy.

abstract：PURPOSE:Radiation Therapy (RT) induced pulmonary function change may depend on the location, underlying function of that lung prior to radiations, radiation dose/fractionation and other factors. We propose to evaluate the radiation induced pulmonary function change using static breath-hold MRI scans with vascular infor...

journal_title：Medical physics

authors： Ding K,Cao K,Du K,Chen Q,Ennis D,Christensen G,Reinhardt J,Libby B,Benedict S,Sheng K

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Real-time sub-millimeter head motion compensation during frameless SRS delivery has the potential to achieve the accuracy of frame-based SRS while being significantly less invasive. Previously, we demonstrated real-time 6D head motion monitoring using an optical camera, however, at the time we were limited to o...

journal_title：Medical physics

authors： Belcher AH,Wiersma RD

更新日期：2012-06-01 00:00:00

abstract：:Traditionally, short scan helical FDK algorithms have been implemented based on horizontal transaxial slices. However, not every point on the horizontal transaxial slice satisfies Tuy's condition for the corresponding (pi+fan angle) segment of helix, which means that some points on the horizontal slices are incomplete...

journal_title：Medical physics

authors： Hu J,Tam K,Qi J

更新日期：2005-06-01 00:00:00

abstract：:Nuclear Magnetic Resonance (NMR) permits the noninvasive measurement of blood flow signals unimpaired by clothes, bandages, casts, etc. The cylindrical crossed-coil NMR blood flowmeter was used to measure blood flow through a cross-section of the human forearm. Two calibration procedures are described: one for pulsati...

journal_title：Medical physics

authors： Salles-Cunha SX,Halbach RE,Battocletti JH,Sances A Jr

更新日期：1981-07-01 00:00:00

abstract：:Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Sev...

journal_title：Medical physics

authors： Tutar IB,Managuli R,Shamdasani V,Cho PS,Pathak SD,Kim Y

更新日期：2003-12-01 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:To study if malfunction of a receiver can be detected robustly using the simple ACR SNR measurement approach on a 32-channel head coil. METHODS:Standard ACR T1W images (11slice) were acquired with a commercial 32 channel head coil on a 3T Philips Achieva MR scanner following the ACR recommended setup. Raw data...

journal_title：Medical physics

authors： Peng Q

更新日期：2012-06-01 00:00:00

abstract：:When an (exposure) calibrated ionization chamber is used for the determination of absorbed dose from a photon beam, the reading of the instrument must be multiplied by a number of factors, one of which is an attenuation correction for phantom material displaced by the chamber. the magnitude of this correction must dep...

journal_title：Medical physics

authors： Cunningham JR,Sontag MR

更新日期：1980-11-01 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:Primary goal of this study is to select optimal registration schemes in the framework of interstitial lung disease (ILD) follow-up analysis in CT. METHODS:A set of 128 multiresolution schemes composed of multiresolution nonrigid and combinations of rigid and nonrigid registration schemes are evaluated, utilizi...

journal_title：Medical physics

authors： Vlachopoulos G,Korfiatis P,Skiadopoulos S,Kazantzi A,Kalogeropoulou C,Pratikakis I,Costaridou L

更新日期：2015-08-01 00:00:00

abstract：PURPOSE:This work concerns computed tomography (CT)-based cardiac functional analysis (CFA) with a reduced radiation dose. As CT-CFA requires images over the entire heartbeat, the scans are often performed at 10-20% of the tube current settings that are typically used for coronary CT angiography. A large image noise th...

journal_title：Medical physics

authors： Fung GSK,Ciuffo L,Ashikaga H,Taguchi K

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:The objectives are: (i) assess the development of the impedance of some arteries during the first decades of life; (ii) determine the influence of pulse rate in arterial impedance; (iii) compare the structure of some arterial segments with optimized structures with respect to blood flow; and (iv) explain the el...

journal_title：Medical physics

authors： Silva C,Reis AH

更新日期：2014-06-01 00:00:00

abstract：PURPOSE:Prostate biopsy, performed using two-dimensional (2D) transrectal ultrasound (TRUS) guidance, is the clinical standard for a definitive diagnosis of prostate cancer. Histological analysis of the biopsies can reveal cancerous, noncancerous, or suspicious, possibly precancerous, tissue. During subsequent biopsy s...

journal_title：Medical physics

authors： Karnik VV,Fenster A,Bax J,Cool DW,Gardi L,Gyacskov I,Romagnoli C,Ward AD

更新日期：2010-02-01 00:00:00

abstract：PURPOSE:To develop a hypothesis-generating framework for automatic extraction of dose-outcome relationships from an in-house, analytic oncology database. METHODS:Dose-volume histograms (DVH) and clinical outcomes have been routinely stored to the authors' database for 684 head and neck cancer patients treated from 200...

journal_title：Medical physics

authors： Robertson SP,Quon H,Kiess AP,Moore JA,Yang W,Cheng Z,Afonso S,Allen M,Richardson M,Choflet A,Sharabi A,McNutt TR

更新日期：2015-07-01 00:00:00

abstract：PURPOSE:Radiotherapy, especially with charged particles, is sensitive to executional and preparational uncertainties that propagate to uncertainty in dose and plan quality indicators, for example, dose-volume histograms (DVHs). Current approaches to quantify and mitigate such uncertainties rely on explicitly computed e...

journal_title：Medical physics

authors： Wahl N,Hennig P,Wieser HP,Bangert M

更新日期：2020-10-01 00:00:00

abstract：:The EGS4 Monte Carlo code has been used to investigate the response of a PTW/diamond detector irradiated in both clinical and monoenergetic megavoltage electron beams ranging in energy from 5 to 20 MeV. The sensitive volume of the PTW/diamond detector simulated has a thickness of 0.4 mm and a diameter of 4.4 mm. Irrad...

journal_title：Medical physics

authors： Mobit PN,Sandison GA

更新日期：1999-05-01 00:00:00

abstract：:Inverse treatment planning of intensity-modulated radiation therapy (IMRT) is complicated by several sources of error, which can cause deviations of optimized plans from the true optimal solution. These errors include the systematic and convergence error, the local minima error, and the optimizer convergence error. We...

journal_title：Medical physics

authors： Hartmann M,Bogner L

更新日期：2008-05-01 00:00:00

abstract：:Determination of the relaxation times T1 and T2 which are important for tissue characterization generally requires the use of different pulse sequences in magnetic resonance imaging. In this study, a new pulse sequence which facilitates simultaneous determination of the T1 and T2 times is presented. Determination take...

journal_title：Medical physics

authors： Graumann R,Fischer H,Oppelt A

更新日期：1986-09-01 00:00:00

abstract：:Energy imparted is a measure of the total ionizing energy deposited in the patient during a radiologic examination and may be used to quantify the patient dose in diagnostic radiology. Values of the energy imparted per unit exposure-area product, omega (z), absorbed by a semi-infinite water phantom with a thickness z,...

journal_title：Medical physics

authors： Gkanatsios NA,Huda W

更新日期：1997-04-01 00:00:00

abstract：PURPOSE:In radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, the information on electron density must be derived from the MRI scan by creating a so-called pseudo computed tomography (pCT). This is a nontrivial task, since the voxel-intensities in an MRI scan are not uniquely related to e...

journal_title：Medical physics

authors： Andreasen D,Van Leemput K,Hansen RH,Andersen JA,Edmund JM

更新日期：2015-04-01 00:00:00

abstract：PURPOSE:Although x-ray projection mammography has been very effective in early detection of breast cancer, its utility is reduced in the detection of small lesions that are occult or in dense breasts. One drawback is that the inherent superposition of parenchymal structures makes visualization of small lesions difficul...

journal_title：Medical physics

authors： Le Huy Q,Ducote JL,Molloi S

更新日期：2010-03-01 00:00:00

abstract：PURPOSE:A dosimetry evaluation model for treatment planning of esophageal radiation therapy is developed using a deep learning model. The model predicts dose volume histogram (DVH) from distance to target histogram (DTH) based on stacked de-noise auto-encoder (SDAE) and one-dimensional convolutional network (1D-CN). M...

journal_title：Medical physics

authors： Jiang D,Yan H,Chang N,Li T,Mao R,Du C,Guo B,Liu J

更新日期：2020-10-01 00:00:00

abstract：PURPOSE:Removal of the linear accelerator (linac) flattening filter enables a high rate of dose deposition with reduced treatment time. When used for megavoltage imaging, an unflat beam has reduced primary beam scatter resulting in sharper images. In fluoroscopic imaging mode, the unflat beam has higher photon count pe...

journal_title：Medical physics

authors： Christensen JD,Kirichenko A,Gayou O

更新日期：2013-08-01 00:00:00

abstract：PURPOSE:The advent of three-dimensional breast imaging systems such as digital breast tomosynthesis (DBT) has great promise for improving the detection and diagnosis of breast cancer. With these new technologies comes an essential need for testing methods to assess the resultant image quality. Although randomized clini...

journal_title：Medical physics

authors： Ikejimba LC,Salad J,Graff CG,Ghammraoui B,Cheng WC,Lo JY,Glick SJ

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:Planning for the delivery of intensity-modulated radiation therapy (IMRT) to a moving target, referred to as four-dimensional (4D) IMRT planning, is a crucial step for achieving the treatment objectives for sites that move during treatment delivery. The authors proposed a simplistic method that accounts for bot...

journal_title：Medical physics

authors： Gui M,Feng Y,Yi B,Dhople AA,Yu C

更新日期：2010-05-01 00:00:00

abstract：PURPOSE:Cone beam computed tomography (CBCT) image quality suffers from contamination from scattered photons in the projection images. Monte Carlo simulations are a powerful tool to investigate the properties of scattered photons.egs_cbct, a recent EGSnrc user code, provides the ability of performing fast scatter calcu...

journal_title：Medical physics

authors： Thing RS,Mainegra-Hing E

更新日期：2014-07-01 00:00:00

abstract：:In patients with lymphoma, identification and quantification of the tumor extent on serial CT examinations is critical for assessing tumor response to therapy. In this paper, we present a computer method to automatically match and segment lymphomas in follow-up CT images. The method requires that target lymph nodes in...

journal_title：Medical physics

authors： Yan J,Zhao B,Curran S,Zelenetz A,Schwartz LH

更新日期：2007-01-01 00:00:00

abstract：PURPOSE:A dosimetric system formed by Gafchromic EBT2 radiochromic film and Epson Expression 10000XL flatbed scanner was commissioned for dosimetry. In this paper, several open questions concerning the commissioning of radiochromic films for dosimetry were addressed: (a) is it possible to employ this dosimetric system ...

journal_title：Medical physics

authors： Mendez I,Hartman V,Hudej R,Strojnik A,Casar B

更新日期：2013-01-01 00:00:00

abstract：:It is known that motion of an object imaged by magnetic resonance imaging leads to errors and artifacts in the image. This effect is especially important when a pulse sequence with long echo time (TE) and long TR is used to provide T2-weighted images. We have modified the usual spin warp imaging pulse sequence in a wa...

journal_title：Medical physics

authors： Joseph PM,Shetty A,Bonaroti EA

更新日期：1987-07-01 00:00:00

abstract：PURPOSE:Brachytherapy with 106 Ru/106 Rh plaques offers good outcomes for small-to-medium choroidal melanomas and retinoblastomas. The dose measurement of the plaques is challenging, due to the small range of the emitted beta particles and steep dose gradients involved. The scarce publications on film dosimetry of 106 ...

journal_title：Medical physics

authors： Hermida-López M,Brualla L

更新日期：2018-04-01 00:00:00