Surface imaging for real-time patient respiratory function assessment in intensive care.

abstract：PURPOSE:Although robot-assisted coronary artery bypass grafting (RA-CABG) has gained more acceptance worldwide, its success still depends on the surgeon's experience and expertise, and the conversion rate to full sternotomy is in the order of 15%-25%. One of the reasons for conversion is poor pre-operative planning, wh...

journal_title：Medical physics

authors： Cho DS,Linte C,Chen EC,Bainbridge D,Wedlake C,Moore J,Barron J,Patel R,Peters T

更新日期：2012-03-01 00:00:00

abstract：PURPOSE:The aim of this study was to evaluate the suitability of several detectors for the determination of absorbed dose in bone. METHODS:Three types of ultrathin LiF-based thermoluminescent dosimeters (TLDs)-two LiF:Mg,Cu,P-based (MCP-Ns and TLD-2000F) and a (7)Li-enriched LiF:Mg,Ti-based (MTS-7s)-as well as EBT2 Ga...

journal_title：Medical physics

authors： Bueno M,Carrasco P,Jornet N,Muñoz-Montplet C,Duch MA

更新日期：2014-08-01 00:00:00

abstract：PURPOSE:Task Group 119 (TG-119) has been adopted for evaluating the adequacy of intensity-modulated radiation therapy (IMRT) commissioning and for establishing patient-specific IMRT quality assurance (QA) passing criteria in clinical practice. TG-119 establishes 95% confidence limits (CLs), which help clinics identify ...

journal_title：Medical physics

authors： Kearney V,Solberg T,Jensen S,Cheung J,Chuang C,Valdes G

更新日期：2018-03-01 00:00:00

abstract：:To account for clinical divergent and polychromatic photon beams, we have developed kernel tilting and kernel hardening correction methods for convolution dose calculation algorithms. The new correction methods were validated by Monte Carlo simulation. The accuracy and computation time of the our kernel tilting and ke...

journal_title：Medical physics

authors： Liu HH,Mackie TR,McCullough EC

更新日期：1997-11-01 00:00:00

abstract：PURPOSE:Cardiac motion is typically not accounted for during pretreatment imaging for central lung and mediastinal tumors. However, cardiac induced tumor motion averages 5.8 mm for esophageal tumors and 3-5 mm for some lung tumors, which can result in positioning errors. Our aim is to reduce both cardiac- and respirato...

journal_title：Medical physics

authors： Reynolds T,Shieh CC,Keall PJ,O'Brien RT

更新日期：2019-09-01 00:00:00

abstract：:Intensity modulated radiation therapy (IMRT) treatment planning typically considers beam optimization and beam delivery as separate tasks. Following optimization, a multi-leaf collimator (MLC) or other beam delivery device is used to generate fluence patterns for patient treatment delivery. Due to limitations and char...

journal_title：Medical physics

authors： Siebers JV,Lauterbach M,Keall PJ,Mohan R

更新日期：2002-06-01 00:00:00

abstract：PURPOSE:To investigate how x-ray tube projection angle affects organ and effective doses to patients undergoing a CT examination on a cone beam scanner. METHODS:The authors investigated two cone beam CT systems that use a flat panel detector to capture the x-ray pattern transmitted through patients. One system had the...

journal_title：Medical physics

authors： He W,Huda W,Magill D,Tavrides E,Yao H

更新日期：2010-05-01 00:00:00

abstract：PURPOSE:Though failure mode and effects analysis (FMEA) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge, its output has never been validated against data on errors that actually occur. The objective of this study was to perform FMEA of a stereotactic body radiation therapy (SB...

journal_title：Medical physics

authors： Yang F,Cao N,Young L,Howard J,Logan W,Arbuckle T,Sponseller P,Korssjoen T,Meyer J,Ford E

更新日期：2015-06-01 00:00:00

abstract：:Respiration can cause tumors in the thorax or abdomen to move by as much as 3 cm; this movement can adversely affect the planning and delivery of radiation treatment. Several techniques have been used to compensate for respiratory motion, but all have shortcomings. Manufacturers of computed tomography (CT) equipment h...

journal_title：Medical physics

authors： Fitzpatrick MJ,Starkschall G,Antolak JA,Fu J,Shukla H,Keall PJ,Klahr P,Mohan R

更新日期：2006-01-01 00:00:00

abstract：:A comprehensive performance testing program is an essential ingredient of high-quality single-photon emission computed tomography (SPECT). Many of the procedures previously published are complicated, time consuming, or require a special testing environment. This Task Group developed a protocol for evaluating SPECT ima...

journal_title：Medical physics

authors： Graham LS,Fahey FH,Madsen MT,van Aswegen A,Yester MV

更新日期：1995-04-01 00:00:00

abstract：:Several investigators have approximated the scatter component of digital radiographic images by applying a constant weighting factor to a convolved version of the detected image. The scatter approximation is then subtracted from the detected image. When a constant weighting factor is used, the scatter in areas of low ...

journal_title：Medical physics

authors： Naimuddin S,Hasegawa B,Mistretta CA

更新日期：1987-05-01 00:00:00

abstract：PURPOSE:Alpha-emitting radionuclides exhibit a potential advantage for cancer treatments because they release large amounts of ionizing energy over a few cell diameters (50-80 μm), causing localized, irreparable double-strand DNA breaks that lead to cell death. Radioimmunotherapy (RIT) approaches using monoclonal antib...

journal_title：Medical physics

authors： Miller BW,Frost SH,Frayo SL,Kenoyer AL,Santos E,Jones JC,Green DJ,Hamlin DK,Wilbur DS,Fisher DR,Orozco JJ,Press OW,Pagel JM,Sandmaier BM

更新日期：2015-07-01 00:00:00

abstract：PURPOSE:Transrectal ultrasound (TRUS)-guided needle biopsy is the current gold standard for prostate cancer diagnosis. However, up to 40% of prostate cancer lesions appears isoechoic on TRUS. Hence, TRUS-guided biopsy has a high false negative rate for prostate cancer diagnosis. Magnetic resonance imaging (MRI) is bett...

journal_title：Medical physics

authors： Sparks R,Bloch BN,Feleppa E,Barratt D,Moses D,Ponsky L,Madabhushi A

更新日期：2015-03-01 00:00:00

abstract：INTRODUCTION:Ultrasound (US) guidance of the prostate has long been conducted using a transabdominal (TA) approach. More recently, a transperineal (TP) approach has been made available for image guidance. Our aim was to determine if both methods produced similar alignments within the same patients. MATERIALS AND METHO...

journal_title：Medical physics

authors： Szegedi M,Boehm C,Paxton A,Rassiah-Szegedi P,Sarkar V,Zhao H,Su F,Kokeny KE,Lloyd S,Tward J,Salter BJ

更新日期：2020-12-01 00:00:00

abstract：:A method for the in vivo determination of the isocenter dose, Diso, and mid-plane dose, Dm, using the transmitted signal St measured by 25 central pixels of an aSi-based EPID is here reported. The method has been applied to check the conformal radiotherapy of pelvic tumors and supplies accurate in vivo dosimetry avoid...

journal_title：Medical physics

authors： Piermattei A,Fidanzio A,Stimato G,Azario L,Grimaldi L,D'Onofrio G,Cilla S,Balducci M,Gambacorta MA,Di Napoli N,Cellini N

更新日期：2006-11-01 00:00:00

abstract：:Radiation sensitive gels have been used as dosimeters for clinical dose verification of different radiation therapy modalities. However, the use of gels is not widespread, because careful techniques are required to achieve the dose precision and accuracy aimed for in clinical dose verification. Here, the introduction ...

journal_title：Medical physics

authors： Crescenti RA,Scheib SG,Schneider U,Gianolini S

更新日期：2007-04-01 00:00:00

abstract：:This paper examines statistical errors in the measurement of arterial stenoses by digital videodensitometry. Images of vessel phantoms were acquired using digital subtraction angiographic techniques with low concentrations of an iodine contrast medium and low levels of x-ray exposure. Effects of the spatial and tempor...

journal_title：Medical physics

authors： Wright GA,Taylor KW,Rowlands JA

更新日期：1985-11-01 00:00:00

abstract：:A new radiographic patient positioning technique developed for radiosurgery has been analyzed to show the effect of computed tomography (CT) slice thickness on the precision of target localization during treatment. The positioning technique establishes the pose of the patient's anatomy during treatment by comparing tr...

journal_title：Medical physics

authors： Murphy MJ

更新日期：1999-02-01 00:00:00

abstract：PURPOSE:In this study the Octavius detector 729 ionization chamber (IC) array with the Octavius 4D phantom was characterized for flattening filter (FF) and flattening filter free (FFF) static and rotational beams. The device was assessed for verification with FF and FFF RapidArc treatment plans. METHODS:The response o...

journal_title：Medical physics

authors： McGarry CK,O'Connell BF,Grattan MW,Agnew CE,Irvine DM,Hounsell AR

更新日期：2013-09-01 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：PURPOSE:The goals of stereotactic radiosurgery (SRS) are the ablation of target tissue and sparing of critical normal tissue. We develop tools to aid in the selection of collimation and prescription (Rx) isodose line to optimize the dose gradient for single isocenter intracranial stereotactic radiosurgery (SRS) with Ga...

journal_title：Medical physics

authors： Sheth N,Chen Y,Yang J

更新日期：2012-06-01 00:00:00

abstract：:We are evaluating the usefulness of stereomammography in improving breast cancer diagnosis. One area that we are investigating is whether the improved depth perception associated with stereomammography might be significantly enhanced with the use of a virtual 3D cursor. A study was performed to evaluate the accuracy o...

journal_title：Medical physics

authors： Goodsitt MM,Chan HP,Hadjiiski L

更新日期：2000-06-01 00:00:00

abstract：PURPOSE:To evaluate if the recently described problems with the calibration of jaws at Varian linear accelerators can be detected with the DAVID system. METHODS:Recently Varian Clinac field size issues resulted in a widespread medical device correction notice, stating that incorrect jaw positioning due to excessive co...

journal_title：Medical physics

authors： Poppe B,Looe H,Harder D

更新日期：2012-06-01 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:To develop a novel system for patient-specific combined optimization of couch, collimator, and gantry angles for use in volumetric modulated arc therapy (VMAT) treatment planning. The system was designed to produce highly compact dose distributions by extensively sampling the 4π space. Automated fixed couch tra...

journal_title：Medical physics

authors： MacDonald RL,Syme A,Little B,Ward L,Thomas CG

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:Having been overlooked for many years, research is now starting to take into account the directional distribution of neutron workplace fields. Existing neutron dosimetry instrumentation does not account for this directional distribution, resulting in conservative estimates of dose in neutron workplace fields (b...

journal_title：Medical physics

authors： Balmer MJ,Gamage KA,Taylor GC

更新日期：2016-11-01 00:00:00

abstract：:In intensity modulated radiation treatments (IMRT), the position of the field edges and the modulation within the beam are often achieved with a multileaf collimator (MLC). During the MLC calibration process, due to the finite accuracy of leaf position measurements, a systematic error may be introduced to leaf positio...

journal_title：Medical physics

authors： Parent L,Seco J,Evans PM,Dance DR,Fielding A

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:To investigate the optimal use of XR-RV3 GafChromic(®) films to assess patient skin dose in interventional radiology while addressing the means to reduce uncertainties in dose assessment. METHODS:XR-Type R GafChromic films have been shown to represent the most efficient and suitable solution to determine patie...

journal_title：Medical physics

authors： Farah J,Trianni A,Ciraj-Bjelac O,Clairand I,De Angelis C,Delle Canne S,Hadid L,Huet C,Jarvinen H,Negri A,Novák L,Pinto M,Siiskonen T,Waryn MJ,Knežević Ž

更新日期：2015-07-01 00:00:00

abstract：PURPOSE:The aim of this study was to implement a Dirichlet process mixture (DPM) model for automatic tumor edge identification on (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) images by optimizing the parameters on which the algorithm depends, to validate it experimentally, and to test its robus...

journal_title：Medical physics

authors： Giri MG,Cavedon C,Mazzarotto R,Ferdeghini M

更新日期：2016-05-01 00:00:00

abstract：:The physical characteristics of the interactions of megavoltage photons and electrons with matter provide distinct advantages, relative to low-energy (orthovoltage) x rays, that lead to better radiation dose distributions in patients. Use of these high-energy radiations has resulted in better patient care, which has b...

journal_title：Medical physics

authors： Das IJ,Kase KR

更新日期：1992-07-01 00:00:00