Abstract：
:We have developed an analytic solution for spatially resolved diffuse reflectance within the deltaP1 approximation to the radiative transport equation for a semi-infinite homogeneous turbid medium. We evaluate the performance of this solution by comparing its predictions with those provided by Monte Carlo simulations and the standard diffusion approximation. We demonstrate that the delta-P1 approximation provides accurate estimates for spatially resolved diffuse reflectance in both low and high scattering media. We also develop a multi-stage nonlinear optimization algorithm in which the radiative transport estimates provided by the delta-P1 approximation are used to recover the optical absorption (microa), reduced scattering (micros'), and single-scattering asymmetry coefficients (g1) of liquid and solid phantoms from experimental measurements of spatially resolved diffuse reflectance. Specifically, the delta-P1 approximation can be used to recover microa, micros', and g1 with errors within +/- 22%, +/- 18%, and +/- 17%, respectively, for both intralipid-based and siloxane-based tissue phantoms. These phantoms span the optical property range 4 < (micros' /microa) < 117. Using these same measurements, application of the standard diffusion approximation resulted in the recovery of microa and micros' with errors o f +/- 29% and +/- 25%, respectively. Collectively, these results demonstrate that the delta-P1 approximation provides accurate radiative transport estimates that can be used to determine accurately the optical properties of biological tissues, particularly in spectral regions where tissue may display moderate/low ratios of reduced scattering to absorption (micros'/microa).
journal_name
Med Physjournal_title
Medical physicsauthors
Seo I,Hayakawa CK,Venugopalan Vdoi
10.1118/1.2828184subject
Has Abstractpub_date
2008-02-01 00:00:00pages
681-93issue
2eissn
0094-2405issn
2473-4209journal_volume
35pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:Photon point dose kernels and absorbed fractions were generated in water for the full photon emission spectrum of each radionuclide of interest in nuclear medicine, by simulating the transport of particles using Monte Carlo. The kernels were then fitted to a mathematical expression. Absorbed fractions for point source...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597670
更新日期：1996-05-01 00:00:00
abstract：PURPOSE:To analyze the noise performance of the edge illumination phase-based x-ray imaging technique when applying "single-shot" phase retrieval. The latter consists in applying a sample-specific low-pass filter to the raw data, leading to "hybrid" images in which phase and attenuation contrast are merged with each ot...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14366
更新日期：2020-09-01 00:00:00
abstract：PURPOSE:To investigate the acoustic radiation due to eddy current-cryostat interactions and perform a qualitative analysis on noise reduction methods. METHODS:In order to evaluate the sound pressure level (SPL) of the eddy current induced warm bore wall vibration, a Finite Element (FE) model was created to simulate th...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12261
更新日期：2017-06-01 00:00:00
abstract：:The purpose of this study was to implement the Monte Carlo method for clinical radiotherapy dose calculations. We used the EGS4/BEAM code to obtain the phase-space data for 6-20 MeV electron beams and 4, 6, and 15 MV photon beams for Varian Clinac 1800, 2100C, and 2300CD accelerators. A multiple-source model was used ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598729
更新日期：1999-10-01 00:00:00
abstract：:Proton NMR spectroscopy was applied to quantitate the measurement of total body water/fat distributions in vivo. A special MR protocol was developed to excite a thick slab of tissue and display the magnitude NMR spectrum of the collected response signal. Very short echo time TE (8 ms) and long repetition time TR (4000...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596935
更新日期：1992-01-01 00:00:00
abstract：PURPOSE:We have developed a robust tool for performing volumetric and temporal analysis of nodules from respiratory gated four-dimensional (4D) CT. The method could prove useful in IMRT of lung cancer. METHODS:We modified the conventional graph-cuts method by adding an adaptive shape prior as well as motion informatio...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12690
更新日期：2018-01-01 00:00:00
abstract：PURPOSE:Hypoxia is one of the most important factors influencing clinical outcome after radiotherapy. Improved knowledge of factors affecting the levels and distribution of oxygen within a tumor is needed. The authors constructed a theoretical 3D model based on histological images to analyze the influence of vessel den...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4773886
更新日期：2013-02-01 00:00:00
abstract：:Attenuation correction is an essential component of the long chain of data correction techniques required to achieve the full potential of quantitative positron emission tomography (PET) imaging. The development of combined PET/magnetic resonance imaging (MRI) systems mandated the widespread interest in developing nov...
journal_title：Medical physics
pub_type： 杂志文章,评审
doi：10.1118/1.4941014
更新日期：2016-03-01 00:00:00
abstract：PURPOSE:The pulse line ion accelerator (PLIA) is a low-cost accelerator concept originally designed to accelerate heavy ions. Our group has been investigating the use of PLIA to accelerate light ions and believe a multi-stage PLIA could be useful for short half-life PET isotope production. The goal of this work was to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13875
更新日期：2019-12-01 00:00:00
abstract：:A direct data link between a CT scanner and a radiation treatment planning system has been developed. The link transmits the data serially over a coaxial cable using the pseudo-paper-tape punch and reader (serial PIO) interfaces. The data transmission rate with error-check is approximately 25,000 8-bit bytes/s. This t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594536
更新日期：1979-09-01 00:00:00
abstract：:The calibration and quality control of compensators is conventionally performed with an ion chamber in a water-equivalent phantom. In our center, the compensator factor and four off-axis fluence ratios are measured to verify the central axis beam modulation and orientation of the compensator. Here we report the invest...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1584040
更新日期：2003-07-01 00:00:00
abstract：PURPOSE:To develop a probabilistic treatment planning (PTP) method which is robust to systematic patient setup errors and to compare PTP plans with plans generated using a planning target volume (PTV) margin optimized to give the same target coverage probability as the PTP plan. METHODS:Plans adhering to the RTOG-0126...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3679856
更新日期：2012-02-01 00:00:00
abstract：PURPOSE:The authors are developing a system for calibrated breast density measurements using full field digital mammography (FFDM). Breast tissue equivalent (BTE) phantom images are used to establish baseline (BL) calibration curves at time zero. For a given FFDM unit, the full BL dataset is comprised of approximately ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4903299
更新日期：2015-02-01 00:00:00
abstract：:Functional single photon emission computed tomography (SPECT) images of brain activation are based on a comparison of base line and activation images. The correctness of the functional images depends, among other factors, on the accurate spatial registration (alignment) of the base line and activation image data. The ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597412
更新日期：1994-10-01 00:00:00
abstract：:The computational aspects of the design of an optical distance indicator (ODI) for use with a radiation therapy accelerator are discussed. The specifics of the optical and mechanical design of an ODI for use with a superconducting cyclotron used for fast neutron therapy are presented. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598510
更新日期：1999-02-01 00:00:00
abstract：:A double-mirror multilayer monochromator was developed for the purpose of irradiating live cell cultures at the Synchrotron Radiation Center, University of Wisconsin-Madison. The monochromator is designed for the soft x-ray region with photon energies between 270 and 2400 eV. Multilayer mirrors with 55 bilayers of W/C...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598259
更新日期：1998-05-01 00:00:00
abstract：:The image artifacts characteristic of a scanning chest radiographic system are reviewed. The technique employs a pulsed beam of radiation swept in an overlapping raster pattern that can result in severe ripple and scan line artifacts with improper scanning parameters. A one-dimensional treatment of the scanner geometr...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595492
更新日期：1984-03-01 00:00:00
abstract：:This paper proposes a new respiratory gated radiation treatment system that allows real-time tumor localization while avoiding invasive operation to a patient. The proposed system employs a three-dimensional (3D) ultrasound device, a 3D digital localizer, and a real-time image processing system. At the planning time, ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1634482
更新日期：2004-02-01 00:00:00
abstract：:Age-related macular degeneration (AMD) is a leading cause for vision loss for people over the age of 65 in the United States and a major health problem worldwide. Research for new treatments of the wet form of the disease using kilovoltage stereotactic radiosurgery is currently underway at Oraya Therapeutics, Inc. In ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3168554
更新日期：2009-08-01 00:00:00
abstract：:Administration of x-ray contrast agents during heart catheterization examination increases the absorbed radiation dose in tissue. To estimate the dose absorbed by the blood of children undergoing diagnostic heart catheterization and angiocardiography, a number of measurements and calculations were conducted. First, en...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594613
更新日期：1979-11-01 00:00:00
abstract：:Permanent implantation of 125I (iodine) or 103Pd (palladium) sources is a popular treatment option in the management of early stage prostate cancer. New sources are being developed, some of which are being marketed for different clinical applications. A new technique of adjuvant stereotactic permanent seed breast impl...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3006151
更新日期：2008-12-01 00:00:00
abstract：PURPOSE:To improve image quality and reduce imaging dose in CBCT for radiation therapy applications and to realize near real-time image reconstruction based on use of a fast convergence iterative algorithm and acceleration by multi-GPUs. METHODS:An iterative image reconstruction that sought to minimize a weighted leas...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735747
更新日期：2012-06-01 00:00:00
abstract：:Many new models of 125I seeds are being introduced, mainly due to the increase in prostate seed implants. We have evaluated the SourceTech Medical (STM), model STM1251, 125I seed using thermoluminescent dosimeters (TLDs) in a solid water phantom. TLD cubes, LiF TLD-100, with dimension 1 mm on each edge, were irradiate...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1577251
更新日期：2003-07-01 00:00:00
abstract：:The widespread application of positron emission tomography (PET) in clinical oncology has driven this imaging technology into a number of new research and clinical arenas. Increasing numbers of patient scans have led to an urgent need for efficient data handling and the development of new image analysis techniques to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2432404
更新日期：2007-02-01 00:00:00
abstract：PURPOSE:Cherenkov light during MV radiotherapy has recently found imaging and therapeutic applications but is challenged by relatively low fluence. Our purpose is to investigate the feasibility of increasing Cherenkov light production during MV radiotherapy by increasing photon energy and applying specialized beam-hard...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12927
更新日期：2018-07-01 00:00:00
abstract：:One of the key components in modern LINAC room shielding design is the amount of 90 degrees head leakage radiation levels. With the general clinical acceptance of intensity-modulated radiation therapy (IMRT) technique, accurate knowledge of this quantity has become even more important. Measurement of 90 degrees head l...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2335489
更新日期：2006-09-01 00:00:00
abstract：PURPOSE:The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET∕MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4757911
更新日期：2012-11-01 00:00:00
abstract：PURPOSE:To develop a novel aperture-based algorithm for volumetric modulated are therapy (VMAT) treatment plan optimization with high quality and high efficiency. METHODS:The VMAT optimization problem is formulated as a large-scale convex programming problem solved by a column generation approach. The authors consider...
journal_title：Medical physics
pub_type： 信件
doi：10.1118/1.3491675
更新日期：2010-11-01 00:00:00
abstract：PURPOSE:Lower radiation tolerance of the whole liver hinders dose escalations of stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) treatment. This study was conducted to define the exact doses that result in radiation-induced liver disease (RILD) as well as to determine dose constraints for t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4953831
更新日期：2016-07-01 00:00:00
abstract：PURPOSE:The aim of this study was to develop a dose calculation method which is applicable to the interseed attenuation and the geometry lacking the equilibrium radiation scatter conditions in brachytherapy. METHODS:The dose obtained from measurement with a radiophotoluminescent glass rod dosimeter (GRD) was compared ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3590370
更新日期：2011-06-01 00:00:00
