A5051201377- Radiation Dose and Imaging
- Advanced Radiotherapy Techniques
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- Radiation Therapy and Dosimetry
- Digital Radiography and Breast Imaging
- Radioactivity and Radon Measurements
- Radiation Detection and Scintillator Technologies
- Radiation Shielding Materials Analysis
- Radiopharmaceutical Chemistry and Applications
- Nuclear reactor physics and engineering
- Graphite, nuclear technology, radiation studies
- Nuclear and radioactivity studies
- Radioactive Decay and Measurement Techniques
- Nuclear Physics and Applications
- Ocular and Laser Science Research
- Photoacoustic and Ultrasonic Imaging
- Radiology practices and education
- Effects of Radiation Exposure
- Radiation Effects and Dosimetry
- Electromagnetic Fields and Biological Effects
- Cardiac Imaging and Diagnostics
- Radioactive contamination and transfer
- Infrared Thermography in Medicine
- Intraocular Surgery and Lenses
Helmholtz Zentrum München
2013-2022
Center for Environmental Health
2004-2014
Universidad Politécnica de Madrid
2014
Institute of Groundwater Ecology
2004-2013
Federal Office for Radiation Protection
1999-2010
UCLA Medical Center
2010
Université Toulouse III - Paul Sabatier
2008
München Klinik
2006
Deutsches Herzzentrum München
2006
Institute of Semitic Studies
2006
Multislice computed tomography angiography (CTA) is a promising technology for imaging patients with suspected coronary artery disease. Compared 16-slice CTA, the improved spatial and temporal resolution of 64-slice CTA (0.6- versus 1.0-mm slice thickness 330- 420-ms gantry rotation time) associated an increase in radiation dose. The objective this retrospective investigation was to compare estimated dose received during 16- daily practice investigate impact different scan protocols on image...
PREFACE MAIN POINTS EXECUTIVE SUMMARY 1. INTRODUCTION 2. Quantities used in radiation protection for external exposure 3. Determination of organ absorbed doses OF the ICRP/ICRU REFERENCE phantomS 4. Conversion coefficients 5. Relationships between dose conversion For operational and quantities References Annex A - Effective B Organ photons C neutrons D Skeletal fluence-to-dose response functions Photons E Neutrons F eye lens G Special considerations assessing local skin equivalent H superior...
Purpose: A recent work has demonstrated the feasibility of estimating dose to individual organs from multidetector CT exams using patient‐specific, scanner‐independent ‐to‐organ‐dose conversion coefficients. However, previous study only investigated organ a single patient model full‐body helical scan. The purpose this was extend validity estimation technique patients any size undergoing common clinical exam. This done by determining influence on coefficients generated for typical abdominal...
Monte Carlo radiation transport techniques have made it possible to accurately estimate the dose radiosensitive organs in patient models from scans performed with modern multidetector row computed tomography (MDCT) scanners. However, there is considerable variation organ doses across scanners, even when similar acquisition conditions are used. The purpose of this study was investigate feasibility a technique that would be scanner independent. This accomplished by assessing ability CTDIvol...
Dose coefficients for assessment of internal exposures to radionuclides are radiological protection quantities giving either the organ equivalent dose or effective per intake radionuclide following ingestion inhalation. In International Commission on Radiological Protection’s (ICRP) Occupational Intakes Radionuclides (OIR) publication series, new biokinetic models distribution internalised in human body presented as needed establishing time-integrated activity within organs deposition...
New organ equivalent dose conversion coefficients are presented for whole body irradiation with monoenergetic photons of energies between 10 keV and MeV idealized geometries seven adult male female voxel models. The broad parallel photon beams in anterior–posterior, posterior–anterior, left- right-lateral direction a full 360° rotation around the length axis. Dose differences different models below approximately 30% some organs energy range 60 200 keV, but they can be up to 100% or more...
The purpose of this work is to examine the effects patient size on radiation dose from CT scans. To perform these investigations, we used Monte Carlo simulation methods with detailed models both patients and multidetector computed tomography (MDCT) scanners. A family three-dimensional, voxelized previously developed validated by GSF was implemented as input files using code MCNPX. These represent a range sizes ages (8 weeks 48 years) have all radiosensitive organs identified segmented,...
Non-invasive coronary angiography by multislice spiral computed tomography (MSCT) is a promising method for the diagnosis of artery disease (CAD). However, clinical role this has not been established specific patient cohorts. Therefore, objective current prospective, blinded study was to investigate diagnostic value MSCT in patients with an intermediate pre-test probability having CAD when compared invasive angiography.A total 243 were asked undergo 16- or 64-slice CT before planned from 12...
Backscatter factors were determined for x-ray beams relevant to diagnostic radiology using Monte Carlo methods. The phantom size considered most suitable calibration of dosimeters is a cuboid front surface and 15 cm depth. This also provides good approximation adult patients. Three different media studied: water, PMMA ICRU tissue; the source geometry was point with varying field source-to-phantom distance. variations backscatter factor medium examined. From obtained data, set selected...
In recent years, several papers dealing with the eye lens dose have been published, because epidemiological studies implied that induction of cataracts occurs even at doses less than 500 mGy. Different questions were addressed: Which personal equivalent quantity is appropriate for monitoring to lens? Is a new definition H(p)(3) based on cylinder phantom represent human head necessary? Are current conversion coefficients from fluence sufficiently accurate? To investigate latter question,...
Recent epidemiological studies suggest a rather low dose threshold (below 0.5 Gy) for the induction of cataract eye lens. Some other even assume that there is no at all. Therefore, protection measures have to be optimized and current limits lens may reduced in future. Two questions arise from this situation: first, which quantity related risk developing cataract, second, personal equivalent appropriate monitoring quantity. While Hp(0.07) has often been seen as being sufficiently accurate...
Over the past decades, significant improvements have been made in field of computational human phantoms (CHPs) and their applications biomedical engineering. Their sophistication has dramatically increased. The very first CHPs were composed simple geometric volumes, e.g., cylinders spheres, while current a high resolution, cover substantial range patient population, anatomical accuracy, are poseable, morphable, augmented with various details to perform functionalized computations. Advances...
This paper describes the construction of three adult female voxel models, two whole-body and one from head to thighs, computed tomographic data 3 women different stature. Voxel models (also called phantoms) are human based on or magnetic resonance images obtained high resolution continuous scans a single individual. The gray-scale information content medical interpreted into tissues (i.e., organs), process known as segmentation. phantoms, consisting millions volume elements, voxels, provide...
A new series of organ equivalent dose conversion coefficients for whole body external photon exposure is presented a standardized couple human voxel models, called Rex and Regina. Irradiations from broad parallel beams in antero-posterior, postero-anterior, left- right-side lateral directions as well 360 degrees rotational source have been performed numerically by the Monte Carlo transport code EGSnrc. Dose an isotropically distributed were computed, too. The models Regina originating real...
The authors present results obtained at Neuherberg since 1984 during studies of the development mathematical CT 3D phantoms based on scan slices children, adults and Alderson Rando dosimetry phantom. (U.K.).
For the forthcoming update of organ dose conversion coefficients, International Commission on Radiological Protection (ICRP) will use voxel-based computational phantoms due to their improved anatomical realism compared with class mathematical or stylized used previously. According ICRP philosophy, these should be representative male and female reference adults respect external dimensions, topology masses. To meet requirements, models an adult have been constructed at GSF, based existing...
The fluence to organ-dose and effective-dose conversion coefficients for neutrons protons with energies up 100 GeV was calculated using the PHITS code coupled male female adult reference computational phantoms, which are be released as a common ICRP/ICRU publication. For calculation, radiation tissue weighting factors, wR wT, respectively, revised in ICRP Publication 103 were employed. effective dose equivalents derived quality factors of both Q(L) Q(y) relationships also estimated,...