Abstract:
:Radiation dose calculations in nuclear medicine depend on quantification of activity via planar and/or tomographic imaging methods. However, both methods have inherent limitations, and the accuracy of activity estimates varies with object size, background levels, and other variables. The goal of this study was to evaluate the limitations of quantitative imaging with planar and single photon emission computed tomography (SPECT) approaches, with a focus on activity quantification for use in calculating absorbed dose estimates for normal organs and tumors. To do this we studied a series of phantoms of varying complexity of geometry, with three radionuclides whose decay schemes varied from simple to complex. Four aqueous concentrations of ⁹⁹mTc, ¹³¹I, and ¹¹¹In (74, 185, 370, and 740 kBq mL⁻¹) were placed in spheres of four different sizes in a water-filled phantom, with three different levels of activity in the surrounding water. Planar and SPECT images of the phantoms were obtained on a modern SPECT/computed tomography (CT) system. These radionuclides and concentration/background studies were repeated using a cardiac phantom and a modified torso phantom with liver and "tumor" regions containing the radionuclide concentrations and with the same varying background levels. Planar quantification was performed using the geometric mean approach, with attenuation correction (AC), and with and without scatter corrections (SC and NSC). SPECT images were reconstructed using attenuation maps (AM) for AC; scatter windows were used to perform SC during image reconstruction. For spherical sources with corrected data, good accuracy was observed (generally within ±10% of known values) for the largest sphere (11.5 mL) and for both planar and SPECT methods with ⁹⁹mTc and ¹³¹I, but were poorest and deviated from known values for smaller objects, most notably for ¹¹¹In. SPECT quantification was affected by the partial volume effect in smaller objects and generally showed larger errors than the planar results in these cases for all radionuclides. For the cardiac phantom, results were the most accurate of all of the experiments for all radionuclides. Background subtraction was an important factor influencing these results. The contribution of scattered photons was important in quantification with ¹³¹I; if scatter was not accounted for, activity tended to be overestimated using planar quantification methods. For the torso phantom experiments, results show a clear underestimation of activity when compared to previous experiment with spherical sources for all radionuclides. Despite some variations that were observed as the level of background increased, the SPECT results were more consistent across different activity concentrations. Planar or SPECT quantification on state-of-the-art gamma cameras with appropriate quantitative processing can provide accuracies of better than 10% for large objects and modest target-to-background concentrations; however when smaller objects are used, in the presence of higher background, and for nuclides with more complex decay schemes, SPECT quantification methods generally produce better results.
journal_name
Health Physjournal_title
Health physicsauthors
Pereira JM,Stabin MG,Lima FR,Guimarães MI,Forrester JWdoi
10.1097/HP.0b013e3181e28cdbsubject
Has Abstractpub_date
2010-11-01 00:00:00pages
688-701issue
5eissn
0017-9078issn
1538-5159pii
00004032-201011000-00011journal_volume
99pub_type
杂志文章相关文献
HEALTH PHYSICS文献大全abstract::In the assessment of risk, several factors affect predictions: selection of reactive agent, selection of tumor incidence data, modeling of dose, scaling across species, adjustment for differences in duration and frequency of exposure, and selection of the most suitable risk extrapolation model. If the endpoints, expos...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198907001-00046
更新日期:1989-01-01 00:00:00
abstract::CR-39 plastic was attached to household glass objects to learn whether residual radioactivity from radon decay products could be measured and correlated with cumulative radon exposures over defined time periods. Such an approach could be used to increase the completeness of exposure data collected in epidemiologic stu...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199304000-00005
更新日期:1993-04-01 00:00:00
abstract::The Human Monitoring Laboratory has replaced its lung counting system with four large area (85 mm x 30 mm) HPGe detectors, electronics, and software. The system has been calibrated with the same lung set and phantom that was used to calibrate the Human Monitoring Laboratory's previous lung counting system and the Came...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.hp.0000167148.87179.b7
更新日期:2005-10-01 00:00:00
abstract::Haemopoietic stem cell assays allow investigation of local radiation damage at any time after contamination. These techniques were used to determine the relative effectiveness of 241Am and 226Ra in inducing damage in various cortical and trabecular bone marrow sites. Male Balb/c mice were injected with either 230 or 6...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198306001-00054
更新日期:1983-01-01 00:00:00
abstract::A high-pressure ion chamber filled with 2.5825 X 10(5) kg m-2 argon as used to measure the dose rates of several sites of interest in an attempt to evaluate the dose rates contributed by cosmic rays. Observation sites included two water reservoirs deeper than 110 m, Mount Ali which is higher than 2500 m, airliners fly...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198703000-00009
更新日期:1987-03-01 00:00:00
abstract::Diagnostic radiology dosimeters should comply with International Electrotechnical Commission (IEC) 61674 standard in order to perform measurements with sufficient accuracy and reliability. The calibration of a dosimeter is performed under, and pertains to, reference conditions. However, in most cases, dosimeters are u...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0b013e3181d18d45
更新日期:2010-05-01 00:00:00
abstract::To elucidate any connection between high radon concentrations and low-infiltration houses, we have concurrently measured the 222Rn concentration and the infiltration rate in U.S. houses. Three housing surveys have been undertaken: one in "energy-efficient" houses located throughout the U.S. and two in "conventional" h...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198308000-00014
更新日期:1983-08-01 00:00:00
abstract::Acute radiation syndrome represents the clinical response of radiation-sensitive key tissues (i.e., hematopoietic, gastrointestinal and neurovascular) following exposure to high doses of ionizing radiation. In this context, the hematopoietic syndrome remains the first therapeutic challenge. Today, identifying new drug...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/HP.0000000000000039
更新日期:2014-06-01 00:00:00
abstract::When measuring radioactivity, the problem rises of deciding whether or not a sample contains radioactivity in excess of background and above which value the result is meaningful. This decision process is why the notion of decision level was introduced. Whereas there is unanimity about its definition, this is not the c...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/00004032-200308000-00002
更新日期:2003-08-01 00:00:00
abstract::The operational radiation protection issues associated with the Z-Machine accelerator located at Sandia National Laboratories are large: a variety of materials can be placed into the machine; these materials can be subjected to a variety of nuclear reactions, producing a variety of activation products. Without full un...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.HP.0000253937.78314.e6
更新日期:2007-02-01 00:00:00
abstract::The movement through the environment and the toxicity to plants of 99Tc have been studied. However, information is scanty on 99Tc toxicity to mammals even though this is the decisive criterion for assessing the consequences of releases of Tc. A critical tissue could be the thyroid because of its preferential accumulat...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198908000-00014
更新日期:1989-08-01 00:00:00
abstract::Absorbed dose and dose equivalent conversion coefficients are routinely used in personnel dosimetry programs. These conversion coefficients can be applied to particle fluences or to measured air kerma values to determine appropriate operational monitoring quantities such as the ambient dose equivalent or personal dose...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.HP.0000243165.43316.78
更新日期:2007-02-01 00:00:00
abstract::The Medical University of South Carolina is currently participating in clinical trials of 131I radiolabeled Anti-B1 antibody for treatment of Non-Hodgkin's lymphoma. Under current South Carolina Department of Health and Environmental Control regulatory guidelines,; these patients are required to be admitted to the hos...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-200011001-00004
更新日期:2000-11-01 00:00:00
abstract::This paper describes an investigation into the distribution of radiation doses to workers, undertaken at the request of ICRP Committee 4. Three main questions are considered. Firstly, the distribution of annual doses to workers is described. Doses are generally well below the ICRP dose limits and most are below 15 mSv...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198611000-00002
更新日期:1986-11-01 00:00:00
abstract::The PATHWAY model results were used, in conjunction with a hypothetical major nuclear attack on the U.S., to arrive at the ratio of internal to external dose for humans from early (48 h) fallout. Considered were the four nuclides (137Cs, 89Sr, 90Sr, 131I) that account for most of the reconstructed whole-body committed...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199201000-00004
更新日期:1992-01-01 00:00:00
abstract::Eight of the most severe cases of acute radiation disease (ARS) known to have occurred in humans (as the result of criticality accidents) had survival times less than 120 h (herein defined as "early death"). These accidents were analyzed and are discussed with respect to the specific accident scenarios and the resulti...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0b013e31823b4b78
更新日期:2012-04-01 00:00:00
abstract::Fetal radiation dose estimates were calculated for women who received oral administrations of 59Fe at Vanderbilt University in the 1940's. A similar dosimetry analysis was performed by Dyer and Brill in 1972; the availability of recently developed physical models of the pregnant female at different stages of gestation...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199705000-00004
更新日期:1997-05-01 00:00:00
abstract::By testing industry standard techniques for radon progeny evaluation on air sample filters, a new technique is developed to evaluate transuranic activity on air filters by curve fitting the decay curves. The industry method modified here is simply the use of filter activity measurements at different times to estimate ...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-200401000-00010
更新日期:2004-01-01 00:00:00
abstract::Many governmental and non-governmental agencies are involved in the planning for radiation events in the U.S. We will focus on medical management after mass casualty events, specifically the involvement of the Radiation Injury Treatment Network (RITN), a voluntary consortium of medical centers across the continental U...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.HP.0000346701.04476.0d
更新日期:2010-06-01 00:00:00
abstract::This document was prepared as a review of the current knowledge of tritium metabolism and dosimetry. The physical, chemical, and metabolic characteristics of various forms of tritium are presented as they pertain to performing dose assessments for occupational workers and for the general public. For occupational worke...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/00004032-199312000-00003
更新日期:1993-12-01 00:00:00
abstract::Self-evacuation by a private vehicle is one of the most commonly used methods of public evacuation in the case of a nuclear accident. The aim of this paper is to evaluate the dose-reduction effects of vehicles. To achieve this aim, a model for calculating the dose reduction factor was developed based on the actual sha...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000000729
更新日期:2018-01-01 00:00:00
abstract::The radionuclide vector in the release plume from the destroyed unit 4 of the Chernobyl Nuclear Power Plant was assessed. Emphasis was laid on radionuclides relevant for the internal dose, including those with short half-lives, and on the radionuclide vector in the 30-km zone where practically no data in air or foodst...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-200202000-00002
更新日期:2002-02-01 00:00:00
abstract::Radiopharmaceutical therapy involves the use of radionuclides that are either conjugated to tumor-targeting agents (e.g., nanoscale constructs, antibodies, peptides, and small molecules) or that concentrate in tumors through natural physiological mechanisms that occur predominantly in neoplastic cells. In the latter c...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000001000
更新日期:2019-02-01 00:00:00
abstract::The aims of this study were to develop and improve the sensitivity of an electron spin resonance (ESR) spectrometer and to demonstrate its functionality for dosimetry in measuring ESR signals from radiation-exposed fingernails. The newly-developed spectrometer was a lightweight (22 kg) one-box ESR device with a resona...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.HP.0000348019.70058.a0
更新日期:2010-02-01 00:00:00
abstract::Just two years have passed since the Tokyo Electric Power Company-Fukushima Daiichi Nuclear Power Plant (NPP) accident, a multidimensional disaster that combined to destroy the local infrastructure on which the safety system depended and gave a serious impact to the world. Countermeasures including evacuation, shelter...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000000007
更新日期:2014-02-01 00:00:00
abstract::This paper provides a review and reanalysis of data relating to gastrointestinal (GI) uptake of uranium in humans. Estimates of GI uptake of uranium in adult humans have been derived from results of three controlled experimental studies involving short-term oral intake of an elevated quantity of uranium in fluids, fro...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/00004032-199504000-00005
更新日期:1995-04-01 00:00:00
abstract::DOE facilities are required to conduct environmental surveillance to verify that facility operations are operated within the approved risk envelope and have not caused undue risk to the public and the environment. Given a reduced budget, a strategy for analyzing environmental surveillance data was developed to set pri...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199711000-00012
更新日期:1997-11-01 00:00:00
abstract::The variability in radiosensitivity across the human population is governed in part by genetic factors. The ability to predict therapeutic response, identify individuals at greatest risk for adverse clinical responses after therapeutic radiation doses, or identify individuals at high risk for carcinogenesis from envir...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/HP.0b013e3182692085
更新日期:2012-11-01 00:00:00
abstract::Twenty-six white male workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions. Their effective doses range from 0.1 to 7.2 Sv with a median value of 1.25 Sv. As of the e...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199710000-00004
更新日期:1997-10-01 00:00:00
abstract::A recent publication by in the April 28, 2004, issue of JAMA raises concern since it suggests that exposure to dental x rays during pregnancy could be responsible for human fetal growth retardation. Furthermore, the article could have a negative impact on the dental care of pregnant women who might fear the effect of ...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.hp.0000152109.40007.35
更新日期:2005-04-01 00:00:00