Patient radiation doses during cardiac catheterization procedures.
TL;DR: The objective of the present project was the determination of the dose received by patients during cardiac procedures, such as coronary angiography, percutaneous transluminal coronary angioplasty (PTCA) and stent implantation, which showed the contribution of cinefluorography to the total DAP was higher than that of fluoroscopy.
Abstract: The objective of the present project was the determination of the dose received by patients during cardiac procedures, such as coronary angiography, percutaneous transluminal coronary angioplasty (PTCA) and stent implantation. Thermoluminescent dosemeters (TLDs), suitably calibrated, were used for the measurement of the dose received at four anatomical locations on the patient's skin. A dose-area product (DAP) meter was also used. The contribution of cinefluorography to the total DAP was higher than that of fluoroscopy. A DAP to effective dose conversion factor equal to 0.183 mSv Gy-1 cm-2 was estimated with the help of a Rando phantom. Thus, the effective dose received by the patients could be assessed. Mean values of effective dose equal to 5.6 mSv, 6.9 mSv, 9.3 mSv, 9.0 mSv and 13.0 mSv were estimated for coronary angiography, PTCA, coronary angiography and ad hoc PTCA, PTCA followed by stent implantation and coronary angiography and ad hoc PTCA followed by stent implantation, respectively.
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01 Jan 2000
TL;DR: This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices, in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation.
Abstract: NOTE The report of the Committee without its annexes appears as Official Records of the General Assembly, Sixty-third Session, Supplement No. 46. The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The country names used in this document are, in most cases, those that were in use at the time the data were collected or the text prepared. In other cases, however, the names have been updated, where this was possible and appropriate, to reflect political changes. Scientific Annexes Annex A. Medical radiation exposures Annex B. Exposures of the public and workers from various sources of radiation INTROdUCTION 1. In the course of the research and development for and the application of atomic energy and nuclear technologies, a number of radiation accidents have occurred. Some of these accidents have resulted in significant health effects and occasionally in fatal outcomes. The application of technologies that make use of radiation is increasingly widespread around the world. Millions of people have occupations related to the use of radiation, and hundreds of millions of individuals benefit from these uses. Facilities using intense radiation sources for energy production and for purposes such as radiotherapy, sterilization of products, preservation of foodstuffs and gamma radiography require special care in the design and operation of equipment to avoid radiation injury to workers or to the public. Experience has shown that such technology is generally used safely, but on occasion controls have been circumvented and serious radiation accidents have ensued. 2. Reviews of radiation exposures from accidents have been presented in previous UNSCEAR reports. The last report containing an exclusive chapter on exposures from accidents was the UNSCEAR 1993 Report [U6]. 3. This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices. Its conclusions are to be seen in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation. 4. The Committee's evaluations of public, occupational and medical diagnostic exposures are mostly concerned with chronic exposures of …
3,924 citations
TL;DR: Effective dose provides an approximate indicator of potential detriment from ionizing radiation and should be used as one parameter in evaluating the appropriateness of examinations involving ionizing Radiation.
Abstract: Medical uses of radiation have grown very rapidly over the past decade, and, as of 2007, medical uses represent the largest source of exposure to the U.S. population. Most physicians have difficulty assessing the magnitude of exposure or potential risk. Effective dose provides an approximate indicator of potential detriment from ionizing radiation and should be used as one parameter in evaluating the appropriateness of examinations involving ionizing radiation. The purpose of this review is to provide a compilation of effective doses for radiologic and nuclear medicine procedures. Standard radiographic examinations have average effective doses that vary by over a factor of 1000 (0.01-10 mSv). Computed tomographic examinations tend to be in a more narrow range but have relatively high average effective doses (approximately 2-20 mSv), and average effective doses for interventional procedures usually range from 5-70 mSv. Average effective dose for most nuclear medicine procedures varies between 0.3 and 20 mSv. These doses can be compared with the average annual effective dose from background radiation of about 3 mSv.
1,736 citations
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...Nippon Igaku Hoshasen Gakkai Zasshi 1995;55(11):763–768....
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TL;DR: Physicians ordering and performing cardiac imaging should be very familiar with the dosage of radiation from cardiac diagnostic tests and ways in which dose can be minimized, including nuclear scintigraphy, CT for calcium scoring and coronary angiography (CTCA), and conventional coronary angIography (CCA).
Abstract: The volume of cardiac diagnostic procedures involving the use of ionizing radiation has increased rapidly in recent years. Whereas in 1990, fewer than 3 million nuclear cardiology studies were performed in the United States, by 2002 this figure more than tripled to 9.9 million.1 Cardiac computed tomographic (CT) volume doubled between 2002 and 2003, to 485 000 cases,2 and has continued to grow since then. The volume of procedures performed in cardiac catheterization labs increased from 2.45 million in 1993 to 3.85 million in 2002.3
The powerful diagnostic and risk-stratification data provided by these procedures play a central role in clinical cardiology and have contributed to the decrease in morbidity and mortality from coronary heart disease. Nevertheless, performance of any diagnostic test requires a careful assessment of the risks and benefits of the test and optimization of protocols to minimize risks to patients, staff members, and the public. Procedures that utilize ionizing radiation should be performed in accordance with the As Low As Reasonably Achievable (ALARA) philosophy. Thus, physicians ordering and performing cardiac imaging should be very familiar with the dosage of radiation from cardiac diagnostic tests and ways in which dose can be minimized. In this report we discuss the measurement of radiation and the dosimetry of commonly performed cardiac diagnostic imaging tests, including nuclear scintigraphy, CT for calcium scoring and coronary angiography (CTCA), and conventional coronary angiography (CCA). For each modality, we address the terminology and methodology used to quantify radiation received by patients, doses to patients with typical protocols, and dose-reduction techniques.
Biological effects of ionizing radiation can be classified as deterministic or stochastic. Deterministic effects such as skin injuries and cataract formation occur predictably when dose exceeds a certain threshold, whereas stochastic effects such as cancer incidence and germ cell mutations occur with …
792 citations
TL;DR: PGT coronary CT angiography offers improved image quality and substantially reduced effective radiation dose compared with traditional RGH coronary CTAngiography.
Abstract: Purpose: To retrospectively compare image quality, radiation dose, and blood vessel assessability for coronary artery computed tomographic (CT) angiograms obtained with a prospectively gated transverse (PGT) CT technique and a retrospectively gated helical (RGH) CT technique. Materials and Methods: This HIPAA-compliant study received a waiver for approval from the institutional review board, including one for informed consent. Coronary CT angiograms obtained with 64–detector row CT were retrospectively evaluated in 203 clinical patients. A routine RGH technique was evaluated in 82 consecutive patients (44 males, 38 females; mean age, 55.6 years). The PGT technique was then evaluated in 121 additional patients (71 males, 50 females; mean age, 56.7 years). All images were evaluated for image quality, estimated radiation dose, and coronary artery segment assessability. Differences in image quality score were evaluated by using a proportional odds logistic regression model, with main effects for three readers...
538 citations
TL;DR: Multislice spiral computed tomography has shortcomings difficult to overcome in daily practice and, at the more clinically relevant per-patient analysis, continues to have moderate specificity in patients with high prevalence of CAD.
475 citations
References
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TL;DR: Percutaneous transluminal coronary angioplasty appears to be an effective alternative to coronary artery bypass surgery in patients whose coronary artery anatomy is suitable--that is, an individual with single vessel coronary artery disease whose stenoses are proximal, discrete, subtotal, concentric and noncalcified.
Abstract: Percutaneous transluminal coronary angioplasty appears to be an effective alternative to coronary artery bypass surgery in patients whose coronary artery anatomy is suitable--that is, an individual with single (or, at most, double) vessel coronary artery disease whose stenoses are proximal, discrete, subtotal, concentric and noncalcified. Since emergent coronary artery bypass surgery is required in 5% to 7% of patients even when angioplasty is attempted by an experienced physician, the patient should be an acceptable candidate for surgery from both a cardiac and noncardiac standpoint. Unfortunately, ideal angioplasty candidates are a distinct minority among those with coronary artery disease. If the procedure is reserved for ideal (or nearly ideal) candidates, the rate of success should approach 75% to 80%, and the incidence of major complications should be below 10%. Although the procedure appears to be effective in alleviating angina, it is unlikely that it will exert a beneficial effect on survival when compared to either medical therapy or coronary artery bypass surgery.
482 citations
TL;DR: Dose-area product and, when feasible, surface dose using thermoluminescent dosimetry chips were measured and both approaches are discussed, as well as their potential use in patient protection programmes.
Abstract: Large exposures incurred in interventional radiology procedures make it advisable to establish reference dose values. These dose values should be quoted in quantities representative of the radiological risk to the patient. In Spain, measurement methods were developed to comply with the European Directive on Patient Protection. Dose-area product and, when feasible, surface dose using thermoluminescent dosimetry chips were measured. Both approaches are discussed, as well as their potential use in patient protection programmes. Initial results are presented for a sample of 680 patients in 10 hospital centres in Spain. Mean, median and range are reported for some specific procedures. Mean values of 8750, 6651, 6663, 9292 and 6816 cGy cm2 are reported for percutaneous transluminal coronary angioplasty, coronary angiography, low extremity, renal and cerebral arteriographies, respectively.
135 citations
Journal Article•
TL;DR: A scheme for performing this type of calculation for generating quantitative risk estimates in the field of diagnostic radiology is proposed.
Abstract: The Rando is a commercially available anthropomorphic phantom, marketed by Alderson Research Laboratories in the United States and widely used for obtaining detailed dose distributions in external beam radiotherapy. To obtain a mean organ dose it is necessary to combine the Rando anatomical data with experimentally determined dose distributions within the phantom. The purpose of this paper is to propose a scheme for performing this type of calculation for generating quantitative risk estimates in the field of diagnostic radiology.
102 citations
TL;DR: It was deduced from the results of the study that the radiologist may expect to receive a mean dose above the lead apron at chest height of 11 microSV and 25 microSv per examination when performing cerebral angiography and arterial embolization, respectively.
Abstract: Cerebral angiography provides valuable information for use in the clinical management of patients but can result in relatively high radiation doses to patients and staff due to the extended fluoroscopy time and number of images acquired during an examination. In this study, extremity doses to radiologists and scrub nurses working in a neuroradiological centre were monitored during a 3 month period using thermoluminescent dosemeters (TLDs). Electronic personal dosemeters were also used to monitor doses above the lead apron at chest height to the radiologists, radiographers and the scrub nurses. Patient doses were recorded using a dose-area product meter whilst patient thyroid dose was measured using TLDs. Two types of examination were studied: cerebral angiography and arterial embolization. It was deduced from the results of the study that the radiologist may expect to receive a mean dose above the lead apron at chest height of 11 uSv and 25 uSv per examination when performing cerebral angiography and arterial embolization, respectively. A radiologist mean hand dose of 19.3 uSv per examination was found, whilst the average eye dose for both radiologist and scrub nurse was 13.4 uSv per examination. The patient dosimetry results revealed a mean thyroid dose of 1.7 mSv and a dose-area product of 48.5 Gy cm 2 for cerebral angiography. Average dose-area product for arterial embolization was 122.2 Gy cm 2 along with a mean patient thyroid dose of 3.3 mSv. More detailed patient dosimetry was also performed using a Rando anthropomorphic phantom loaded with TLDs to measure organ doses and hence estimate effective dose. A typical four vessel angiogram was found to result in a patient effective dose of 3.6 mSv. In the main, occupationally exposed individuals working in radiology departments receive radiation doses which are very low. However, certain small groups of staff who have to stand adjacent to the patient couch during fluoroscopy receive higher doses. The radiation dose to staff performing barium studies are minimized by using dedicated equipment which either has lead curtains suspended from the image intensifier housing or can be operated remotely from behind the protective barrier at the equipment console. Additional radiation protection problems occur in the case of interventional radiology, as fluoroscopy times tend to be longer and the nature of the procedures performed preclude the use of lead protection attached to the image intensifier. Moreover, it is likely that other clinical specialists may also be present in the room during the interventional procedure. A recent review of staff doses in fluoroscopy [1] has indicated that, for high workloads and for some interventional radiology procedures, certain individuals could receive a radiation dose close to the level at which they would need to become a classified radiation worker. It was also apparent that few staff dosimetry studies had been performed
88 citations
TL;DR: Total radiation exposure was reduced in both groups when the angioplasty procedure was combined with the diagnostic angiogram, and efforts to reduce the amount of radiation exposure should remain a priority in interventional catheterization laboratories.
Abstract: Coronary angioplasty of chronic total occlusions is known to have a lower success rate and higher frequency of restenosis than angioplasty of subtotal stenoses, but there are no data describing the additional time, resources, and radiation exposure associated with this procedure. The purpose of this study was to compare these features in 90 consecutive patients who underwent angioplasty of a total occlusion (group 1) to those of 100 consecutive patients who underwent angioplasty of a subtotal stenosis (group 2). Angioplasty was successful in 60% of group 1 and in 94% of group 2 patients. Procedures were longer in group 1 and significantly more guide catheters, angioplasty balloon catheters, and guide wires were required per patient compared to group 2. The volume of contrast media used in each group was similar. Estimates of radiation entry exposure, calculated from fluoroscopy exposure times and using data from phantom studies, were 53 R (roentgen) per patient in group 1 vs. 34 R in group 2. These procedures were performed using pulsed progressive fluoroscopy; radiation exposure would be considerably higher using conventional fluoroscopic systems. Cineangiographic radiation exposures were similar for each group and accounted for an average additional exposure of 14-22 R for each procedure. Total radiation exposure was reduced in both groups when the angioplasty procedure was combined with the diagnostic angiogram. These observations should be considered when dilation of a total occlusion is planned. Efforts to reduce the amount of radiation exposure should remain a priority in interventional catheterization laboratories.
72 citations