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Journal ArticleDOI

Evaluation of coronary angiographic projections to balance the clinical yield with the radiation risk

18 Apr 2012-British Journal of Radiology (British Institute of Radiology)-Vol. 85, Iss: 1017

AbstractObjective: Radiation safety principles dictate that imaging procedures should minimise the radiation risks involved, without compromising diagnostic performance. This study aims to define a core set of views that maximises clinical information yield for minimum radiation risk. Angiographers would supplement these views as clinically indicated. Methods: An algorithm was developed to combine published data detailing the quality of information derived for the major coronary artery segments through the use of a common set of views in angiography with data relating to the dose–area product and scatter radiation associated with these views. Results: The optimum view set for the left coronary system comprised four views: left anterior oblique (LAO) with cranial (Cr) tilt, shallow right anterior oblique (AP-RAO) with caudal (Ca) tilt, RAO with Ca tilt and AP-RAO with Cr tilt. For the right coronary system three views were identified: LAO with Cr tilt, RAO and AP-RAO with Cr tilt. An alternative left coronary view set including a left lateral achieved minimally superior efficiency (,5%), but with an ,8% higher radiation dose to the patient and 40% higher cardiologist dose. Conclusion: This algorithm identifies a core set of angiographic views that optimises the information yield and minimises radiation risk. This basic data set would be supplemented by additional clinically determined views selected by the angiographer for each case. The decision to use additional views for diagnostic angiography and interventions would be assisted by referencing a table of relative radiation doses for the views being considered.

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Citations
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Journal ArticleDOI
TL;DR: The purpose of this study was to quantify the reduction in patient radiation dose during coronary angiography by a new X‐ray technology, and to assess its impact on diagnostic image quality.
Abstract: Objectives The purpose of this study was to quantify the reduction in patient radiation dose during coronary angiography (CA) by a new X-ray technology, and to assess its impact on diagnostic image quality. Background Recently, a novel X-ray imaging technology has become available for interventional cardiology, using advanced image processing and an optimized acquisition chain for radiation dose reduction. Methods 70 adult patients were randomly assigned to a reference X-ray system or the novel X-ray system. Patient demographics were registered and exposure parameters were recorded for each radiation event. Clinical image quality was assessed for both patient groups. Results With the same angiographic technique and a comparable patient population, the new imaging technology was associated with a 75% reduction in total kerma-area product (KAP) value (decrease from 47 Gycm2 to 12 Gycm2, P < 0.001). Clinical image quality showed an equivalent detail and contrast for both imaging systems. On the other hand, the subjective appreciation of noise was more apparent in images of the new image processing system, acquired at lower doses, compared to the reference system. However, the higher noise content did not affect the overall image quality score, which was adequate for diagnosis in both systems. Conclusions For the first time, we present a new X-ray imaging technology, combining advanced noise reduction algorithms and an optimized acquisition chain, which reduces patient radiation dose in CA drastically (75%), while maintaining diagnostic image quality. Use of this technology may further improve the radiation safety of cardiac angiography and interventions. © 2015 Wiley Periodicals, Inc.

35 citations


Journal ArticleDOI
TL;DR: An acousto-optical optical fiber sensor for tracking catheter position during interventional magnetic resonance imaging (MRI) to overcome RF induced heating of active markers and it has been successfully used to detect the position of a tacking coil in phantom in an imaging experiment.
Abstract: Objective: The objective of this paper is to introduce an acousto-optic optical fiber sensor for tracking catheter position during interventional magnetic resonance imaging (MRI) to overcome RF induced heating of active markers. Methods: The sensor uses a miniature coil coupled to a piezoelectric transducer, which is in turn mechanically connected to an optical fiber. The piezoelectric transducer converts the RF signal to acoustic waves in the optical fiber over a region including a fiber Bragg grating (FBG). The elastic waves in the fiber modulates the FBG geometry and hence the reflected light in the optical fiber. Since the coil is much smaller than the RF wavelength and the signal is transmitted on the dielectric optical fiber, the sensor effectively reduces RF induced heating risk. Proof of concept prototypes of the sensor are implemented using commercially available piezoelectric transducers and optical fibers with FBGs. The prototypes are characterized in a 1.5 T MRI system in comparison with an active tracking marker. Results: Acousto-optical sensor shows linear response with flip angle and it can be used to detect signals from multiple coils for potential orientation detection. It has been successfully used to detect the position of a tacking coil in phantom in an imaging experiment. Conclusion: Acousto-optical sensing is demonstrated for tracking catheters during interventional MRI. Real-time operation of the sensor requires sensitivity improvements like using a narrow band FBG. Significance: Acousto-optics provides a compact solution to sense RF signals in MRI with dielectric transmission lines.

7 citations


Journal ArticleDOI
TL;DR: It is suggested that a process relying on elements of comparative effectiveness and the use of standardized BRC may ensure consistent examination of differences among alternatives by way of making explicit implicit trade-offs that otherwise enter the decision-making space and detract from consistency and transparency.
Abstract: Rationale and Objectives Diagnostic imaging has many effects and there is no common definition of value in diagnostic radiology. As benefit-risk trade-offs are rarely made explicit, it is not clear which framework is used in clinical guideline development. We describe initial steps toward the creation of a benefit-risk framework for diagnostic radiology. Materials and Methods We performed a literature search and an online survey of physicians to identify and collect benefit-risk criteria (BRC) relevant to diagnostic imaging tests. We operationalized a process for selection of BRC with the use of four clinical use case scenarios that vary by diagnostic alternatives and clinical indication. Respondent BRC selections were compared across clinical scenarios and between radiologists and nonradiologists. Results Thirty-six BRC were identified and organized into three domains: (1) those that account for differences attributable only to the test or device ( n = 17); (2) those that account for clinical management and provider experiences ( n = 12); and (3) those that capture patient experience ( n = 7). Forty-eight survey participants selected 22 criteria from the initial list in the survey (9–11 per case). Engaging ordering physicians increased the number of criteria selected in each of the four clinical scenarios presented. We developed a process for standardizing selection of BRC in guideline development. Conclusion These results suggest that a process relying on elements of comparative effectiveness and the use of standardized BRC may ensure consistent examination of differences among alternatives by way of making explicit implicit trade-offs that otherwise enter the decision-making space and detract from consistency and transparency. These findings also highlight the need for multidisciplinary teams that include input from ordering physicians.

6 citations


Journal ArticleDOI
TL;DR: Specific angiographic projections expose patients to significantly higher radiation and they should be avoided and replaced by less irradiating projections whenever possible.
Abstract: Introduction: We aimed to determine angiography projections with lower Dose Area Product (DAP) rate by measuring the mean DAP and fluoroscopy times in coronary angiography (CAG) and percutaneous coronary intervention (PCI) and calculating DAP rate in different projections. Methods: DAP and fluoroscopy times were measured in all employed projections in real-time in 75 patients who underwent CAG or PCI by a single cardiologist in Madani Cardiovascular University Hospital (45 in CAG group and 30 in PCI group). DAP rate was calculated in both groups and in all projections. The projections with highest and lowest DAP rate were determined. Results: Mean DAP was 436.73±315.85 dGy×cm2 in CAG group and 643.26±359.58 dGy×cm2 in PCI group. The projection 40° LAO/0° had the highest DAP rate in CAG group (28.98 dGy×cm2/ sec) and it was highest in 20° RAO/30° CR in PCI group (29.83 dGy×cm2/sec). The latter projection was also the most employed projection in PCI group. Conclusion: The amount of radiation dose in this study is in consistent with the previous reports. Specific angiographic projections expose patients to significantly higher radiation and they should be avoided and replaced by less irradiating projections whenever possible.

6 citations


01 Jan 2013
TL;DR: Coronary angiography is a common interventional diagnostic procedure that is used to diagnose cardiovascular conditions such as heart attack, heart failure and angina, Breast dose in CA is conventionally believed to be low and breast cancers arising.
Abstract: Coronary angiography (CA) is a common interventional diagnostic procedure that is used to diagnose cardiovascular conditions such as heart attack, heart failure and angina, Breast dose in CA is conventionally believed to be low and breast cancers arising

4 citations


References
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01 Jul 1959
TL;DR: Recommendations are presented which represent concepts and practices evolved from recent discussions at formal and informal meetings of the Commission and its Committees.
Abstract: The International Commission on Radiological Protection has been functioning since 1928 when it was established, under the name of International X- ray and Radium Protection Commission, by the Second International Congress of Radiology held in Stockholm, Sweden. It assumed the present name and organizational form in 1950 in order to cover more effectively the rapidly expanding field of radiation protection. Recommendations are presented which represent concepts and practices evolved from recent discussions at formal and informal meetings of the Commission and its Committees. (auth)

6,019 citations


Journal ArticleDOI
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.

1,586 citations


Journal ArticleDOI
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 …

766 citations


Journal ArticleDOI

304 citations


Journal ArticleDOI
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.

167 citations