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168 result(s) for "Cardiac Imaging Techniques - standards"
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Nuclear cardiology practice and associated radiation doses in Europe: results of the IAEA Nuclear Cardiology Protocols Study (INCAPS) for the 27 European countries
Purpose Nuclear cardiology is widely used to diagnose coronary artery disease and to guide patient management, but data on current practices, radiation dose-related best practices, and radiation doses are scarce. To address these issues, the IAEA conducted a worldwide study of nuclear cardiology practice. We present the European subanalysis. Methods In March 2013, the IAEA invited laboratories across the world to document all SPECT and PET studies performed in one week. The data included age, gender, weight, radiopharmaceuticals, injected activities, camera type, positioning, hardware and software. Radiation effective dose was calculated for each patient. A quality score was defined for each laboratory as the number followed of eight predefined best practices with a bearing on radiation exposure (range of quality score 0 – 8). The participating European countries were assigned to regions (North, East, South, and West). Comparisons were performed between the four European regions and between Europe and the rest-of-the-world (RoW). Results Data on 2,381 European patients undergoing nuclear cardiology procedures in 102 laboratories in 27 countries were collected. A cardiac SPECT study was performed in 97.9 % of the patients, and a PET study in 2.1 %. The average effective dose of SPECT was 8.0 ± 3.4 mSv (RoW 11.4 ± 4.3 mSv; P  < 0.001) and of PET was 2.6 ± 1.5 mSv (RoW 3.8 ± 2.5 mSv; P  < 0.001). The mean effective doses of SPECT and PET differed between European regions ( P  < 0.001 and P  = 0.002, respectively). The mean quality score was 6.2 ± 1.2, which was higher than the RoW score (5.0 ± 1.1; P  < 0.001). Adherence to best practices did not differ significantly among the European regions (range 6 to 6.4; P  = 0.73). Of the best practices, stress-only imaging and weight-adjusted dosing were the least commonly used. Conclusion In Europe, the mean effective dose from nuclear cardiology is lower and the average quality score is higher than in the RoW. There is regional variation in effective dose in relation to the best practice quality score. A possible reason for the differences between Europe and the RoW could be the safety culture fostered by actions under the Euratom directives and the implementation of diagnostic reference levels. Stress-only imaging and weight-adjusted activity might be targets for optimization of European nuclear cardiology practice.
Quantitative inversion time prescription for myocardial late gadolinium enhancement using T1-mapping-based synthetic inversion recovery imaging: reducing subjectivity in the estimation of inversion time
To develop a quantitative T1-mapping-based synthetic inversion recovery (IRsynth) approach to calculate the optimal inversion time (TI0) for late gadolinium enhancement (LGE) imaging. Prospectively enrolled patients (n = 130, 58 ± 16 years) underwent cardiac MRI on a 1.5T system including Look-Locker TI-scout (LL), modified LL IR (MOLLI)-based T1-mapping, and LGE acquisitions. Patients were randomized into two groups: LL group (TI-scout followed T1-mapping) or MOLLI group (T1-mapping followed TI-scout). In both groups, the second acquisition was used to determine the TI0 for LGE. IRsynth images were generated from T1-maps between TI = 200–400 ms in 5 ms increments. Image quality was rated on a 3-point scale and the remote/background signal intensity ratio (SIR) was calculated. In the LL group (n = 53), the TI-scout-based TI0 was significantly shorter compared to IRsynth [230 ms (219–242) vs. 280 ms (263–297), P < 0.0001]. The TI0 used for LGE was set 30–40 ms longer [261 ms (247–276), P < 0.0001] than the TI-scout-based TI0, resulting in a TI0 ~ 20 ms shorter than what was obtained by IRsynth (P = 0.0156). In the MOLLI group (n = 63), IRsynth-based TI0 was significantly longer than the TI-scout-based TI0 [298 ms (262–334) vs. 242 ms (217–267), P = 0.0313]. The quality of myocardial nulling was rated higher [2.4 (2.2–2.5) vs. 2.0 (1.8–2.1), P = 0.0042] and the remote/background SIR was found to be more optimal (1.6 [1.1–2.1] vs. 2.6 [1.8–3.3], P = 0.0256) in the MOLLI group. T1-based IRsynth selects TI0 for LGE more accurately than conventional TI-scout imaging. IRsynth improves TI0 selection by providing excellent visualization of the representative image contrast for LGE images, reducing operator dependence in LGE acquisition.
Role of multimodality cardiac imaging in the management of patients with hypertrophic cardiomyopathy: an expert consensus of the European Association of Cardiovascular Imaging Endorsed by the Saudi Heart Association
Taking into account the complexity and limitations of clinical assessment in hypertrophic cardiomyopathy (HCM), imaging techniques play an essential role in the evaluation of patients with this disease. Thus, in HCM patients, imaging provides solutions for most clinical needs, from diagnosis to prognosis and risk stratification, from anatomical and functional assessment to ischaemia detection, from metabolic evaluation to monitoring of treatment modalities, from staging and clinical profiles to follow-up, and from family screening and preclinical diagnosis to differential diagnosis. Accordingly, a multimodality imaging (MMI) approach (including echocardiography, cardiac magnetic resonance, cardiac computed tomography, and cardiac nuclear imaging) is encouraged in the assessment of these patients. The choice of which technique to use should be based on a broad perspective and expert knowledge of what each technique has to offer, including its specific advantages and disadvantages. Experts in different imaging techniques should collaborate and the different methods should be seen as complementary, not as competitors. Each test must be selected in an integrated and rational way in order to provide clear answers to specific clinical questions and problems, trying to avoid redundant and duplicated information, taking into account its availability, benefits, risks, and cost.
Patient preparation for cardiac fluorine-18 fluorodeoxyglucose positron emission tomography imaging of inflammation
Although the number of clinical applications for fluorine-18 fluorodeoxyglucose (18F-FDG) cardiac positron emission tomography (PET) has continued to grow, there remains a lack of consensus regarding the ideal method of suppressing normal myocardial glucose utilization for image optimization. This review describes various patient preparation protocols that have been used as well as the success rates achieved in different studies. Collectively, the available literature supports using a high-fat, no-carbohydrate diet for at least two meals with a fast of 4-12 hours prior to 18F-FDG PET imaging and suggests that isolated fasting for less than 12 hours and supplementation with food or drink just prior to imaging should be avoided. Each institution should adopt a protocol and continuously monitor its effectiveness with a goal to achieve adequate myocardial suppression in greater than 80% of patients.
Relevance of cardiac imaging in the evolving landscape of infective endocarditis management
Infective endocarditis (IE) is an increasingly recognized condition with high morbidity. Patients with atypical symptoms, culture-negative infections, and prosthetic cardiac devices and implants represent challenging populations to evaluate and manage. Recent major society guidelines have recommended the appropriate incorporation of multimodality imaging in the evaluation of these more complex IE cases. This article draws on the available literature regarding the different cardiac imaging modalities and discusses the role of multimodality imaging in IE.
2017 Multimodality Appropriate Use Criteria for Noninvasive Cardiac Imaging: Expert Consensus of the Asian Society of Cardiovascular Imaging
In 2010, the Asian Society of Cardiovascular Imaging (ASCI) provided recommendations for cardiac CT and MRI, and this document reflects an update of the 2010 ASCI appropriate use criteria (AUC). In 2016, the ASCI formed a new working group for revision of AUC for noninvasive cardiac imaging. A major change that we made in this document is the rating of various noninvasive tests (exercise electrocardiogram, echocardiography, positron emission tomography, single-photon emission computed tomography, radionuclide imaging, cardiac magnetic resonance, and cardiac computed tomography/angiography), compared side by side for their applications in various clinical scenarios. Ninety-five clinical scenarios were developed from eight selected pre-existing guidelines and classified into four sections as follows: 1) detection of coronary artery disease, symptomatic or asymptomatic; 2) cardiac evaluation in various clinical scenarios; 3) use of imaging modality according to prior testing; and 4) evaluation of cardiac structure and function. The clinical scenarios were scored by a separate rating committee on a scale of 1-9 to designate appropriate use, uncertain use, or inappropriate use according to a modified Delphi method. Overall, the AUC ratings for CT were higher than those of previous guidelines. These new AUC provide guidance for clinicians choosing among available testing modalities for various cardiac diseases and are also unique, given that most previous AUC for noninvasive imaging include only one imaging technique. As cardiac imaging is multimodal in nature, we believe that these AUC will be more useful for clinical decision making.
Three-dimensional printing in cardiology: Current applications and future challenges
Three-dimensional (3D) printing has attracted a huge interest in recent years. Broadly speaking, it refers to the technology which converts a predesigned virtual model to a touchable object. In clinical medicine, it usually converts a series of two-dimensional medical images acquired through computed tomography, magnetic resonance imaging or 3D echocardiography into a physical model. Medical 3D printing consists of three main steps: image acquisition, virtual reconstruction and 3D manufacturing. It is a promising tool for preoperative evaluation, medical device design, hemodynamic simulation and medical education, it is also likely to reduce operative risk and increase operative success. However, the most relevant studies are case reports or series which are underpowered in testing its actual effect on patient outcomes. The decision of making a 3D cardiac model may seem arbitrary since it is mostly based on a cardiologist's perceived difficulty in performing an interventional procedure. A uniform consensus is urgently necessary to standardize the key steps of 3D printing from imaging acquisition to final production. In the future, more clinical trials of rigorous design are possible to further validate the effect of 3D printing on the treatment of cardiovascular diseases. (Cardiol J 2017; 24, 4: 436-444).
The Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Left Ventricular Function: Current Evidence and Future Directions
Abstract Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a unique class of oral anti-hyperglycaemic medications that act to reduce glucose reabsorption in the renal proximal tubules, thereby enhancing urinary glucose excretion. Large randomized placebo-controlled trials in people with diabetes at high cardiovascular risk have demonstrated that SGLT2 inhibitors reduce heart failure hospitalization within months of commencing therapy. These findings are of considerable interest, as diabetes is associated with an increased risk of both heart failure with reduced ejection fraction and heart failure with preserved ejection fraction. In addition, left ventricular (LV) hypertrophy and impaired diastolic function is thought to be more prevalent in people with diabetes. Although many hypotheses have been proposed, the underlying mechanisms through which SGLT2 inhibitors reduce the risk of heart failure in people with diabetes are not fully understood. Given the rapid reduction in heart failure hospitalization, it is conceivable that the benefits of SGLT2 inhibitors are due to favourable haemodynamic and metabolic effects on LV function. Several clinical studies have been conducted to investigate the effect of SGLT2 inhibitors on LV structure and function and have found that LV mass index and diastolic function improve following SGLT2 inhibitor therapy in people with type 2 diabetes. If these findings are confirmed in future studies utilizing novel cardiac imaging modalities and large randomized controlled trials, then this will bring new hope for the prevention and management of heart failure with preserved ejection fraction, for which no current treatments have been shown to reduce mortality. At the present time, SGLT2 inhibitors are indicated for the treatment of type 2 diabetes; however, the results of ongoing trials in participants with heart failure but without diabetes are eagerly awaited. The purpose of this review is to summarize current knowledge regarding the effects of SGLT2 inhibitors on LV function, particularly the findings from clinical studies, proposed biological mechanisms, and future directions.
Myocardial T1 and extracellular volume fraction mapping at 3 tesla
Background To compare 11 heartbeat (HB) and 17 HB modified lock locker inversion recovery (MOLLI) pulse sequence at 3T and to establish preliminary reference values for myocardial T1 and the extracellular volume fraction (ECV). Methods Both phantoms and normal volunteers were scanned at 3T using 11 HB and 17 HB MOLLI sequence with the following parameters: spatial resolution = 1.75 × 1.75 × 10 mm on a 256 × 180 matrix, TI initial = 110 ms, TI increment = 80 ms, flip angle = 35°, TR/TE = 1.9/1.0 ms. All volunteers were administered Gadolinium-DTPA (Magnevist, 0.15 mmol/kg), and multiple post-contrast MOLLI scans were performed at the same pre-contrast position from 3.5-23.5 minutes after a bolus contrast injection. Late gadolinium enhancement (LGE) images were also acquired 12-30 minutes after the gadolinium bolus. Results T1 values of 11 HB and 17 HB MOLLI displayed good agreement in both phantom and volunteers. The average pre-contrast myocardial and blood T1 was 1315 ± 39 ms and 2020 ± 129 ms, respectively. ECV was stable between 8.5 to 23.5 minutes post contrast with an average of 26.7 ± 1.0%. Conclusion The 11 HB MOLLI is a faster method for high-resolution myocardial T1 mapping at 3T. ECV fractions are stable over a wide time range after contrast administration.
Physicians' professional identities: a roadmap to understanding “value” in cardiovascular imaging
Quality improvement efforts in cardiovascular imaging have been challenged by limited adoption of initiatives and policies. In order to better understand this limitation and inform future efforts, the range clinical values related to cardiovascular imaging at a large academic hospital was characterized. 15 Northwestern Medicine physicians from internal medicine, cardiology, emergency medicine, cardiac/vascular surgery, and radiology were interviewed about their use of cardiovascular imaging and imaging guidelines. Interview transcripts were systemically analyzed according to constructivist grounded theory and combined with 56 previous interviews with interventional radiologists, interventional cardiologists, gynecologists, and vascular surgeons to develop a model describing specialty-specific values. This model was applied to the 15 pilot interviews focused on cardiovascular imaging, highlighting specialty specific differences in values and practice patterns. Transcripts were also reviewed independently by a cardiologist and 2 radiologists followed by a group discussion to assess reproducibility and achieve a consensus regarding the results. Differences in perceived value of cardiovascular imaging and use of guidelines among physicians were well explained by three value-associated identity categories (managers, diagnosticians, and fixers) that were further differentiated along three axes (broad v. focused-thinkers, complex v. definitive-answer-seekers, and public visibility). Quality improvement in cardiovascular imaging may be limited by a lack of understanding and incorporation of the complexity of medical culture into ongoing initiatives. Both individually and during policy development, it is important to first understand the complexity of stakeholders' diverse perceptions of “value,” “quality,” and “appropriateness.”