Advances in image reconstruction are necessary to decrease radiation exposure from coronary CT angiography (CCTA) further, but iterative reconstruction has been shown to degrade image quality at high ...levels. Deep-learning image reconstruction (DLIR) offers unique opportunities to overcome these limitations. The present study compared the impact of DLIR and adaptive statistical iterative reconstruction-Veo (ASiR-V) on quantitative and qualitative image parameters and the diagnostic accuracy of CCTA using invasive coronary angiography (ICA) as the standard of reference.
This retrospective study includes 43 patients who underwent clinically indicated CCTA and ICA. Datasets were reconstructed with ASiR-V 70% (using standard SD and high-definition HD kernels) and with DLIR at different levels (i.e., medium M and high H). Image noise, image quality, and coronary luminal narrowing were evaluated by three blinded readers. Diagnostic accuracy was compared against ICA.
Noise did not significantly differ between ASiR-V SD and DLIR-M (37 vs. 37 HU, p = 1.000), but was significantly lower in DLIR-H (30 HU, p < 0.001) and higher in ASiR-V HD (53 HU, p < 0.001). Image quality was higher for DLIR-M and DLIR-H (3.4–3.8 and 4.2–4.6) compared to ASiR-V SD and HD (2.1–2.7 and 1.8–2.2; p < 0.001), with DLIR-H yielding the highest image quality. Consistently across readers, no significant differences in sensitivity (88% vs. 92%; p = 0.453), specificity (73% vs. 73%; p = 0.583) and diagnostic accuracy (80% vs. 82%; p = 0.366) were found between ASiR-V HD and DLIR-H.
DLIR significantly reduces noise in CCTA compared to ASiR-V, while yielding superior image quality at equal diagnostic accuracy.
The present study evaluated the impact of deep-learning image reconstruction (DLIR) on noise, image quality, and diagnostic accuracy. In 43 patients who underwent clinically indicated coronary CT angiography and invasive coronary angiography, image quality was improved by up to 62% at similar noise levels. In addition, DLIR-H yielded the highest noise reduction (up to 43%) and best image quality (improvement of up to 138%). More importantly, sensitivity (92% vs. 88%), specificity (73% vs. 73%) and diagnostic accuracy (82% vs. 80%) of DLIR were at least non-inferior to ASiR-V.
Objectives
Different computed tomography (CT) scanners, variations in acquisition protocols, and technical parameters employed for image reconstruction may introduce bias in the analysis of ...pericoronary adipose tissue (PCAT) attenuation derived from coronary computed tomography angiography (CCTA). Therefore, the aim of this study was to establish the effect of tube voltage, measured as kilovoltage peak (kVp), and iterative reconstruction on PCAT mean attenuation (PCAT
MA
).
Methods
Twelve healthy ex vivo porcine hearts were injected with iodine-enriched agar-agar to allow for ex vivo CCTA imaging on a 256-slice CT and a dual-source CT system. Images were acquired at tube voltages of 80, 100, 120, and 140 kVp and reconstructed by using both filtered back projection and iterative reconstruction algorithms. PCAT
MA
was measured semi-automatically on CCTA images in the proximal segment of coronary arteries.
Results
The tube voltage showed a significant effect on PCAT
MA
measurements on both the 256-slice CT scanner (
p
< 0.001) and the dual-source CT system (
p
= 0.013), resulting in higher attenuation values with increasing tube voltage. Similarly, the use of iterative reconstructions was associated with a significant increase of PCAT
MA
(256-slice CT:
p
< 0.001 and dual-source CT:
p
= 0.014). Averaged conversion factors to correct PCAT
MA
measurements for tube voltage other than 120 kVp were 1.267, 1.080 and 0.947 for 80, 100, and 140 kVp, respectively.
Conclusion
PCAT
MA
values are significantly affected by acquisition and reconstruction parameters. The same tube voltage and reconstruction type are recommended when PCAT attenuation is used in multicenter and longitudinal studies.
Key Points
• The tube voltage used for CCTA acquisition affects pericoronary adipose tissue attenuation, resulting in higher attenuation values of fat with increasing tube voltage.
• Conversion factors for pericoronary adipose tissue attenuation values could be used to adjust for differences in attenuation between scans performed at different tube voltages.
• In longitudinal CCTA studies employing pericoronary adipose tissue attenuation as imaging endpoint, it is recommended to maintain tube voltage and image reconstruction type constant across serial scans.
Abstract Anomalous coronary arteries (ACA) represent a congenital disorder with an anomalous location of the coronary ostium and/or vascular course. Although most individuals with ACA are ...asymptomatic and remain undiagnosed, some ACA variants are clinically significant leading to symptoms and even adverse cardiac events. Currently, disease prevalence, pathophysiological mechanisms, risks of sudden cardiac death, and the optimal assessment and treatment strategies among subtypes of ACA remain largely unknown. Consequently, there is a lack of guidelines regarding imaging, sport restriction, and treatment options in individuals with ACA at all ages. Cardiac imaging techniques may play a pivotal role in the assessment of individuals with ACA and may offer guidance toward an optimal treatment strategy. This state-of-the-art review highlights current challenges and future perspectives with a special focus on the role of noninvasive multimodality imaging in patients with ACA.
The use of myocardial perfusion imaging has seen a tremendous growth during the last decade and has become the most commonly used non-invasive imaging tool for risk stratification in patients with ...suspected and known coronary artery disease. Adherence to radiation safety best practices varied significantly between laboratories but the possibility to use the new cameras in nuclear cardiology can reduce dramatically the radiation dose without losing accuracy. Moreover, the physical characteristics of ultrafast technology could be able to open new doors for the evaluation of old parameters, changing the impact of nuclear cardiology in the diagnostic strategies.
Purpose Left ventricular non-compaction (LVNC) is characterized by a 2-layered myocardium composed of a noncompacted (NC) and a compacted (C) layer. The echocardiographic NC:C ratio is difficult to ...assess in many patients. The aim of the study was to assess the value of cardiac computed tomography (CCT) for the diagnosis of LVNC. Methods In this prospective controlled study, segmental analysis of transthoracic echocardiography (TTE) and prospective ECG-triggered CCT was performed in 17 patients with LVNC and 19 healthy controls. In TTE maximal NC and C thickness was measured at enddiastole and endsystole in the segment with most prominent trabeculation in short axis views. In CCT, maximal segmental NC and C thickness was measured during diastole, and NC:C ratio was determined. Spearman’s correlation coefficient and receiver operating characteristic curves were calculated. Results The median IQR radiation dose was 1.31.2–1.5mSv. The CCT thickness of the C layer was significantly lower in patients with LVNC as compared to controls in the inferolateral, midventricular, lateral-, inferior-, and septal-apical segments. The CCT NC:C ratio differed significantly between LVNC and controls in the inferior-midventricular and all the apical segments. NC:C ratio correlated significantly between TTE and CCT at enddiastole (σ = 0.8) and endsystole (σ = 0.9). Using a CCT NC:C ratio ≥1.8, all LVNC patients could be identified. Conclusion LVNC can be diagnosed with ECG-triggered low-dose CCT and discriminated from normal individuals using a NC:C ratio of ≥1.8 in diastole. There is a very good correlation of NC:C ratio in TTE and CCT.
Aims
In adults with congenital heart disease and systemic right ventricles, progressive right ventricular systolic dysfunction is common and is associated with adverse outcomes. Our aim was to assess ...the impact of the phosphodiesterase‐5‐inhibitor tadalafil on right ventricular systolic function.
Methods and results
This was a double‐blind, randomized, placebo‐controlled, multicentre superiority trial (NCT03049540) involving 100 adults with systemic right ventricles (33 women, mean age: 40.7 ± 10.7 years), comparing tadalafil 20 mg once daily versus placebo (1:1 ratio). The primary endpoint was the change in right ventricular end‐systolic volume after 3 years of therapy. Secondary endpoints were changes in right ventricular ejection fraction, exercise capacity and N‐terminal pro‐B‐type natriuretic peptide concentration. Primary endpoint assessment by intention to treat analysis at 3 years of follow‐up was possible in 83 patients (42 patients in the tadalafil group and 41 patients in the placebo group). No significant changes over time in right ventricular end‐systolic volumes were observed in the tadalafil and the placebo group, and no significant differences between treatment groups (3.4 ml, 95% confidence interval −4.3 to 11.0, p = 0.39). No significant changes over time were observed for the pre‐specified secondary endpoints for the entire study population, without differences between the tadalafil and the placebo group.
Conclusions
In this trial in adults with systemic right ventricles, right ventricular systolic function, exercise capacity and neuro‐hormonal activation remained stable over a 3‐year follow‐up period. No significant treatment effect of tadalafil was observed. Further research is needed to find effective treatment for improvement of ventricular function in adults with systemic right ventricles.
Promising effects of phosphodiesterase‐5 inhibition on function of hypertrophied right ventricles in experimental and animal models did not translate into a clinical benefit in this randomized, placebo‐controlled trial in adults with congenital heart disease and systemic right ventricles. Tadalafil had no impact on right ventricular function, exercise capacity or neuro‐hormonal activation. Further prospective studies on the effectiveness of novel treatment options for these patients are urgently needed. RV, right ventricle; RVEF, right ventricular ejection fraction; VO2, oxygen uptake.
Abstract
Aims
HIV-positive persons have increased cardiovascular event rates but data on the prevalence of subclinical atherosclerosis compared with HIV-negative persons are not uniform. We assessed ...subclinical atherosclerosis utilizing coronary artery calcium (CAC) scoring and coronary computed tomography angiography (CCTA) in 428 HIV-positive participants of the Swiss HIV Cohort Study and 276 HIV-negative controls concurrently referred for clinically indicated CCTA.
Methods and results
We assessed the association of HIV infection, cardiovascular risk profile, and HIV-related factors with subclinical atherosclerosis in univariable and multivariable analyses. HIV-positive participants (median duration of HIV infection, 15 years) were younger than HIV-negative participants (median age 52 vs. 56 years; P < 0.01) but had similar median 10-year Framingham risk scores (9.0% vs. 9.7%; P = 0.40). The prevalence of CAC score >0 (53% vs. 56.2%; P = 0.42) and median CAC scores (47 vs. 47; P = 0.80) were similar, as was the prevalence of any, non-calcified/mixed, and high-risk plaque. In multivariable adjusted analysis, HIV-positive participants had a lower prevalence of calcified plaque than HIV-negative participants 36.9% vs. 48.6%, P < 0.01; adjusted odds ratio (aOR) 0.57; 95% confidence interval (CI) 0.40–0.82; P < 0.01, lower coronary segment severity score (aOR 0.72; 95% CI 0.53–0.99; P = 0.04), and lower segment involvement score (aOR 0.71, 95% CI 0.52–0.97; P = 0.03). Advanced immunosuppression was associated with non-calcified/mixed plaque (aOR 1.97; 95% CI 1.09–3.56; P = 0.02).
Conclusion
HIV-positive persons in Switzerland had a similar degree of non-calcified/mixed plaque and high-risk plaque, and may have less calcified coronary plaque, and lower coronary atherosclerosis involvement and severity scores than HIV-negative persons with similar Framingham risk scores.
As a professional group, physicians are at increased risk of burnout and job stress, both of which are associated with an increased risk of coronary heart disease that is at least as high as that of ...other professionals. This study aimed to examine the association of burnout and job stress with coronary microvascular function, a predictor of major adverse cardiovascular events.
Thirty male physicians with clinical burnout and 30 controls without burnout were included. Burnout was assessed with the Maslach Burnout Inventory and job stress with the effort-reward imbalance and overcommitment questionnaire. All participants underwent myocardial perfusion positron emission tomography to quantify endothelium-dependent (cold pressor test) and endothelium-independent (adenosine challenge) coronary microvascular function. Burnout and job stress were regressed on coronary flow reserve (primary outcome) and two additional measures of coronary microvascular function in the same model while adjusting for age and body mass index.
Burnout and job stress were significantly and independently associated with endothelium-dependent microvascular function. Burnout was positively associated with coronary flow reserve, myocardial blood flow response, and hyperemic myocardial blood flow (r partial = 0.28 to 0.35; p-value = 0.008 to 0.035). Effort-reward ratio (r partial = - 0.32 to - 0.38; p-value = 0.004 to 0.015) and overcommitment (r partial = - 0.30 to - 0.37; p-value = 0.005 to 0.022) showed inverse associations with these measures.
In male physicians, burnout and high job stress showed opposite associations with coronary microvascular endothelial function. Longitudinal studies are needed to show potential clinical implications and temporal relationships between work-related variables and coronary microvascular function. Future studies should include burnout and job stress for a more nuanced understanding of their potential role in cardiovascular health.
Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of ...progress have been made, improving MPI procedures. In this paper, the major changes from the updated 2015 procedural guidelines are highlighted, focusing on the important changes related to new instrumentation with improved image information and the possibility to reduce radiation exposure, which is further discussed in relation to the recent developments of new International Commission on Radiological Protection (ICRP) models. Introduction of the selective coronary vasodilator regadenoson and the use of coronary CT-contrast agents for hybrid imaging with SPECT/CT angiography are other important areas for nuclear cardiology that were not included in the previous guidelines. A large number of minor changes have been described in more detail in the fully revised version available at the EANM home page:
http://eanm.org/publications/guidelines/2015_07_EANM_FINAL_myocardial_perfusion_guideline.pdf
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