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Left ventricular ejection fraction (LVEF) and end-systolic volume (ESV) remain the main imaging biomarkers for post-acute myocardial infarction (AMI) risk stratification. However, they are limited to global systolic function and fail to capture functional and anatomical regional abnormalities, hindering their performance in risk stratification. This study aimed to identify novel 3-dimensional (3D) imaging end-systolic (ES) shape and contraction descriptors toward risk-related features and superior prognosis in AMI. A multicenter cohort of AMI survivors (n = 1,021; median age 63 years; 74.5% male) who underwent cardiac magnetic resonance (CMR) at a median of 3 days after infarction were considered for this study. The clinical endpoint was the 12-month rate of major adverse cardiac events (MACE; n = 73), consisting of all-cause death, reinfarction, and new congestive heart failure. A fully automated pipeline was developed to segment CMR images, build 3D statistical models of shape and contraction in AMI, and find the 3D patterns related to MACE occurrence. The novel ES shape markers proved to be superior to ESV (median cross-validated area under the receiver-operating characteristic curve 0.681 [IQR: 0.679-0.684] vs 0.600 [IQR: 0.598-0.602]; P < 0.001); and 3D contraction to LVEF (0.716 [IQR: 0.714-0.718] vs 0.681 [IQR: 0.679-0.684]; P < 0.001) in MACE occurrence prediction. They also contributed to a significant improvement in a multivariable setting including CMR markers, cardiovascular risk factors, and basic patient characteristics (0.747 [IQR: 0.745-0.749]; P < 0.001). Based on these novel 3D descriptors, 3 impairments caused by AMI were identified: global, anterior, and basal, the latter being the most complementary signature to already known predictors. The quantification of 3D differences in ES shape and contraction, enabled by a fully automated pipeline, improves post-AMI risk prediction and identifies shape and contraction patterns related to MACE occurrence. [Display omitted] [ABSTRACT FROM AUTHOR]

Ventricular interdependence may account for altered ventricular mechanics in congenital heart disease. The present study aimed to identify differences in load-dependent right ventricular (RV)–left ventricular (LV) interactions in porcine models of pulmonary stenosis (PS) and pulmonary insufficiency (PI) by invasive admittance-derived hemodynamics in conjunction with noninvasive cardiovascular magnetic resonance (CMR). Seventeen pigs were used in the study (7 with PS, 7 with PI, and 3 controls). Progressive PS was created by tightening a Teflon tape around the pulmonary artery, and PI was created by excising 2 leaflets of the pulmonary valve. Admittance catheterization data were obtained for the RV and LV at 10 to 12 weeks after model creation, with the animal ventilated under temporary diaphragm paralysis. CMR was performed in all animals immediately prior to pressure–volume catheterization. In the PS group, RV contractility was increased, manifested by increased end-systolic elastance (mean difference, 1.29 mm Hg/mL; 95% confidence interval [CI], 0.57-2.00 mm Hg/mL). However, in the PI group, no significant changes were observed in RV systolic function despite significant changes in RV diastolic function. In the PS group, LV end-systolic volume was significantly lower compared with controls (mean difference, 25.1 mL; 95% CI, -40.5 to -90.7 mL), whereas in the PI group, the LV showed diastolic dysfunction, demonstrated by an elevated isovolumic relaxation constant and ventricular stiffness (mean difference, 0.03 mL−1; 95% CI, -0.02 to 0.09 mL−1). The LV exhibits systolic dysfunction and noncompliance with PI. PS is associated with preserved LV systolic function and evidence of some LV diastolic dysfunction. Interventricular interactions influence LV filling and likely account for differential effects of RV pressure and volume overload on LV function. Porcine models of pressure and volume overload. We developed and acquired pressure–volume loops from porcine models of pulmonary stenosis (PS) and pulmonary insufficiency (PI) from both the right and left ventricles. In addition to expected changes in contractility in compliance for each respective model, we observed mild diastolic dysfunction in both models, suggesting that interventricular interactions are important in understanding pathophysiology. [Display omitted] [ABSTRACT FROM AUTHOR]

BACKGROUND: Correction of tetralogy of Fallot (cTOF) often results in pulmonary valve pathology and right ventricular (RV) dysfunction. Reduced exercise capacity in cTOF patients cannot be explained by these findings alone. We aimed to explore why cTOF patients exhibit impaired exercise capacity with the aid of a comprehensive cardiopulmonary exercise testing (CPET) and real-time cardiovascular magnetic resonance exercise testing (CMR-ET) protocol. METHODS: Thirty three cTOF patients and 35 matched healthy controls underwent CPET and CMR-ET in a prospective casecontrol study. Real-time steady-state free precession cine and phase-contrast sequences were obtained during incremental supine in-scanner cycling at 50, 70, and 90 W. RV and left ventricle (LV) volumes and pulmonary blood flow (Qp) were calculated. Differences of CPET and CMR-ET between cTOF versus controls and correlations between CPET and CMR-ET parameters in cTOF were evaluated statistically for all CMR exercise levels using Mann-Whitney U and Spearman rank-order correlation tests. RESULTS: CPET capacity was significantly lower in cTOF than in controls. cTOF patients exhibited not only significantly reduced Qp and RV function but also lower LV function on CMR-ET. Higher CPET values in cTOF correlated with higher Qp (Qp 90 W versus carbon dioxide ventilatory equivalent %: R=-0.519, P<0.05), higher LV-end-diastolic volume indexed to body surface area (LV-end-diastolic volume indexed to body surface area at 50 W versus oxygen uptake in % at maximum exercise on CPET R=0.452, P<0.05), and change in LV ejection fraction (EF; LV-EF at 90 W versus Watt %: r=-0.463, P<0.05). No correlation was found with regard to RV-EF. Significant RV-LV interaction was observed during CMR-ET (RV-EF versus LV-EF at 50 W and 70 W: r=0.66, P<0.02 and r=0.52, P<0.05, respectively). CONCLUSIONS: Impaired exercise capacity in cTOF resulted from a reduction in not only RV, but also LV function. cTOF with good exercise capacity on CPET demonstrated higher LV reserve and pulmonary blood flow during incremental CMR-ET. Apart from RV parameters, CMR-ET-derived LV function could be a valuable tool to stratify cTOF patients for pulmonary valve replacement. [ABSTRACT FROM AUTHOR]

Importance: Internet and computer game addiction represent a growing mental health concern, acknowledged by the World Health Organization.Objective: To determine whether manualized cognitive behavioral therapy (CBT), using short-term treatment for internet and computer game addiction (STICA), is efficient in individuals experiencing internet and computer game addiction.Design, Setting, and Participants: A multicenter randomized clinical trial was conducted in 4 outpatient clinics in Germany and Austria from January 24, 2012, to June 14, 2017, including follow-ups. Blinded measurements were conducted. A consecutive sample of 143 men was randomized to the treatment group (STICA; n = 72) or wait-list control (WLC) group (n = 71). Main inclusion criteria were male sex and internet addiction as the primary diagnosis. The STICA group had an additional 6-month follow-up (n = 36). Data were analyzed from November 2018 to March 2019.Interventions: The manualized CBT program aimed to recover functional internet use. The program consisted of 15 weekly group and up to 8 two-week individual sessions.Main Outcomes and Measures: The predefined primary outcome was the Assessment of Internet and Computer Game Addiction Self-report (AICA-S). Secondary outcomes were self-reported internet addiction symptoms, time spent online on weekdays, psychosocial functioning, and depression.Results: A total of 143 men (mean [SD] age, 26.2 [7.8] years) were analyzed based on intent-to-treat analyses. Of these participants, 50 of 72 men (69.4%) in the STICA group showed remission vs 17 of 71 men (23.9%) in the WLC group. In logistic regression analysis, remission in the STICA vs WLC group was higher (odds ratio, 10.10; 95% CI, 3.69-27.65), taking into account internet addiction baseline severity, comorbidity, treatment center, and age. Compared with the WLC groups, effect sizes at treatment termination of STICA were d = 1.19 for AICA-S, d = 0.88 for time spent online on weekdays, d = 0.64 for psychosocial functioning, and d = 0.67 for depression. Fourteen adverse events and 8 serious adverse events occurred. A causal relationship with treatment was considered likely in 2 AEs, one in each group.Conclusions and Relevance: Short-term treatment for internet and computer game addiction is a promising, manualized, short-term CBT for a broad range of internet addictions in multiple treatment centers. Further trials investigating the long-term efficacy of STICA and addressing specific groups and subgroups compared with active control conditions are required.Trial Registration: ClinicalTrials.gov identifier: NCT01434589. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation of atrial fibrillation (AF) improves left ventricular (LV) function in patients with LV systolic dysfunction, suggestive of underlying arrhythmia-induced adverse remodeling.Objectives: The objectives of this study were to evaluate whether arrhythmia-induced LV remodeling occurs in patients with AF and preserved LV systolic function and to assess whether this remodeling is reversible after restoration of sinus rhythm by catheter ablation.Methods: Forty-three patients with AF and preserved LV systolic function (LV ejection fraction 62% ± 7%) underwent cardiovascular magnetic resonance (CMR) imaging before catheter ablation including native T1 mapping using a modified Look-Locker inversion recovery sequence. Twenty-five patients underwent follow-up CMR 3 months after catheter ablation. Twenty-two matched controls without AF underwent the same CMR protocol.Results: Patients with AF had higher baseline LV native T1 values than did controls (1296 ± 55 ms vs 1243 ± 55 ms; P < .01). During a median follow-up of 9 months (interquartile range 4-14 months), 17 patients (40%) experienced AF recurrence. No differences in baseline T1 values were observed between patients with and without AF recurrence. There was a significant decrease in native T1 values in patients with successful restoration of sinus rhythm after catheter ablation at 3 months of follow-up CMR (1300 ± 45 ms vs 1270 ± 55 ms; P < .01), while they remain unchanged in patients with AF recurrence (1303 ± 51 ms vs 1309 ± 31 ms; P = .64).Conclusion: These preliminary results suggest that subclinical arrhythmia-induced LV structural remodeling occurs in patients with AF and preserved LV systolic function. This remodeling might be reversible after catheter ablation with successful restoration of sinus rhythm as quantified noninvasively and gadolinium-free by CMR native T1 mapping. [ABSTRACT FROM AUTHOR]

Abstract Objectives This study sought to investigate the potential of the noninvasive albumin-binding probe gadofosveset-enhanced cardiac magnetic resonance (GE-CMR) for detection of coronary plaques that can cause acute coronary syndromes (ACS). Background ACS are frequently caused by rupture or erosion of coronary plaques that initially do not cause hemodynamically significant stenosis and are therefore not detected by invasive x-ray coronary angiography (XCA). Methods A total of 25 patients with ACS or symptoms of stable coronary artery disease underwent GE-CMR, clinically indicated XCA, and optical coherence tomography (OCT) within 24 h. GE-CMR was performed approximately 24 h following a 1-time application of gadofosveset-trisodium. Contrast-to-noise ratio (CNR) was quantified within coronary segments in comparison with blood signal. Results A total of 207 coronary segments were analyzed on GE-CMR. Segments containing a culprit lesion in ACS patients (n = 11) showed significant higher signal enhancement (CNR) following gadofosveset-trisodium application than segments without culprit lesions (n = 196; 6.1 [3.9 to 16.5] vs. 2.1 [0.5 to 3.5]; p < 0.001). GE-CMR was able to correctly identify culprit coronary lesions in 9 of 11 segments (sensitivity 82%) and correctly excluded culprit coronary lesions in 162 of 195 segments (specificity 83%). Additionally, segmented areas of thin-cap fibroatheroma (n = 22) as seen on OCT demonstrated significantly higher CNR than segments without coronary plaque or segments containing early atherosclerotic lesions (n = 185; 9.2 [3.3 to 13.7] vs. 2.1 [0.5 to 3.4]; p = 0.001). Conclusions In this study, we demonstrated for the first time the noninvasive detection of culprit coronary lesions and thin-cap fibroatheroma of the coronary arteries in vivo by using GE-CMR. This method may represent a novel approach for noninvasive cardiovascular risk prediction. Graphical abstract [ABSTRACT FROM AUTHOR]

Abstract Objectives The aims of the study were to assess the prognostic significance of cardiac magnetic resonance myocardial feature tracking (CMR-FT) in a large multicenter study and to evaluate the most potent CMR-FT predictor of hard clinical events following myocardial infarction (MI). Background CMR-FT is a new method that allows accurate assessment of global and regional circumferential, radial, and longitudinal myocardial strain. The prognostic value of CMR-FT in patients with reperfused MI is unknown. Methods The study included 1,235 MI patients (n = 795 with ST-segment elevation MI and 440 with non–ST-elevation MI) at 15 centers. All patients were reperfused by primary percutaneous coronary intervention. Central core laboratory–masked analyses were performed to determine left ventricular (LV) circumferential, radial, and longitudinal strain. The primary clinical endpoint of the study was the occurrence of major adverse cardiac events within 12 months after infarction. Results Patients with cardiovascular events had significantly impaired CMR-FT strain values (p < 0.001 for all). Global longitudinal strain was identified as the strongest CMR-FT parameter of future cardiovascular events and emerged as an independent predictor of poor prognosis following MI even after adjustment for established prognostic markers. Global longitudinal strain provided an incremental prognostic value for all-cause mortality above LV ejection fraction (c-index increase from 0.65 to 0.73; p = 0.04) and infarct size (c-index increase from 0.60 to 0.78; p = 0.002). Conclusions CMR-FT is a superior measure of LV function and performance early after reperfused MI with incremental prognostic value for mortality over and above LV ejection fraction and infarct size. (Abciximab i.v. Versus i.c. in ST-segment elevation Myocardial Infarction [AIDA STEMI]; NCT00712101 ; Thrombus Aspiration in ThrOmbus Containing culpRIT Lesions in Non-ST-Elevation Myocardial Infarction [TATORT-NSTEMI]; NCT01612312) Graphical abstract [ABSTRACT FROM AUTHOR]

Background—Although left atrial (LA) dysfunction is common in heart failure with preserved ejection fraction (HFpEF), its functional implications beyond the reflection of left ventricular (LV) pathology are not well understood. The aim of this study was to further characterize LA function in HFpEF patients. Methods and Results—We performed cardiac magnetic resonance myocardial feature tracking in 22 patients with HFpEF and 12 patients without HFpEF. LA reservoir strain, LA conduit strain, and LA booster pump strain were quantified. Peak oxygen uptake (VO2max) was determined. Invasive pressure–volume loops were obtained to evaluate LV diastolic properties. LV early filling was determined from LV volume–time curves as derived from cardiac magnetic resonance. LA reservoir and conduit strain were significantly lower in HFpEF (LA reservoir strain, 22±7% versus 29±6%, P=0.04; LA conduit strain, −9±5% versus −15±4%, P<0.01). Patients with HFpEF showed lower oxygen uptake (17±6 versus 29±8 mL/ (kg min); P<0.01). Strain measurement for LA conduit function was strongly associated with VO2max (r=0.80; P<0.01). On multivariable regression analysis, LA conduit strain emerged as strongest predictor for VO2max even after inclusion of LV stiffness and relaxation time (β=0.80; P<0.01). LA conduit strain correlated with the volume of early ventricular filling (r=0.67; P<0.01), but not LV stiffness constant β (−0.34; P=0.051) or relaxation constant τ (r=−0.33; P=0.06). Conclusions—Cardiac magnetic resonance myocardial feature tracking–derived conduit strain is significantly impaired in HFpEF and associated with exercise intolerance. Impaired conduit function is associated with impaired early ventricular filling, as potential mechanism leading to impaired oxygen uptake. Our results propose that impaired LA conduit function represents a distinct feature of HFpEF, independent of LV stiffness and relaxation. [ABSTRACT FROM AUTHOR]

Heart failure-induced cardiovascular morbidity and mortality constitute a major health problem worldwide and result from diverse pathogeneses, including coronary artery disease, nonischemic cardiomyopathies, and arrhythmias. Assessment of cardiovascular performance is important for early diagnosis and accurate management of patients at risk of heart failure. During the past decade, cardiovascular magnetic resonance myocardial feature tracking has emerged as a useful tool for the quantitative evaluation of cardiovascular function. The method allows quantification of biatrial and biventricular mechanics from measures of deformation: strain, torsion, and dyssynchrony. The purpose of this article is to review the basic principles, clinical applications, accuracy, and reproducibility of cardiovascular magnetic resonance myocardial feature tracking, highlighting the prognostic implications. It will also provide an outlook on how this field might evolve in the future. [ABSTRACT FROM AUTHOR]

The classification of clinical severity of Ebstein anomaly still remains a challenge. The aim of this study was to focus on the interaction of the pathologically altered right heart with the anatomically—supposedly—normal left heart and to derive from cardiac magnetic resonance (CMR) a simple imaging measure for the clinical severity of Ebstein anomaly.Twenty-five patients at a mean age of 26±14 years with unrepaired Ebstein anomaly were examined in a prospective study. Disease severity was classified using CMR volumes and functional measurements in comparison with heart failure markers from clinical data, ECG, laboratory and cardiopulmonary exercise testing, and echocardiography. All examinations were completed within 24 hours. A total right/left-volume index was defined from end-diastolic volume measurements in CMR: total right/left-volume index=(RA+aRV+fRV)/(LA+LV). Mean total right/left-volume index was 2.6±1.7 (normal values: 1.1±0.1). This new total right/left-volume index correlated with almost all clinically used biomarkers of heart failure: brain natriuretic peptide (r=0.691; P=0.0003), QRS (r=0.432; P=0.039), peak oxygen consumption/kg (r=-0.479; P=0.024), ventilatory response to carbon dioxide production at anaerobic threshold (r=0.426; P=0.048), the severity of tricuspid regurgitation (r=0.692; P=0.009), tricuspid valve offset (r=0.583; P=0.004), and tricuspid annular plane systolic excursion (r=0.554; P=0.006). Previously described severity indices ([RA+aRV]/[fRV+LA+LV]) and fRV/LV end-diastolic volume corresponded only to some parameters.In patients with Ebstein anomaly, the easily acquired index of right-sided to left-sided heart volumes from CMR correlated well with established heart failure markers. Our data suggest that the total right/left-volume index should be used as a new and simplified CMR measure, allowing more accurate assessment of disease severity than previously described scoring systems. [ABSTRACT FROM AUTHOR]

Plaque erosion leads to exposure of subendothelial collagen, which may be targeted by glycoprotein VI (GPVI). We aimed to detect plaque erosion using 64Cu-labeled GPVI-Fc (fragment crystallized).Four-week-old male apolipoprotein E-deficient (ApoE-/-) mice (n=6) were fed a high-fat diet for 12 weeks. C57BL/6J wild-type (WT) mice served as controls (n=6). Another group of WT mice received a ligation injury of the left carotid artery (n=6) or sham procedure (n=4). All mice received a total activity of ≈12 MBq 64Cu-GPVI-Fc by tail vein injection followed by delayed (24 hours) positron emission tomography using a NanoPET/computed tomographic scanner (Mediso, Hungary; Bioscan, USA) with an acquisition time of 1800 seconds. Seventy-two hours after positron emission tomography/computed tomography, all mice were scanned 2 hours after intravenous administration of 0.2 mmol/kg body weight of a gadolinium-based elastin-specific MR contrast agent. MRI was performed on a 3-T clinical scanner (Philips Healthcare, Best, The Netherlands). In ApoE-/- mice, the 64Cu-GPVI-Fc uptake in the aortic arch was significantly higher compared with WT mice (ApoE-/-: 13.2±1.5 Bq/cm3 versus WT mice: 5.1±0.5 Bq/cm3; P=0.028). 64Cu-GPVI-Fc uptake was also higher in the injured left carotid artery wall compared with the intact right carotid artery of WT mice and as a trend compared with sham procedure (injured: 20.7±1.3 Bq/cm3 versus intact: 2.3±0.5 Bq/cm3; P=0.028 versus sham: 12.7±1.7 Bq/cm3; P=0.068). Results were confirmed by ex vivo histology and in vivo MRI with elastin-specific MR contrast agent that measures plaque burden and vessel wall remodeling. Higher R1 relaxation rates were found in the injured carotid wall with a T1 mapping sequence (injured: 1.44±0.08 s-1 versus intact: 0.91±0.02 s-1; P=0.028 versus sham: 0.97±0.05 s-1; P=0.068) and in the aortic arch of ApoE-/- mice compared with WT mice (ApoE-/-: 1.49±0.05 s-1 versus WT: 0.92±0.04 s-1; P=0.028).64Cu-GPVI-Fc positron emission tomographic imaging allows identification of exposed subendothelial collagen in injured WT and high-fat diet-fed ApoE-/- mice. [ABSTRACT FROM AUTHOR]

Rebreather divers use LED-based head-up displays (HUD) as a primary display and warning device for the partial pressure of 02 in the breathing loop. Such devices are usually mounted on the mouthpiece of the rebreather in the field of vision of the diver. LED-based HUDs are simple devices and can be designed so that they are easy to understand but have limited information content. Few alphanumeric or graphical screen-based HUDs have been developed in the past. Connecting such a device to a rebreather requires cable links, which divers dislike, and increases the risk of entanglement. State-of-the-art wireless data transmission uses ultrasonic waves or lowfrequency electromagnetic waves; the former is not silent, and the latter achieves only very low data transmission rates of a few bytes per second and does not meet the antimagnetic standards required by military divers. The present paper describes a novel HUD system that incorporates a simple LED-based primary HUD along with an advanced secondary head-up diving computer with a micro organic LED screen. An optical infrared data transmission system is used to transmit all rebreather relevant data from the primary to the secondary device. One prototype of the system was manufactured and successfully tested in the laboratory according to relevant European standards as well as during several dives in fresh and sea water. [ABSTRACT FROM AUTHOR]

Recreational rebreathers are increasingly popular, and recreational divertraining organizations now routinely offer training for rebreather diving. Few rebreathers on the market, however, fulfill the criteria of a dedicated recreational rebreather. These remain based on traditional sensor technology, which may be linked to rebreather use having an estimated 10 times the risk of mortality while diving compared with open circuit breathing systems. In the present work, a new recreational rebreather based on two innovative approaches is described. Firstly, the rebreather uses a novel sensor system including voltammetric and spectroscopic validation of galvanic p02 sensor cells, a redundant optical p02 sensor, and a two-wavelength infrared pC02 sensor. Secondly, a new breathing loop design is introduced, which reduces failure points, improves work of breathing, and can be mass fabricated at a comparatively low cost. Two prototypes were assembled and tested in the laboratory at a notified body for personal protective equipment before both pool and sea water diving trials. Work of breathing was well below the maximum allowed by the European Normative. These trials also demonstrated that optical p02 sensors can be successfully employed in rebreathers. The pC0M2 sensor detected pC02 from 0.0004 to 0.0024 bar. These new approaches, which include a new concept for simplified mechanical design as well as improved electronic control, may prove useful in future recreational diving apparatus [ABSTRACT FROM AUTHOR]

Objectives: This study sought to compare computed tomography delayed enhancement (CTDE) against cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) for detection of ischemic scar and to test the additive value of CTDE as part of a comprehensive multidetector computed tomography (MDCT) stress–rest protocol including computed tomography perfusion (CTP) and computed tomography angiography (CTA) for the diagnosis of significant coronary artery disease (CAD). Background: CTDE has been recently described as a promising tool for noninvasive detection of myocardial scar, similarly to CMR-LGE techniques. Despite its theoretical potential as an adjunctive tool to improve MDCT accuracy for detection of CAD, its clinical performance has not been validated. Methods: One hundred five symptomatic patients with suspected CAD (age 62.0 ± 8.0 years, 67% men) underwent MDCT, CMR, and x-ray invasive coronary angiography. The MDCT protocol consisted of calcium scoring, stress CTP under adenosine 140 μg/kg/min, rest CTP + CTA, and a low-dose radiation prospective scan for detection of CTDE. CMR-LGE was used as the reference standard for assessment of scar. Functionally significant CAD was defined as the presence of ≥90% stenosis/occlusion or fractional flow reserve measurements ≤0.80 in vessels >2 mm. Results: CTDE had good accuracy (90%) for ischemic scar detection with low sensitivity (53%) but excellent specificity (98%). Positive and negative predictive values were 82% and 91%, respectively. On a patient-based model, MDCT protocol without integration of CTDE results had a sensitivity, specificity, and positive and negative predictive values of 90%, 81%, 80%, and 90%, respectively, for the detection of functionally significant CAD. Addition of CTDE results did not improve MDCT performance (90%, 77%, 77%, and 90%, respectively). Conclusions: CTDE has moderate accuracy for detection of ischemic scar in patients with suspected CAD. Integration of CTDE into a comprehensive MDCT protocol including stress–rest CTP and CTA does not improve MDCT accuracy for detection of significant CAD in intermediate-to-high pre-test probability populations. [Copyright &y& Elsevier]

Cardiovascular magnetic resonance (CMR) myocardial perfusion imaging (MPI) is a state-of-the-art noninvasive modality for detection of myocardial ischemia and coronary artery disease. Magnetic resonance coronary angiography (MRCA) allows visualization of the coronary tree, but its incremental value as part of a CMR protocol including MPI and late gadolinium enhancement (LGE) is not well established. We aimed to evaluate the additive diagnostic value of a 3-dimensional whole-heart MRCA integration into a 1.5T CMR-MPI/LGE protocol for the detection of functionally significant coronary artery disease.Forty-three symptomatic patients (61±8.3 years; 65% men) with suspected coronary artery disease and intermediate/high-pretest probability underwent CMR (including CMR-MPI, MRCA, and LGE) and x-ray invasive coronary angiography (XA) with fractional flow reserve evaluation. Diagnostic performances of MRCA, CMR-MPI/LGE, and MRCA+CMR-MPI/LGE integration were determined having XA+fractional flow reserve as standard for coronary artery disease (≥90% stenosis/occlusion or fractional flow reserve0.80 in vessels>2 mm). MRCA inclusion into the CMR protocol was associated with a mean increase of 7.9±4.69 (0-17.7) minutes in total examination duration (14%). On patient-based analysis, MRCA had 96% sensitivity, 68% specificity, positive predictive value of 79%, and negative predictive value of 93%. CMR-MPI/LGE had 79% sensitivity, 95% specificity, positive predictive value of 95%, and negative predictive value of 78%. Integration of MRCA with CMR-MPI/LGE further improved CMR performance to 96% sensitivity, 89% specificity, positive predictive value of 92%, and negative predictive value of 94%, with a global accuracy of 93%.In this intermediate/high-pretest population, integration of noncontrast-enhanced whole-heart MRCA nonsignificantly improved per-patient diagnostic accuracy of a comprehensive 1.5-T stress-rest CMR-MPI/LGE protocol at a cost of longer scanning times. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to test the hypothesis that transmural perfusion gradients (TPG) on adenosine stress myocardial perfusion cardiac magnetic resonance (CMR) predict hemodynamically significant coronary artery disease (CAD) as defined by fractional flow reserve (FFR). Background: Myocardial ischemia affects the subendocardial layers of the left ventricular myocardium earlier and more severely than the outer layers, and the identification of TPG should be sensitive and specific for the diagnosis of CAD. Previous studies have shown that high spatial resolution myocardial perfusion CMR allows quantitation of TPG between the subendocardium and the subepicardium. Methods: Sixty-seven patients (53 men, age 61 ± 9 years) underwent coronary angiography and high-resolution (1.2 × 1.2-mm in-plane) adenosine stress perfusion CMR at 3.0-T. TPG was calculated for 3 coronary territories. Visual analysis was performed to identify myocardial ischemia. FFR was measured in all vessels with ≥50% severity stenosis. FFR <0.8 was considered hemodynamically significant. In a training group of 30 patients, the optimal threshold of TPG to detect significant CAD was determined (Group 1). This threshold was then tested prospectively in the remaining 37 patients (Group 2). Results: In Group 1, a 20% TPG provided the best diagnostic threshold on both per-segment and per-patient analysis. Applied to Group 2, this threshold yielded a sensitivity of 0.78, specificity of 0.94, and area under the curve of 0.86 for the detection of CAD in a per-segment analysis and of 0.89, 0.83, and 0.86 in a per-patient analysis, respectively. TPG had a similar diagnostic accuracy to visual assessment. Linear regression analysis showed a relationship between TPG and FFR values, with r = 0.63 (p < 0.001). Conclusions: The quantitative analysis of transmural perfusion gradients on high-resolution myocardial perfusion CMR accurately predicts hemodynamically significant CAD as defined by FFR. A TPG diagnostic threshold of 20% is as accurate as visual assessment. [Copyright &y& Elsevier]

Abstract: Background: Direct comparison of CT and magnetic resonance (MR) perfusion techniques has been limited and in vivo assessment is affected by physiological variability, timing of image acquisition, and parameter selection. Objective: We precisely compared high-resolution k-t SENSE MR cardiac perfusion at 3 T with single-phase CT perfusion (CTP) under identical imaging conditions. Methods: We used a customized MR imaging and CT compatible dynamic myocardial perfusion phantom to represent the human circulation. CT perfusion studies were performed with a Philips iCT (256 slice) CT, with isotropic resolution of 0.6 mm3. MR perfusion was performed with k-t SENSE acceleration at 3 T and spatial resolution of 1.2 × 1.2 × 10 mm. The image contrast between normal and underperfused myocardial compartments was quantified at various perfusion and photon energy settings. Noise estimates were based on published clinical data. Results: Contrast by CTP highly depends on photon energy and also timing of imaging within the myocardial perfusion upslope. For an identical myocardial perfusion deficit, the native image contrast-to-noise ratio (CNR) generated by CT and MR are similar. If slice averaging is used, the CNR of a perfusion deficit is expected to be greater for CTP than MR perfusion (MRP). Perfect timing during single time point CTP imaging is difficult to achieve, and CNR by CT decreases by 24%–31% two seconds from the optimal imaging time point. Although single-phase CT perfusion offers higher spatial resolution, MRP allows multiple time point sampling and quantitative analysis. Conclusion: The ability of CTP and current optimal MRP techniques to detect simulated myocardial perfusion deficits is similar. [Copyright &y& Elsevier]

Nowadays, the use of Organic Rankine Cycle (ORC) in decentralised applications is linked with the fact that this process allows to use low temperature heat sources and offers an advantageous efficiency in small-scale applications. Many state of the art applications like geothermal and biomass fired power plants as well as new applications like solar desalination with reverse osmosis, waste heat recovery from biogas digestion plants or micro-Combined Heat and Power (micro-CHP) systems can successfully use the ORC process. The investigation of supercritical parameters in ORC applications seems to bring promising results in decentralised energy production. This paper presents the results from the simulation of the ORC process in normal and supercritical fluid parameters and discusses the efficiency variation in various applications. [ABSTRACT FROM AUTHOR]

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Abstract: Several operating systems provide a central logging service which collects event messages from the kernel and applications, filters them and writes them into log files. Since more than a decade such a system service exists in Microsoft Windows NT. Its file format is well understood and supported by forensic software. Microsoft Vista introduces an event logging service which entirely got newly designed. This confronts forensic examiners and software authors with unfamiliar system behavior and a new, widely undocumented file format. This article describes the history of Windows system loggers, what has been changed over time and for what reason. It compares Vista log files in their native binary form and in a textual form. Based on the results, this paper for the first time publicly describes the key-elements of the new log file format and the proprietary binary encoding of XML. It discusses the problems that may arise during daily work. Finally it proposes a procedure for how to recover information from log fragments. During a criminal investigation this procedure was successfully applied to recover information from a corrupted event log. [Copyright &y& Elsevier]

Abstract: Current tools to analyze memory dumps of systems running Microsoft Windows usually build on the concept of enumerating lists maintained by the kernel to keep track of processes, threads and other objects. Therefore they will frequently fail to detect objects that are already terminated or which have been hidden by Direct Kernel Object Manipulation techniques. This article analyzes the in-memory structures which represent processes and threads. It develops search patterns which will then be used to scan the whole memory dump for traces of said objects, independent from the aforementioned lists. As demonstrated by a proof-of-concept implementation this approach could reveal hidden and terminated processes and threads, under some circumstances even after the system under examination has been rebooted. [Copyright &y& Elsevier]