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Copyright of La Radiologia Medica is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of La Radiologia Medica is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A comprehensive whole-body approach to noninvasive evaluation of coronary and extracoronary vasculature is currently not available. The objective of our study was to assess the potential of 64-slice computed tomography angiography (64-CTA) for whole-body evaluation of atherosclerosis burden. Seventy-eight patients referred for coronary imaging underwent whole-body 64-CTA using an adjusted strategy for the administration of contrast medium with dose-saving algorithms involving ECG modulation and reduced tube voltage. Arterial segments (15 coronary, 32 systemic) were evaluated for significant (> or =50%) steno-occlusive disease while arterovenous density was evaluated at seven extracoronary locations. Homogeneous attenuation (mean 321 +/- 20 HU) was obtained throughout the systemic vasculature. Atherosclerosis was observed in 238/995 (24%) coronary and 368/2441 (15%) systemic segments. Significant stenoses/occlusions were present in 214 (21%)/24 (2.5%) coronary segments while asymptomatic clinically relevant stenoses were present in 49 systemic segments. Sensitivity, specificity, positive and negative predictive values of coronary 64-CTA among 52 patients who also underwent quantitative coronary angiography were 92%, 95%, 81% and 98%, respectively. ECG modulation decreased radiation exposure to 14.1-15.4 mSv per patient. Comprehensive, noninvasive assessment of atherosclerosis can be performed by whole-body 64-CTA and may have a positive impact on secondary prevention. [ABSTRACT FROM AUTHOR]

Purpose Extracellular Volume Fraction (ECV) can diagnose cardiac disorders, and is obtainable using T1 mapping. The sensitivity for ECV quantification is limited by the uncertainty affecting T1 measurements. A new methodology for T1 and ECV mapping was here tested, estimating also its level of uncertainty. Methods A reference phantom containing test objects with known T1 values was used, and 60 subjects (40 diseased and 20 healthy) were examined pre- and post-administration of the contrast agent, using a 1.5 T MR tomograph and MOLLI sequences,. A novel algorithm based on a Fast Non-linear Least Squares (FNLS) [1] method was implemented for modelling MR signals, and compared with other well-established methodologies. Gamma-tool analysis, with tolerances criteria of 3% for T1 difference and 4.21 mm for distance-to-agreement was also used to evaluate differences between measured and reference T1 maps. Results Bland-Altman plots and gamma tool analysis evidenced the good agreement among methods. Differences of mean T1 measured by test objects and FNLS algorithm (with respect to reference values) were in the range −3%/2%. The average and maximal standard deviation were 2.3% and 7.4% for the reproducibility with time, and 1.5% and 2.4%for the T1 spatial reproducibility. The ECV error (in terms of error propagation) ranged between 1.0–3.5%. The inter-patient variability range of the ECV value was 23.4%–29.8% for the healthy controls, and 31.0%–53.9% for the diseased patients, showing significant differences between the two groups (p = 0.012). Conclusion The FNLS algorithm is suitable to achieve accurate T1 and ECV mapping. The values of ECV referred to healthy controls were in very good agreement with previously published results. ECV uncertainty, in terms of propagation of T1 errors, were limited and comparable with the healthy control inter-patient variability, confirming the accurate ECV quantification. [ABSTRACT FROM AUTHOR]

Purpose Dynamic Contrast-Enhanced Cardiovascuar Magnetic Resonance Imaging (DCE-CMRI) may quantitatively assess the Myocardial Blood Flow (MBF), recovering the tissue impulse-response function to transit of gadolinium bolus through myocardium. Several deconvolution techniques are available, using various models for the impulse-response [1]. The method choice may influence the results, producing differences that have not been deeply investigated yet. Methods Three methods for quantifying myocardial perfusion were compared: Fermi Function Modeling, Tofts Model, and Gamma Function model, the latter traditionally used in brain perfusion. Thirty human subjects were studied at rest, and Cold Pressor Test stress, injecting a single-bolus of gadolinium of 0.1 mmol/kg. Perfusion estimate differences among methods were analysed by paired comparisons with Student's t-test, linear regression analysis, and Bland-Altman plots, and using also the two-way ANOVA, considering the MBF values of all patients grouped according to two categories: calculation method and rest/stress conditions. Results Perfusion estimates obtained by various methods in both rest and stress conditions were not significantly different, and in agreement with the literature. Results obtained during the first-pass transit time (20 s) yielded p-values in the range 0.20–0.28 for the Student's t-test, slopes from the linear regression analysis between 0.98–1.03, and R values between 0.92–1.01. With the two-way ANOVA, the results were p = 0.20 for the method effect (not significant), p < 0.0001 for the rest/stress condition effect, whereas no interaction resulted between rest/stress condition and method (p = 0.70, not significant). Considering a wider period (60 s), the estimates for both rest and stress conditions were 25–30% higher than those obtained in the 20 s period. Conclusion MBF estimates obtained by various methods at rest/stress condition were not significantly different in the first-pass transit time, encouraging quantitative perfusion estimates in DCE-CMRI with the used methods. [ABSTRACT FROM AUTHOR]

Abstract The pericardium and pericardial diseases in particular have received, in contrast to other topics in the field of cardiology, relatively limited interest. Today, despite improved knowledge of pathophysiology of pericardial diseases and the availability of a wide spectrum of diagnostic tools, the diagnostic challenge remains. Not only the clinical presentation may be atypical, mimicking other cardiac, pulmonary or pleural diseases; in developed countries a shift for instance in the epidemiology of constrictive pericarditis has been noted. Accurate decision making is crucial taking into account the significant morbidity and mortality caused by complicated pericardial diseases, and the potential benefit of therapeutic interventions. Imaging herein has an important role, and cardiovascular magnetic resonance (CMR) is definitely one of the most versatile modalities to study the pericardium. It fuses excellent anatomic detail and tissue characterization with accurate evaluation of cardiac function and assessment of the haemodynamic consequences of pericardial constraint on cardiac filling. This review focuses on the current state of knowledge how CMR can be used to study the most common pericardial diseases.

Residual tissue viability within the infarct area is one of the major determinants of regional functional recovery after acute myocardial infarction, playing also a protective role against LV remodelling. However, viability and functional recovery are not synonymous: functional recovery is only one of the aspects of viability. Several studies have shown how important it is to maintain perfusion independently from functional recovery. In patients with an extensive endocardial necrosis and a preserved normal perfusion in the middle and epicardial myocardium layers, even though functional recovery does not occur, remodelling processes may be attenuated. Tissue viability may be detected using several different methods. Perfusion-based techniques (i.e. PET, SPECT, MRI and MCE) are more accurate in predicting global function and LV remodelling whereas inotropic reserve-based methods (i.e. DE) are more accurate in predicting functional recovery. Several studies support the hypothesis that either LV remodelling or the possibility of myocardial dysfunction to recover are strictly dependent on the extent of microvascular damage. To date, myocardial contrast echocardiography and magnetic resonance imaging have shown to be very effective techniques for assessing microvascular perfusion. Our initial experience showed a very close correlation between these two perfusional techniques. In particular by MCE, it has been demonstrated that the persistence of residual anterograde or retrograde blood flow within the infarct zone can maintain myocardial viability for a prolonged time span. The incidence of LV remodelling is significantly lower in dysfunctioning but still perfused segments than in non-perfused ones. Therefore MCE can be used to identify viable segments that may help to prevent infarct expansion and remodelling, and thus improve patient outcomes. [ABSTRACT FROM AUTHOR]