Diagnostic Value of Global Cardiac Strain in Patients With Myocarditis.

BACKGROUND: Cardiac strain represents an imaging biomarker of contractile dysfunction. PURPOSE: The purpose of this study was to investigate the diagnostic value of cardiac strain obtained by feature-tracking cardiac magnetic resonance (MR) in acute myocarditis. MATERIALS AND METHODS: Cardiac MR examinations of 46 patients with myocarditis and preserved ejection fraction at acute phase and follow-up were analyzed along with cardiac MR of 46 healthy age- and sex-matched controls. Global circumferential strain and global radial strain were calculated for each examination, along with myocardial edema and late gadolinium enhancement, and left ventricle functional parameters, through manual contouring of the myocardium. Correlations were assessed using Spearman ρ. Wilcoxon and Mann-Whitney U test were used to assess differences between data. Receiver operating characteristics curves and reproducibility were obtained to assess the diagnostic role of strain parameters. RESULTS: Global circumferential strain was significantly lower in controls (median, -20.4%; interquartile range [IQR], -23.4% to -18.7%) than patients in acute phase (-18.4%; IQR, -21.0% to -16.1%; P = 0.001) or at follow-up (-19.2%; IQR, -21.5% to -16.1%; P = 0.020). Global radial strain was significantly higher in controls (82.4%; IQR, 62.8%-104.9%) than in patients during the acute phase (65.8%; IQR, 52.9%-79.5%; P = 0.001). Correlations were found between global circumferential strain and global radial strain in all groups (acute, ρ = -0.580, P < 0.001; follow-up, ρ = -0.399, P = 0.006; controls, ρ = -0.609, P < 0.001), and between global circumferential strain and late gadolinium enhancement only in myocarditis patients (acute, ρ = 0.035, P = 0.024; follow-up, ρ = 0.307, P = 0.038). CONCLUSIONS: Cardiac strain could potentially have a role in detecting acute myocarditis in low-risk acute myocarditis patients where cardiac MR is the main diagnosing technique.

Correction to: Point estimate and reference normality interval of MRI-derived myocardial extracellular volume in healthy subjects: a systematic review and meta-analysis.

The original version of this article, published on 02 May 2019, unfortunately contained a mistake. The following correction has therefore been made in the original: The presentation of Fig. 2 was incorrect. The corrected figure is given below. The original article has been corrected.

Point estimate and reference normality interval of MRI-derived myocardial extracellular volume in healthy subjects: a systematic review and meta-analysis.

OBJECTIVES: To estimate the MRI-derived myocardial extracellular volume (ECV) in healthy subjects together with reference normality interval. METHODS: The study was registered on PROSPERO and reported according to PRISMA. In October 2017, a systematic search (MEDLINE/EMBASE) was performed for articles reporting MRI-derived ECV in healthy subjects. The pooled ECV (pECV) with 95% confidence interval (CI) was calculated using the random-effect model; the normality interval was calculated as pECV ± 2 root mean square of all study standard deviations. The Newcastle-Ottawa scale was used for assessing study quality, subgroup/meta-regression analyses for technical/biological covariates, and Egger test for publication bias risk. RESULTS: Of 282 articles, 56 were analyzed totaling 1851 subjects with age 16-68 years, body mass index 23-28 kg/m2, and left ventricular ejection fraction 58-74%. Contrast dose varied from 0.075 to 0.200 mmol/kg. Heterogeneity was high (I2 = 92%). The pECV was 25.6% (95% CI 25.2-26.0%) with a normality interval of 19.6-31.6%. pECV was slightly increasing with age (ß = 0.03%, p = 0.038) and slightly decreasing with the percentage of males (ß = - 0.02%, p = 0.053). Sequence type significantly (p = 0.003) impacted on pECV: the normal interval was 19.9-31.9% for MOLLI and 20.3-33.5% for ShMOLLI. Contrast type/dose, time of acquisition, and magnetic field strength did not significantly impact pECV (p > 0.093). Quality was moderate or high in 48/56 studies (86%). No risk of publication bias (p = 0.728). CONCLUSIONS: Myocardial pECV in healthy subjects was 25.6%, increasing by 0.03% for each year of age. The ECV normality interval was 19.9-31.9% for MOLLI and 20.3-33.5% for ShMOLLI. KEY POINTS: • The pooled estimate of normal MRI-derived ECV based on 1851 subjects was 25.6%, slightly increasing with age and slightly decreasing with the percentage of males. • MRI-derived ECV was independent of contrast type/dose and field strength but dependent on the imaging sequence. • The modeled normality reference interval of MRI-derived ECV was 19.9-31.9% for the MOLLI sequence and 20.3-33.5% for the ShMOLLI sequence.

High-quality low-dose cardiovascular computed tomography (CCT) in pediatric patients using a 64-slice scanner.

Background Cardiovascular computed tomography (CCT) technology is rapidly advancing allowing to perform good quality examinations with a radiation dose as low as 1.2 mSv. However, latest generation scanners are not available in all centers. Purpose To estimate radiation dose and image quality in pediatric CCT using a standard 64-slice scanner. Material and Methods A total of 100 patients aged 6.9 ± 5.4 years (mean ± standard deviation) who underwent a 64-slice CCT scan using 80, 100, or 120 kVp, were retrospectively evaluated. Radiation effective dose was calculated on the basis of the dose length product. Two independent readers assessed the image quality through signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and a qualitative score (3 = very good, 2 = good, 1 = poor). Non-parametric tests were used. Results Fifty-five exams were not electrocardiographically (ECG) triggered, 20 had a prospective ECG triggering, and 25 had retrospective ECG triggering. The median effective dose was 1.3 mSv (interquartile range [IQR] = 0.8-2.7 mSv). Median SNR was 30.6 (IQR = 23.4-33.6) at 120 kVp, 29.4 (IQR = 23.7-34.8) at 100 kVp, and 24.7 (IQR = 19.4-34.3) at 80 kVp. Median CNR was 21.0 (IQR = 14.8-24.4), 19.1 (IQR = 15.6-23.9), and 25.3 (IQR = 19.4-33.4), respectively. Image quality was very good, good, and poor in 56, 39, and 5 patients, respectively. No significant differences were found among voltage groups for SNR ( P = 0.486), CNR ( P = 0.336), and subjective image quality ( P = 0.296). The inter-observer reproducibility was almost perfect (κ = 0.880). Conclusion High-quality pediatric CCT can be performed using a 64-slice scanner, with a radiation effective dose close to 2 mSv in about 50% of the cases.

Detection of incidental cardiac findings in noncardiac chest computed tomography.

The aim of the study was to estimate the rate of incidental cardiac findings (ICF) in patients undergoing noncardiac chest CT.An experienced radiologist retrospectively reviewed 237 consecutive patients (147 males and 90 females with median age of 69 years) undergoing a noncardiac chest CT. ICF at targeted review were compared to those mentioned in original reports (χ test).At review, ≥1 ICF was detected in 124/237 patients (52%), for a total of 229 ICF, 158 of them (69%) not originally mentioned. Valvular calcifications were unmentioned in 23/23 (100%) patients, main pulmonary artery dilation in 21/22 (96%), coronary calcifications in 69/86 (80%), right or left atrial dilation in 7/11 (64%), aortic atherosclerosis in 29/62 (47%), and ascending aorta dilatation in 8/18 (44%). All 6 pericardial effusions were originally mentioned. No association with sex (P ≥ .189); positive correlation with age (P < .001).Half of patients undergoing noncardiac chest CT presented ≥1 ICF, independently from sex but increasing with age. Moreover, 69% of detectable ICFs were not originally mentioned.

Intra- and inter-reader reproducibility of blood flow measurements on the ascending aorta and pulmonary artery using cardiac magnetic resonance.

The aim of our study was to estimate the intra- and inter-reader reproducibility of blood flow measurements in the ascending aorta and main pulmonary artery using cardiac magnetic resonance (CMR) and a semi-automated segmentation method. The ethics committee approved this retrospective study. A total of 50 consecutive patients (35 males and 15 females; mean age±standard deviation 27±13 years) affected by congenital heart disease were reviewed. They underwent CMR for flow analysis of the ascending aorta and main pulmonary artery (1.5 T, through-plane phase-contrast sequences). Two independent readers (R1, trained radiology resident; R2, lower-trained technician student) obtained segmented images twice (>10-day interval), using a semi-automated method of segmentation. Peak velocity, forward and backward flows were obtained. Bland-Altman analysis was used and reproducibility was reported as complement to 100% of the ratio between the coefficient of repeatability and the mean. R1 intra-reader reproducibility for the aorta was 99% (peak velocity), 95% (forward flow) and 49% (backward flow); for the pulmonary artery, 99%, 91% and 90%, respectively. R2 intra-reader reproducibility was 92%, 91% and 38%; 98%, 86% and 87%, respectively. Inter-reader reproducibility for the aorta was 91%, 85% and 20%; for the pulmonary artery 96%, 75%, and 82%, respectively. Our results showed a good to excellent reproducibility of blood flow measurements of CMR together with a semiautomated method of segmentation, for all variables except the backward flow of the ascending aorta, with a limited impact of operator's training.

Fractional flow reserve based on computed tomography: an overview.

Computed tomography coronary angiography (CTCA) is a technique proved to provide high sensitivity and negative predictive value for the identification of anatomically significant coronary artery disease (CAD) when compared with invasive X-ray coronary angiography. While the CTCA limitation of a ionizing radiation dose delivered to patients is substantially overcome by recent technical innovations, a relevant limitation remains the only anatomical assessment of coronary stenoses in the absence of evaluation of their functional haemodynamic significance. This limitation is highly important for those stenosis graded as intermediate at the anatomical assessment. Recently, non-invasive methods based on computational fluid dynamics were developed to calculate vessel-specific fractional flow reserve (FFR) using data routinely acquired by CTCA [computed tomographic fractional flow reserve (CT-FFR)]. Here we summarize methods for CT-FFR and review the evidence available in the literature up to June 26, 2016, including 16 original articles and one meta-analysis. The perspective of CT-FFR may greatly impact on CAD diagnosis, prognostic evaluation, and treatment decision-making. The aim of this review is to describe technical characteristics and clinical applications of CT-FFR, also in comparison with catheter-based invasive FFR, in order to make a cost-benefit balance in terms of clinical management and patient's health.

Novel cardiac magnetic resonance biomarkers: native T1 and extracellular volume myocardial mapping.

Cardiac magnetic resonance (CMR) is a non-invasive diagnostic tool playing a key role in the assessment of cardiac morphology and function as well as in tissue characterization. Late gadolinium enhancement is a fundamental CMR technique for detecting focal or regional abnormalities such as scar tissue, replacement fibrosis, or inflammation using qualitative, semi-quantitative, or quantitative methods, but not allowing for evaluating the whole myocardium in the presence of diffuse disease. The novel T1 mapping approach permits a quantitative assessment of the entire myocardium providing a voxel-by-voxel map of native T1 relaxation time, obtained before the intravenous administration of gadolinium-based contrast material. Combining T1 data obtained before and after contrast injection, it is also possible to calculate the voxel-by-voxel extracellular volume (ECV), resulting in another myocardial parametric map. This article describes technical challenges and clinical perspectives of these two novel CMR biomarkers: myocardial native T1 and ECV mapping.

Four-year cardiac magnetic resonance (CMR) follow-up of patients treated with percutaneous pulmonary valve stent implantation.

OBJECTIVES: To investigate follow-up after percutaneous pulmonary valve implantation (PPVI). METHODS: Forty patients with pulmonary conduit dysfunction (males/females 24/16; 21 ± 08 years; 12 tetralogy of Fallot, 11 aortic valve disease, 17 other congenital heart disease) were planned for CMR before PPVI and repeated 7 times up to 48 months. CMR prospective results regarded: pressure gradient (PG) and regurgitation fraction (RF); end-diastolic volume, end-systolic volume, and stroke volume indexed to body surface area (EDVI, ESVI, and SVI); ejection fraction (EF) of right and left ventricles (RV, LV). A Friedman test was used for comparisons. RESULTS: Overall, PG (31 ± 06 to 16 ± 4 mmHg), RF (16 ± 17 to 0.3 ± 1 %), RVEDVI (82 ± 38 to 58 ± 12 ml/m(2)), and RVESVI (44 ± 12 to 30 ± 13 ml/m(2)) declined (p < 0.001), RVEF (49 ± 13 to 58 ± 12 %) and RVSVI (from 38 ± 14 to 40 ± 8 ml/m(2)) increased (p < 0.001), LVEDVI (67 ± 17 to 73 ± 18 ml/m(2)) and LVSVI (37 ± 11 to 43 ± 10 ml/m(2)) increased (p = 0.034 and p < 0.001). Two patients had valve fracture at 24 and 36 months and underwent surgery. One patient had stent restenosis at 24 months and underwent percutaneous retreatment. Baseline/follow-up CMR did not predict PPVI failure. CONCLUSIONS: CMR demonstrated restored pulmonary conduit function, reduced RV volumes and increased RV and LV function but did not predict valve fracture/restenosis. KEY POINTS: • A CMR 4-year follow-up after PPVI showed restored pulmonary conduit function • RV volumes were significantly reduced • RV function was significantly better in terms of increased EF and SVI • LV function was significantly better in terms of increased EDVI and SVI • Baseline/follow-up CMR did not predict three cases of PPVI failure.

Technical feasibility of real-time elastography to assess the peri-oral region in patients affected by systemic sclerosis.

PURPOSE: To evaluate the technical feasibility of real-time elastography (RTE) to assess the stiffness of the skin of the peri-oral region in patients affected by systemic sclerosis (SSc). METHODS: Six female patients affected by SSc (median age = 52 years) presenting with microstomia and six healthy controls matched for age and sex underwent RTE evaluation of the peri-oral region. Two operators with different experience evaluated the stiffness of the peri-oral region placing the probe in four different positions: parasagittal left (PL), parasagittal right (PR), upper axial (UA), lower axial (LA). Color map was converted into a semi-quantitative scale in which blue = 1, green = 2 and red = 3. Thus, each subject had a variable score ranging from 4 (four positions × value = 1) and 12 (four positions × value = 3). Mann-Whitney U and k statistics were used. RESULTS: RTE demonstrated that the skin of the peri-oral region of patients affected by SSc was stiffer than that of controls, both overall (6;4-6 [median; 25-75th percentile] vs. 11;9-11, p < 0.001) and for each probe position (PL = 1;1-2 vs. 2;2-3, PR = 1;1-2 vs. 2;2-3, UA = 1;1-2 vs. 2;2-3; LA = 1;1-1 vs. 3;3-3, p ≤ 0.011 for all). Interobserver reproducibility was excellent both overall and for each probe position (k = 1). CONCLUSION: RTE is a feasible modality to assess peri-oral region skin stiffness with excellent interobserver reproducibility. Further studies on a larger cohort of patients including more clinical data and measures are warranted to confirm our initial results.

Long-term degradation of poly-lactic co-glycolide/ß-tricalcium phosphate biocomposite anchors in arthroscopic bankart repair: a prospective study.

PURPOSE: To evaluate, using magnetic resonance (MR), the biological efficacy of anchors made of 30% ß-tricalcium phosphate and 70% poly-lactic co-glycolide (PLGA) used for the repair of Bankart lesions after shoulder instability. METHODS: Twenty consecutive patients who were candidates for surgical treatment for unidirectional, post-traumatic shoulder instability were treated arthroscopically with anchors made of 70% PLGA plus 30% ß-tricalcium phosphate preloaded with OrthoCord suture (DePuy Mitek, Raynham, MA). Fifteen of them were evaluated by MR at least 16 months after the intervention. A second evaluation was performed at least 12 months after the first evaluation in the patients in whom implanted anchors were still visible at the first evaluation (n = 5) with a low-intensity signal in all sequences. Two radiologists, with different amounts of experience (15 and 3 years), separately evaluated the MR patterns of the trabecular glenoid bone, the walls of the bone tunnel, and the signal from the anchors. The following parameters were considered in the MR evaluation: integrity of the tunnel edge (grade 0 to 2), intensity of the signal from the anchor site (grade 1 to 3), and presence of cystic lesions. The normal signal from the glenoid trabecular bone has been used as the reference parameter. The anchors were considered independent variables, and thus each one was analyzed individually, even in the same patient. At the final clinical follow-up, a Rowe questionnaire was filled out for each patient. RESULTS: Overall, 44 anchors were evaluated (33 anchors at the first follow-up and 11 anchors at the second follow-up). The mean follow-up period was 28.6 months. With the exception of 2 patients (10%), none of the patients had any episodes of dislocation, having satisfactory postoperative results. No cystic lesions were detected by MR imaging. The interobserver concordance between the 2 radiologists calculated with the Cohen κ was substantial (κ = 0.780 and κ = 0.791 for integrity of tunnel edge and for intensity of signal from anchor site, respectively). Both the integrity of the tunnel border and the intensity of the signal at the site of the anchors that had been implanted more than 24 months before the evaluation were significantly different from those of anchors implanted less than 24 months before the evaluation (tunnel border grade of 0 in 41%, 1 in 50%, and 2 in 9% v 0 in 4.5%, 1 in 50%, and 2 in 45.5% [P = .003]; anchor signal grade of 1 in 41%, 2 in 45.5%, and 3 in 13.5% v 1 in 13.5%, 2 in 41%, and 3 in 45.5% [P = .03]). Analysis of the linear contrasts (analysis of variance) showed a linear increase in the mean values for time to increased tunnel border grade (grade 0, 22 ± 4 months; grade 1, 27 ± 8 months; and grade 2, 29 ± 5 months [P = .02]) and grade of intensity of the signal in the anchor site (grade 1, 24 ± 6 months; grade 2, 26 ± 7 months; and grade 3, 29 ± 7 months [P = .05]). CONCLUSIONS: Anchors made of 30% ß-tricalcium phosphate and 70% PLGA showed excellent biological efficacy, without causing significant cystic lesions, producing gradual changes in the MR signal that seems to become equivalent to that of the glenoid trabecular bone at a mean of 29 months after implantation. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Noncardiac findings in clinical cardiac magnetic resonance: prevalence in 300 examinations after blind reassessment.

PURPOSE: To assess the prevalence of noncardiac findings (NCFs) in a consecutive series of 300 cardiac magnetic resonance (CMR) studies. METHODS: We retrospectively evaluated CMRs of 192 males and 108 females (42 ± 22 years), comparing findings included in reports to those detected after focused reassessment of CMR images. Noncardiac findings were classified as relevant if additional workup was required. RESULTS: We found 19 NCFs, 14 (4.7%) tagged as nonrelevant and 5 (1.7%) as relevant. Images' reassessment presented 45 NCFs, 26 (8.7%) nonrelevant and 16 (5.3%) relevant (P < 0.003). CONCLUSIONS: Cardiac magnetic resonance involves the study of areas larger than the heart alone, and NCFs are found in 1 of 7 patients; more than a half of them are not included in the initial CMR report. A small part is relevant, but detection can be unnecessarily stressful and harmful for patients and could increase costs. Risks of overdiagnosis or underreporting are to be taken into account.