Extracellular Volume Quantification Research Articles

Myocardial T1 mapping and extracellular volume quantification as novel biomarkers in risk stratification of patients with systemic sclerosis

To study the prognostic value of myocardial native T1 and extracellular volume (ECV), measured by cardiovascular magnetic resonance (CMR), in patients with systemic sclerosis (SSc). Thirty-three SSc patients (16/33 male, 48.5%) were studied using multiparametric CMR including native T1 mapping with ECV calculation, T2 mapping, and late gadolinium enhancement (LGE). Patients were followed-up for cardiac death, haemodynamically significant arrhythmia, or heart failure. Results were compared with 33 age- and gender-matched healthy controls. When compared with controls, SSc patients had higher myocardial native T1 (1,058.9±71 versus 989.4±21.4 ms, p<0.001), higher T2 (54.9±5.7 versus 50±2.5 ms, p<0.001), and ECV values (27.9±5.4% versus 24.8±2%, p<0.004). LGE was present in eight patients (24%), two subendocardial, five midwall, and four subepicardial. LGE, native T1, and ECV were significantly associated with adverse events during follow-up in multivariate Cox regression analysis. Kaplan-Meier analysis demonstrated significant divergence of the survival curves based on the presence of elevated native T1 (≥1,069 ms) or ECV (≥31.4%) values. Cardiac involvement is frequent in SSc. Both native T1 mapping and ECV represent novel non-invasive markers of myocardial fibrosis and could be used in the risk stratification of patients with SSc. CMR mapping may provide a novel biomarker for disease monitoring and study of therapies aiming to reduce myocardial fibrosis in SSc.

Cardiac magnetic resonance imaging for the detection of myocardial involvement in granulomatosis with polyangiitis

The prevalence of undiagnosed cardiac involvement in granulomatosis with polyangiitis (GPA) is unknown. In this prospective study we investigated the utility of cardiovascular magnetic resonance (CMR) to identify myocardial abnormalities in GPA and their correlation with disease phenotype. Twenty-six patients with GPA and no cardiovascular disease or diabetes mellitus underwent contrast-enhanced CMR, including late gadolinium-enhancement (LGE), T1-mapping for native T1 and extra-cellular volume (ECV) quantification for assessment of myocardial fibrosis, cine imaging and tissue tagging for assessment of left ventricular (LV) function. Twenty-five healthy volunteers (HV) with comparable age, sex, BMI and arterial blood pressure served as controls. Patients with GPA had similar cardiovascular risk profile to HV. A focal, non-ischaemic LGE pattern of fibrosis was detected in 24% of patients and no controls (p = 0.010). Patients with myocardial LGE were less frequently PR3 ANCA (7% vs 93%, p = 0.007), and had involvement of the lower respiratory tract and skin. LGE scar mass was higher in patients presenting with renal involvement. Native T1 and ECV were higher in patients with GPA than HV; ECV was higher in those with relapsing disease, and native T1 was inversely associated with PR3 ANCA (β = − 0.664, p = 0.001). Peak systolic strain was slightly reduced in GPA compared to controls; LV ejection function was inversely correlated with disease duration (β = − 0.454, p = 0.026). Patients with GPA have significant myocardial abnormalities on CMR. ANCA, systemic involvement and disease severity were associated with myocardial fibrosis. CMR could be a useful tool for risk stratification of myocardial involvement in GPA.

Quantification of extracellular volume fraction by cardiac computed tomography for noninvasive assessment of myocardial fibrosis in hemodialysis patients

Extent of myocardial fibrosis in hemodialysis patients has been associated with poor prognosis. Myocardial extracellular volume (ECV) quantification using contrast enhanced cardiac computed tomography (CT) is a novel method to determine extent of myocardial fibrosis. Cardiac CT-based myocardial ECV in hemodialysis patients with those of propensity-matched non-hemodialysis control subjects were compared. Twenty hemodialysis patients (mean age, 67.4 ± 9.6 years; 80% male) and 20 propensity-matched non-hemodialysis controls (mean age, 66.3 ± 9.1 years; 85% male) who underwent comprehensive cardiac CT consisted of calcium scoring, coronary CT angiography, stress perfusion CT and delayed enhancement CT were evaluated. Myocardial ECV was significantly greater in the hemodialysis group than in the control group (33.8 ± 4.7% versus 26.6 ± 2.9%; P < 0.0001). In the hemodialysis group, modest correlation was evident between myocardial ECV and left atrial volume index (r = 0.54; P = 0.01), while there was no correlation between myocardial ECV and other cardiac parameters including left ventricular mass index and severity of myocardial ischemia. Cardiac CT-based myocardial ECV may offer a potential imaging biomarker for myocardial fibrosis in HD patients.

Myocardial T1-mapping and Extracellular Volume Quantification in Patients and Putative Carriers of Muscular Dystrophy: Early Experience.

To assess myocardial fibrosis associated with muscular dystrophy, T1-mapping and extracellular volume fraction (ECV) quantification was prospectively performed using cardiovascular MR (CMR) imaging in 6 male patients with muscular dystrophy and 5 female putative carriers of Duchenne or Becker muscular dystrophy. Five patients and all putative carriers had an elevated ECV (>29.5% for men and >35.2% for women), suggesting that ECV has a potential to detect diffuse fibrotic changes in patients and putative carriers of muscular dystrophy.

Myocardial extracellular volume fraction radiomics analysis for differentiation of reversible versus irreversible myocardial damage and prediction of left ventricular adverse remodeling after ST-elevation myocardial infarction.

Our study sought to explore the prognostic value of radiomic TA (texture analysis) on quantitative ECV (extracellular volume) fraction mapping to differentiate between reversible and irreversible myocardial damage and to predict left ventricular adverse remodeling in patients with reperfused STEMI (ST-elevation myocardial infarction). This observational prospective cohort study identified 70 patients (62 ± 9years, 62 men [85.70%]) with STEMI for TA who consecutively performed native and contrast T1 mapping. Texture features were extracted from each stack of ECV mapping based on ROI (region of interest) analysis. After texture feature selection and dimension reduction, five selected texture features were found to be statistically significant for differentiating the extent of myocardial injury. ROC (receiver operating characteristic) curve analysis for the differentiation of unsalvageable infarction and salvageable myocardium demonstrated a significantly higher AUC (area under the curve) (0.91 [95% CI, 0.86-0.96], p < 0.0001) for horizontal fraction than other texture features (p < 0.05). LVAR (left ventricular adverse remodeling) was predicted by those selected features. The differences in qualitative and quantitative baseline parameters and horizontal fractions were significant between the patients with and without LVAR. LGE (late gadolinium enhancement) and horizontal fraction features of infarcted myocardium in acute STEMI were the only two parameters selected in forming the optimal overall multivariable model for LVAR at 6months. Radiomic analysis of ECV could discriminate reversible from irreversible myocardial injury after STEMI. LGE as well as radiomics TA (texture analysis) of ECV may provide an alternative to predict LVAR and functional recovery. • ECV quantification was able to differentiate between infarcted myocardium and non-infarcted myocardium. • Radiomics analysis of ECV could discriminate reversible from irreversible myocardial injury. • Radiomics TA analysis shows a promising similarity with LGE findings which could aid the prognosis of myocardial infarction patients.

Identifying Cardiac Amyloid in Aortic Stenosis: ECV Quantification by CT in TAVR Patients

ObjectivesThe purpose of this study was to validate computed tomography measured ECV (ECVCT) as part of routine evaluation for the detection of cardiac amyloid in patients with aortic stenosis (AS)-amyloid. BackgroundAS-amyloid affects 1 in 7 elderly patients referred for transcatheter aortic valve replacement (TAVR). Bone scintigraphy with exclusion of a plasma cell dyscrasia can diagnose transthyretin-related cardiac amyloid noninvasively, for which novel treatments are emerging. Amyloid interstitial expansion increases the myocardial extracellular volume (ECV). MethodsPatients with severe AS underwent bone scintigraphy (Perugini grade 0, negative; Perugini grades 1 to 3, increasingly positive) and routine TAVR evaluation CT imaging with ECVCT using 3- and 5-min post-contrast acquisitions. Twenty non-AS control patients also had ECVCT performed using the 5-min post-contrast acquisition. ResultsA total of 109 patients (43% male; mean age 86 ± 5 years) with severe AS and 20 control subjects were recruited. Sixteen (15%) had AS-amyloid on bone scintigraphy (grade 1, n = 5; grade 2, n = 11). ECVCT was 32 ± 3%, 34 ± 4%, and 43 ± 6% in Perugini grades 0, 1, and 2, respectively (p < 0.001 for trend) with control subjects lower than lone AS (28 ± 2%; p < 0.001). ECVCT accuracy for AS-amyloid detection versus lone AS was 0.87 (0.95 for 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid Perugini grade 2 only), outperforming conventional electrocardiogram and echocardiography parameters. One composite parameter, the voltage/mass ratio, had utility (similar AUC of 0.87 for any cardiac amyloid detection), although in one-third of patients, this could not be calculated due to bundle branch block or ventricular paced rhythm. ConclusionsECVCT during routine CT TAVR evaluation can reliably detect AS-amyloid, and the measured ECVCT tracks the degree of infiltration. Another measure of interstitial expansion, the voltage/mass ratio, also performed well.

Cardiovascular magnetic resonance for the diagnosis and management of heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF) is characterized by an impaired ventricular filling resulting in the development of dyspnea and other HF symptoms. Even though echocardiography is the cornerstone to demonstrate structural and/or functional alterations of the heart as the underlying cause for the clinical presentation, cardiovascular magnetic resonance (CMR) represents the noninvasive gold standard to assess cardiac morphology, function, and tissue changes. Indeed, CMR allows quantification of biventricular volumes, mass, wall thickness, systolic function, and intra- and extracardiac flows; diastolic functional indices include transmitral and pulmonary venous velocities, left ventricular and left atrial filling velocities from volumetric changes, strain analysis from myocardial tagging, tissue phase contrast, and feature tracking. Moreover, CMR allows superior tissue characterization of the myocardium and the pericardium, which are crucial for a noninvasive etiological and histopathological assessment of HFpEF: conventional T1-weighted, T2-weighted, and post-contrast sequences are now complemented by quantitative mapping sequences, including T1 and T2 mapping as well as extracellular volume quantification. Further experimental sequences comprise diffusion tensor analysis, blood oxygenation-dependent sequences, hyperpolarized contrast agents, spectroscopy, and elastography. Finally, artificial intelligence is beginning to help clinicians deal with an increasing amount of information from CMR exams.

Fibrogenesis and inflammation contribute to the pathogenesis of cirrhotic cardiomyopathy.

Fibrogenesis and inflammation contribute to the progression of cirrhosis. However, it is unknown if these processes also contribute to the development of cirrhotic cardiomyopathy (CCM). Novel magnetic resonance imaging with quantification of the extracellular volume (ECV) provides an estimate of the fibrotic remodelling in the liver and heart. To investigate the relationship between liver and cardiac ECV in cirrhosis and their association with collagen turnover and inflammation. A prospective study of 52 patients with cirrhosis and 14 healthy controls. All patients underwent contrast-enhanced MRI with T1-mapping and quantification of myocardial and liver ECV, biochemical assessments of collagen turnover (PRO-C3, PRO-C5, PRO-C6, collagen type IV degradation fragment, collagen type V degradation fragment, LG1M) and inflammation (TNFα, IL-1β, IL-6, IL-8, IL-18, SDF1α, sCD163, sMR, soluble macrophage mannose receptor). Myocardial and liver ECV were increased in patients compared with healthy controls (myocardial ECV 31.2±5.5% vs 27.4±2.9%, P=0.037; liver ECV 44.1±9.6% vs 33.7±6.7%, P<0.001). Myocardial ECV correlated strongly with liver ECV (r=0.48, P=0.001) and biomarkers of collagen formation and inflammation (P<0.005). Similarly, liver ECV correlated with biomarkers of collagen formation and inflammation (P<0.003). In a multivariate analysis, liver ECV was predicted by biomarkers of collagen formation (PRO-C3 and PRO-C6), whereas myocardial ECV was predicted by biomarkers of collagen formation (PRO-C6) and inflammation (IL-6 and sMR). Structural myocardial changes seem closely related to liver fibrosis in patients with cirrhosis. The strong associations with biomarkers of collagen formation and inflammation provide new insight into the role of inflammation and fibrogenesis in the development of structural cardiac abnormalities, potentially leading to CCM.

DPD Quantification in Cardiac Amyloidosis: A Novel Imaging Biomarker

ObjectivesTo assess whether single-photon emission computed tomography (SPECT/CT) quantification of bone scintigraphy would improve diagnostic accuracy and offer a means of quantifying amyloid burden. BackgroundTransthyretin-related cardiac amyloidosis is common and can be diagnosed noninvasively using bone scintigraphy; interpretation, however, relies on planar images. SPECT/CT imaging offers 3-dimensional visualization. MethodsThis was a single-center, retrospective analysis of 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scans reported using the Perugini grading system (0 = negative; 1 to 3 = increasingly positive). Conventional planar quantification techniques (heart/contralateral lung, and heart/whole-body retention ratios) were performed. Heart, adjacent vertebra, paraspinal muscle and liver peak standardized uptake values (SUVpeak) were recorded from SPECT/CT acquisitions. An SUV retention index was also calculated: (cardiac SUVpeak/vertebral SUVpeak) × paraspinal muscle SUVpeak. In a subgroup of patients, SPECT/CT quantification was compared with myocardial extracellular volume quantification by CT imaging (ECVCT). ResultsA total of 100 DPD scans were analyzed (patient age 84 ± 9 years; 52% male): 40 were Perugini grade 0, 12 were grade 1, 41 were grade 2, and 7 were grade 3. Cardiac SUVpeak increased from grade 0 to grade 2; however, it plateaued between grades 2 and 3 (p < 0.001). Paraspinal muscle SUVpeak increased with grade (p < 0.001), whereas vertebral SUVpeak decreased (p < 0.001). The composite parameter of SUV retention index overcame the plateauing of the cardiac SUVpeak and increased across all grades (p < 0.001). Cardiac SUVpeak correlated well (r2 = 0.73; p < 0.001) with ECVCT. Both the cardiac SUVpeak and SUV retention index had excellent diagnostic accuracy (area under the curve [AUC]: 0.999). The heart to contralateral lung ratio performed the best of the planar quantification techniques (AUC: 0.987). ConclusionsSPECT/CT quantification in DPD scintigraphy is possible and outperforms planar quantification techniques. Differentiation of Perugini grade 2 or 3 is confounded by soft tissue uptake, which can be overcome by a composite SUV retention index. This index can help in the diagnosis of cardiac amyloidosis and may offer a means of monitoring response to therapy.

Myocardial Extracellular Volume Quantification Using Cardiac Computed Tomography: A Comparison of the Dual-energy Iodine Method and the Standard Subtraction Method

To clarify the accuracy of two measurement methods for myocardial extracellular volume (ECV) quantification (ie, the standard subtraction method [ECVsub] and the dual-energy iodine method [ECViodine]) with the use of cardiac CT in comparison to cardiac magnetic resonance imaging (CMR) as a reference standard. Equilibrium phase cardiac images of 21 patients were acquired with a dual-layer spectral detector CT and CMR, and the images were retrospectively analyzed. CT-ECV was calculated using ECVsub and ECViodine. The correlation between the ECV values measured by each method was assessed. Bland-Altman analysis was used to identify systematic errors and to determine the limits of agreement between the CT-ECV and CMR-ECV values. Root mean squared errors and residual values for the ECVsub and ECViodine were also assessed. The correlations between ECVsub and ECViodine for both septal and global measurement were r = 0.95 (p < 0.01) and 0.91 (p < 0.01), respectively, while those between the mean ECVsub and CMR-ECV were r = 0.90 (septal, p < 0.01) and 0.84 (global, p < 0.01), and those between ECViodine and CMR-ECV were r = 0.94 (septal, p < 0.01) and 0.95 (global, p < 0.01). Bland-Altman plots showed lower 95% limits of agreement between ECViodine and CMR-ECV compared with that between ECVsub and CMR-ECV in both septal and global measurement. The root mean squared error of ECVsub was higher than that of ECViodine. The mean residual value of ECVsub was significantly higher than that of ECViodine. ECViodine yielded more accurate myocardial ECV quantification than ECVsub, and provided a comparable ECV value to that obtained by CMR.

Secreted Frizzled-Related Protein 2 and Extracellular Volume Fraction in Patients with Heart Failure.

Background Quantification of extracellular volume (ECV) fraction by cardiovascular magnetic resonance (CMR) has emerged as a noninvasive diagnostic tool to assess myocardial fibrosis. Secreted frizzled-related protein 2 (SFRP2) appears to play an important role in cardiac fibrosis. We aimed to evaluate the association between SFRP2 and myocardial fibrosis and the prognostic value of ECV fraction in patients with heart failure (HF). Methods In this prospective cohort study, 72 hospitalized adult patients (age ≥ 18 years) with severe decompensated HF were included. CMR measurements and T1 mapping were performed to calculate ECV fraction. Serum SFRP2 level was detected by an enzyme-linked immunosorbent assay kit. All patients were followed up, and the primary outcomes were composite events including all-cause mortality and HF hospitalization. Results During the median follow-up of 12 months, 27 (37.5%) patients experienced primary outcome events and had higher levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), SFRP2, and ECV fraction compared with those without events. In Pearson correlation analysis, levels of SFRP2 (r = 0.33), high-sensitivity C-reactive protein (r = 0.31), and hemoglobin A1c (r = 0.29) were associated with ECV fraction (all P < 0.05); however, in multivariate linear regression analysis, SFRP2 was the only significant factor determined for ECV fraction (rpartial = 0.33, P = 0.02). In multivariate Cox regression analysis, age (each 10 years, hazard ratio (HR) 1.13, 95% confidence interval (CI) 1.04–1.22), ECV fraction (per doubling, HR 1.68, 95% CI 1.03–2.74), and NT-proBNP (per doubling, HR 2.46, 95% CI 1.05–5.76) were independent risk factors for primary outcomes. Conclusions Higher ECV fraction is associated with worsened prognosis in HF. SFRP2 is an independent biomarker for myocardial fibrosis. Further studies are needed to explore the potential therapeutic value of SFRP2 in myocardial fibrosis.

Quantification of liver extracellular volume using dual-energy CT: utility for prediction of liver-related events in cirrhosis.

To determine whether quantification of liver extracellular volume fraction (fECV) using dual-energy CT (DECT) allows prediction of liver-related events (LREs) in cirrhotic patients. This retrospective study included 305 cirrhotic patients who underwent dual-source DECT imaging and had serum markers analyzed within 2weeks of initial CT imaging. The fECV score was measured using an iodine map of equilibrium-phase images obtained 3min after contrast injection at 100/140 Sn kVp. The association of the fECV score and serum markers with LREs was investigated. A risk model combining the fECV score (< 27 versus ≥ 27%) and serum albumin level (< 4 versus ≥ 4g/dL) was constructed for LRE prediction. An increased fECV score (odds ratio, 1.27; 95% confidence interval (CI), 1.15, 1.40) was independently associated with decompensated cirrhosis at baseline (n = 85) along with the Model for End-Stage Liver Disease score (odds ratio, 1.32; 95% CI, 1.07, 1.63). Among patients with compensated cirrhosis, 10.5% (23 of 220) experienced LREs during the median follow-up period of 2.0years (decompensation, n = 14; hepatocellular carcinoma, n = 9). The fECV score (hazard ratio, 1.40; 95% CI, 1.22, 1.62) and serum albumin level (hazard ratio, 0.26; 95% CI, 0.09, 0.73) were independent predictors of LRE. The mean times to LRE among the high (16.5months, n = 18)-, intermediate (25.6months, n = 44)-, and low (30.5months, n = 158)-risk groups were significantly different (p < 0.001). The fECV score derived from DECT allows prediction of LREs in cirrhotic patients. • The extracellular volume fraction (fECV) score derived from the iodine map of dual-energy CT (DECT) was independently associated with the presence of hepatic decompensation. • The fECV score derived from the iodine map of DECT can predict liver-related events (LREs) in patients with cirrhosis. • Equilibrium-phase scanning in dual-energy mode is recommended as part of liver CT in cirrhotic patients because it can provide a prognostic indicator for LRE development.

Automated Myocardial T2 and Extracellular Volume Quantification in Cardiac MRI Using Transfer Learning-based Myocardium Segmentation.

To assess the performance of an automated myocardial T2 and extracellular volume (ECV) quantification method using transfer learning of a fully convolutional neural network (CNN) pretrained to segment the myocardium on T1 mapping images. A single CNN previously trained and tested using 11 550 manually segmented native T1-weighted images was used to segment the myocardium for automated myocardial T2 and ECV quantification. Reference measurements from 1525 manually processed T2 maps and 1525 ECV maps (from 305 patients) were used to evaluate the performance of the pretrained network. Correlation coefficient (R) and Bland-Altman analysis were used to assess agreement between automated and reference values on per-patient, per-slice, and per-segment analyses. Furthermore, transfer learning effectiveness in the CNN was evaluated by comparing its performance to four CNNs trained using manually segmented T2-weighted and postcontrast T1-weighted images and initialized using random-weights or weights of the pretrained CNN. T2 and ECV measurements using the pretrained CNN strongly correlated with reference values in per-patient (T2: R = 0.88, 95% confidence interval [CI]: 0.85, 0.91; ECV: R = 0.91, 95% CI: 0.89, 0.93), per-slice (T2: R = 0.83, 95% CI: 0.81, 0.85; ECV: R = 0.84, 95% CI: 0.82, 0.86), and per-segment (T2: R = 0.75, 95% CI: 0.74, 0.77; ECV: R = 0.76, 95% CI: 0.75, 0.77) analyses. In Bland-Altman analysis, the automatic and reference values were in good agreement in per-patient (T2: 0.3 msec ± 2.9; ECV: -0.3% ± 1.7), per-slice (T2: 0.1 msec ± 4.6; ECV: -0.3% ± 2.5), and per-segment (T2: 0.0 msec ± 6.5; ECV: -0.4% ± 3.5) analyses. The performance of the pretrained network was comparable to networks refined or trained from scratch using additional manually segmented images. Transfer learning extends the utility of pretrained CNN-based automated native T1 mapping analysis to T2 and ECV mapping without compromising performance. Supplemental material is available for this article. © RSNA, 2020.

Quantification of myocardial interstitial fibrosis and extracellular volume for the detection of cardiac allograft vasculopathy.

In search of a non-invasive alternative detection of early-stage cardiac allograft vasculopathy (CAV), in this preliminary study we tested the hypothesis that interstitial fibrosis quantified with cardiac magnetic resonance (CMR) can serve as a biomarker for the detection of CAV. Late-stage CAV was detected with routine X-ray coronary angiography (XRCA), while a coronary intima-media thickness ratio (IMTR) > 1 on optical coherence tomography (OCT) was used to detect early-stage CAV. Interstitial fibrosis was quantified in the endomyocardial biopsy (EMB) and indirectly with CMR as the T1 relaxation time and extracellular volume (ECV). CMR was performed within 48h of a single invasive procedure with XRCA, OCT, and EMB procurement in stable HTx recipients (n = 27; age 54 ± 13years, 5.4 ± 3.7years post-transplant). XRCA-CAV and IMTR > 1 were present in 15% and 75% of study patients, respectively. The T1 relaxation times and ECV were increased in patients with XRCA-CAV (p = 0.03 each), while IMTR and EMB interstitial fibrosis were not significantly different (both p > 0.05). ECV (ρ = 0.46, p = 0.02) and IMTR (ρ = 0.58; p = 0.01) correlated with the histological quantity of interstitial fibrosis, while the T1 relaxation time (p = 0.06) did not. The correlation of the IMTR with the EMB interstitial fibrosis tentatively validates the hypothesis that interstitial fibrosis may serve as an early indicator of CAV. Moreover, the significant association of CMR-based ECV with the magnitude of interstitial fibrosis in the biopsy suggests ECV as a potential biomarker for interstitial fibrosis due to early-stage CAV. The measurement of ECV may therefore have a role for non-invasive detection and follow-up of early-stage CAV.

P5281Synthetic extracellular volume quantification by cardiac magnetic resonance imaging - a reliable tool in clinical practice?

Abstract Background Extracellular volume (ECV) quantification by CMR imaging allows the measurement of changes in the extracellular space indicating diffuse edema and fibrosis, especially in early stages of myocardial disease. Usually venous hematocrit (Hct) is needed in order to calculate standard ECV. Recent findings suggest the alternative use of the blood pool T1-relaxation time (T1blood) instead of the venous Hct to generate “synthetic Hct ” and furthermore “synthetic ECV”, allowing a more routine and user-friendly application without the need of a current blood sample. Purpose Purpose of this study is to re-evaluate whether the connection between venous Hct and T1blood can be used to generate a synthetic ECV in a large number of volunteers and patients with various myocardial diseases from a tertiary care centre. Methods 945 volunteers and patients were divided into a derivation (n=490) and a validation group (n=455). Standard ECV was calculated using T1-relaxtion times acquisitioned in the septal myocardium and blood pool, each on pre- and post-contrast Images using a modified look-locker sequence at a 3 Tesla MR-scanner. In addition venous Hct was measured in a blood sample drawn prior to the scan. Synthetic Hct was derived through linear regression analysis between venous Hct and 1/T1blood and was then compared to venous Hct. Also we derived standard ECV and synthetic ECV and examined these using Lin's rho and Bland-Altman comparison. Results In the derivation group venous Hct and 1/T1blood showed a linear relationship (R2=0,22; p=ehz746.02521). This was used to calculate synthetic Hct and synthetic ECV. Synthetic ECV correlated well with standard ECV (Lin's rho= 0,903; p&lt;0,0001). Mean difference 0,004, limits of agreement −0,038 and 0,047. See table 1 for patient characteristics and figure 1 for Bland-Altman plot on standard and synthetic ECV. Table 1. Patient characteristics Sex female (%) 312 (33%) Age, yrs 60±15 EDVi, ml/m2 86±31 ESVi, ml/m2 43±30 LVEF, % 54±16 Hematocrit, % 43±5 Figure 1 Conclusion Despite only weak correlation of synthetic and venous Hct we found excellent correlation in synthetic and standard ECV. Therefore we could confirm the value of synthetic ECV in a large cohort of volunteers and patients, providing a feasible and non-invasive marker for extracellular myocardial alterations in everyday clinical practice.

Cardiac dysfunction in cirrhosis: a 2-yr longitudinal follow-up study using advanced cardiac imaging.

The temporal relationship between cirrhotic cardiomyopathy, progression of liver disease, and survival remains unknown. Our aim was to investigate the development of structural and functional cardiac changes over time with the progression of cirrhosis and outcome. Sixty-three cirrhotic outpatients (Child class: A = 9, B = 46, C = 8) and 14 healthy controls were included in this 2-yr longitudinal study. Advanced cardiac characteristics such as cardiac MRI with extracellular volume (ECV) quantification, speckle tracking echocardiography, and biomarkers were assessed at 0/6/12/18/24 mo. Patients were followed-up for a median of 30 mo with registration of acute decompensations (ADs), liver transplantations (LTs), and deaths. Patients who progressed, underwent LT or died had more pronounced cardiac dysfunction, structural myocardial changes, and left atrial enlargement. Conversely, limited cardiac deterioration was seen in patients who remained stable or improved in cirrhosis. During follow-up 25 patients developed AD, 4 underwent LT, and 20 died. Mean arterial pressure was the only cardiovascular parameter associated with death in a univariate analysis (P = 0.037), and the main predictors were model for end-stage liver disease and age. However, last-visit myocardial ECV was independently associated with the combined end point of LT/death (P = 0.001), and in patients with AD a low cardiac index was independently associated with death (P = 0.01). Cardiac function seems to deteriorate with the progression of cirrhosis and affects prognosis, especially in patients with AD. Conversely, patients with stable cirrhosis have limited progression in cardiac dysfunction over a 2-yr period with modest impact on survival. The results encourage careful cardiac monitoring in advanced cirrhosis.NEW & NOTEWORTHY For the first time, we have performed advanced cardiac imaging to investigate the development of cirrhotic cardiomyopathy over 2 years. We show that cardiac dysfunction deteriorates with progression of cirrhosis and may affect the prognosis in patients developing acute decompensation. Especially, structural myocardial abnormalities, left atrial enlargement, and a hypodynamic cardiac state seem of importance. Conversely, limited cardiac progression is seen in stable cirrhosis. These findings provide new insight into our understanding of cirrhotic cardiomyopathy.

Mapping versus source methods for quantifying myocardial T1 in controls and in repaired tetralogy of Fallot: interchangeability and reproducibility in children

Myocardial T1 relaxometry can be performed by contouring on individual T1-weighted source images (source method) or on a single T1 map (mapping method). This study compares (a) agreement between native T1 and extracellular volume results of the two methods and (b) interobserver reproducibility of the two methods in children without heart disease and those with tetralogy of Fallot (TOF). We retrospectively analyzed pediatric patients (controls and those with repaired TOF) with cardiac magnetic resonance examinations including extracellular volume quantification using the modified Look-Locker inversion recovery (MOLLI) sequence. We compared native T1 and extracellular volume of the entire left ventricle and interventricular septum derived using the source and the mapping approaches. In the control group (n=25, median age 14.0years, interquartile range [IQR] 11.5-16.5years), the mapping method produced lower native T1 values than the source method in the interventricular septum (mean difference ± standard deviation [SD] = 12±15ms, P<0.001). In the TOF group (n=50, median age 13.3years, IQR 9.9-15.0years), the mapping method produced lower values for native T1 and extracellular volume in the interventricular septum (mean difference 9±14ms and 0.6±1.1%, P<0.001). In 6-12% of the children, differences were >3 standard deviations from the mean difference. Interobserver reproducibility between the two methods by intraclass correlation coefficients were clinically equivalent. T1 and extracellular volume values generated by the source and mapping methods show systematic differences and can vary significantly in an individual child, and thus cannot be used interchangeably in clinical practice. The source method might allow for easier detection and, in some cases, mitigation of artifacts that are not infrequent in children and can be difficult to appreciate on the T1 map.

Cardiovascular magnetic resonance with parametric mapping in long-term ultra-marathon runners

PurposeThere is a direct reverse dose-effect relationship between the amount of physical activity and cardiovascular risk. It is unknown whether this is true for extreme, persistent endurance training. The aim of the study was to assess structural changes of the heart in long-time ultra-marathon runners with special focus on myocardial fibrosis using parametric mapping. MethodWe studied a group of 30 healthy, male ultra-marathon runners (mean age 40.9 ± 6.6 yrs, median 9 yrs of running with frequent competitions) and 10 matched controls not engaged in any regular activities. All of them underwent cardiovascular magnetic resonance (CMR) with 3 T scanner including T1-mapping, late gadolinium enhancement (LGE) and extracellular volume (ECV) quantification. ResultsAthletes demonstrated significantly larger heart chambers and left ventricular (LV) mass. LV systolic function was unchanged. 73.3% of athletes fulfilled volumetric criteria for dilated cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy. Non-ischemic, small volume LGE was found in 8 athletes and in 1 control (27% vs. 10%, p = 0.40). It was localised at insertion points (5 athletes, 1 control) or in the septum or infero-lateral wall (3 athletes). Athletes with insertion point LGE had higher right ventricular end-diastolic volume index in comparison to athletes without LGE (p = 0.04), which suggests its relation to volume overload. There were no differences between athletes and non-athletes in terms of ECV values (26.1% vs. 25%, p = 0.29). ConclusionsUltra-marathon runner's hearts demonstrate a high degree of structural remodelling, but there is no significant increase in focal or diffuse myocardial fibrosis.

Myocardial Late Iodine Enhancement and Extracellular Volume Quantification with Dual-Layer Spectral Detector Dual-Energy Cardiac CT

To explore the usefulness of myocardial late iodine enhancement (LIE) and extracellular volume (ECV) quantification by using dual-energy cardiac CT. In this single-center retrospective study, a total of 40 patients were evaluated with LIE CT by using a dual-layer spectral detector CT system. Among these, 21 also underwent cardiac MRI. Paired image sets were created by using standard imaging at 120 kVp, virtual monochromatic imaging (VMI) at 50 keV, and iodine density imaging. The contrast-to-noise ratio and image quality were then compared. Two observers assessed the presence of LIE and calculated the interobserver agreements. Agreement between CT and cardiac MRI when detecting late-enhancing lesions and calculating the ECV was also assessed. The contrast-to-noise ratio was significantly higher by using VMI than by using standard 120-kVp imaging, and the mean visual image quality score was significantly higher by using VMI than by using either standard or iodine density imaging. For interobserver agreement of visual detection of LIE, the agreement for VMI was excellent and the κ value (κ, 0.87) was higher than that for the standard 120-kVp (κ, 0.70) and iodine density (κ, 0.83) imaging. For detecting late-enhancing lesions, agreement with cardiac MRI was excellent by using VMI (κ, 0.90) and iodine density imaging (κ, 0.87) but was only good by using standard 120-kVp imaging (κ, 0.66). Quantitative comparisons of the ECV calculations by using CT and cardiac MRI showed excellent correlation (r 2 = 0.94). Dual-energy cardiac CT can assess myocardial LIE and quantify ECV, with results comparable to those obtained by using cardiac MRI.© RSNA, 2019See also the commentary by Litt in this issue.

Diffuse myocardial fibrosis in adolescents operated with arterial switch for transposition of the great arteries - A CMR study

Diffuse myocardial fibrosis in adolescents operated with arterial switch for transposition of the great arteries - A CMR study