Post-contrast T1 Values Research Articles

Myocardial tissue remodeling in early adult obesity and its association with regional adipose tissue distribution and ectopic fat deposits: a prospective study.

To evaluate the left ventricular (LV) myocardial tissue characteristics in early adult obesity and its association with regional adipose tissue and ectopic fat deposition. Forty-nine obese adults (mean body mass index: 29.9 ± 2.0kg/m2) and 44 healthy controls were prospectively studied. LV native and post-contrast T1 values, extracellular volume fraction (ECV), regional adipose tissue (epicardial, visceral, and subcutaneous adipose tissue (EAT, VAT, and SAT)), and ectopic fat deposition (hepatic and pancreatic proton density fat fractions (H-PDFF and P-PDFF)) based on magnetic resonance imaging were compared. The association was assessed by multivariable linear regression. The obese participants showed reduced global ECV compared to the healthy controls (p < 0.05), but there was no significant difference in global native or post-contrast T1 values between the two groups. Additionally, the obese individuals exhibited higher EAT, VAT, SAT, H-PDFF, and P-PDFF than the controls (p < 0.05). ECV was associated with insulin resistance, dyslipidemia, and systolic blood pressure (SBP) (p < 0.05). Multiple linear regression demonstrated that H-PDFF and SAT were independently associated with ECV in entire population (β = - 0.123 and - 0.012; p < 0.05). Reduced myocardial ECV in patients with mild-to-moderate obesity and its relationship to SBP may indicate that cardiomyocyte hypertrophy, rather than extracellular matrix expansion, is primarily responsible for myocardial tissue remodeling in early adult obesity. Our findings further imply that H-PDFF and SAT are linked with LV myocardial tissue remodeling in this cohort beyond the growth difference and cardiovascular risk factors. Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476). Myocardial fibrosis in severe obesity predicts poor prognosis. We showed that cardiomyocyte hypertrophy, not myocardial fibrosis, is the main myocardial tissue characteristic of early obesity. This finding raises the possibility that medical interventions, like weight loss, may prevent cardiac fibrosis. • Myocardial tissue characteristics in early adult obesity are unclear. • Myocardial extracellular volume fraction (ECV) can be quantitatively evaluated using T1 mapping based on cardiac magnetic resonance imaging (MRI). • Cardiac MRI-derived ECV may noninvasively evaluate myocardial tissue remodeling in early adult obesity.

Features of myocardial characteristics of patients with acute ST-segment elevation myocardial infarction with diabetes mellitus as assessed by contrast-enhanced cardiac magnetic resonance imaging

Introduction. The presence of diabetes mellitus in patients with acute infarction significantly worsens short- and long-term prognosis, but the features of the course of the infarction in this category of patients have not been fully studied.Objective. To compare clinical, functional and structural myocardial characteristics of patients with acute ST-segment elevation myocardial infarction with and without diabetes mellitus.Materials and methods. The study included 91 patients with revascularized ST-segment elevation myocardial infarction (41 patients with diabetes mellitus). All patients underwent cardiac MRI with contrast, including myocardial T1 mapping, tissue analysis of left ventricular myocardium with determination of infarct zone, heterogeneous zone, edema zone, pre- and post-contrast T1 values, extracellular volume values of healthy myocardium and infarct zone.Results. The presence of diabetes in patients with AMI was associated with increased EDV LV: 153 ± 38 and 181 ± 58 ml (p = 0.007), increased ESV LV: 76 ml [54–93] and 87 ml [71–122] (p = 0.035). Infarct size was significantly larger in patients with diabetes than in those without diabetes: 37 ± 15 g (95% CI: 33–41) and 47 ± 21 g (95% CI: 40–53), p = 0.017. Patients with acute infarction and diabetes mellitus had higher extracellular volume values in both healthy myocardium: 24% [22–27] and 28% [24–30], p = 0.002, and in the infarct zone: 48% [40–58] and 58% [50–61], p = 0.016.Conclusions. In patients with ST-segment elevation myocardial infarction with diabetes mellitus, the infarct size, the edema area, and the value of the extracellular volume fraction both in the infarct area and in the preserved myocardium were larger than in patients without diabetes, which may underlie the development of myocardial dysfunction and further progression of heart failure.

Quantitative assessment of extraocular muscles in Graves' ophthalmopathy using T1 mapping.

To evaluate the performance of T1 mapping in the characterization of extraocular muscles (EOMs) of Graves' ophthalmopathy (GO) patients and investigate its feasibility in assessing the response to glucocorticoid therapy in active GO patients. A total of 133 participants (78 active GO, 23 inactive GO, 18 Graves' disease (GD) patients, and 14 healthy volunteers) were consecutively enrolled from July 2018 to December 2020. Native T1 (nT1) and postcontrast T1 (cT1) values of EOMs were measured and compared. The variations in T1 mapping metrics of EOMs were compared pre/post glucocorticoid treatment in 23 follow-up active GO patients. Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed. The nT1 of EOMs in GO patients was higher than that in GD patients and healthy volunteers. The nT1 of superior rectus (SR) in active GO was higher than that in inactive GO patients, and it could be used as a potential marker of GO activity (OR: 1.003; 95% CI: 1.001, 1.004), with a diagnostic sensitivity of 86.3% and specificity of 43.7%. Meanwhile, the cT1 of SR, inferior rectus (IR), and medial rectus (MR) in inactive GO patients were higher than those in active GO patients. The nT1 of EOMs achieved sufficient diagnostic performance in evaluating the response to glucocorticoid therapy for follow-up active GO patients (AUC, 0.797; sensitivity, 71.9%; specificity, 85.7%). T1 mapping could quantitatively assess the activity of GO and the response to glucocorticoid therapy in active GO patients and may even potentially reflect the fibrosis of EOMs. T1 values can reflect the pathological status of the extraocular muscle. T1 mapping could help to quantitatively assess the clinical activity of GO and the response to glucocorticoid therapy in active GO patients. • Graves' ophthalmopathy patients had greater nT1 of extraocular muscles than Graves' disease patients and healthy volunteers, and nT1 of the superior rectus could be a potential marker of Graves' ophthalmopathy activity. • The cT1 of extraocular muscles in inactive Graves' ophthalmopathy patients was higher than that in active Graves' ophthalmopathy patients, and it might be associated with muscle fibrosis. • nT1 of extraocular muscles could offer sufficient diagnostic performance in evaluating the response to glucocorticoid therapy for follow-up active Graves' ophthalmopathy patients.

Early effect of contemporary radiotherapy protocol on myocardium in patients with breast cancer assessed with cardiac magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Medical Centre Ljubljana Research Grant. Introduction Early cardiotoxicity of modern radiotherapy (RT) is not known. Purpose To study the early cardiotoxic effect of contemporary RT on myocardium with cardiac magnetic resonance (CMR) in patients with breast cancer (BC). Methods Patients with in-situ ductal carcinoma of the breast, scheduled for RT were included. All patients had undergone surgical tumorectomy. Exclusion criteria were prior systemic chemotherapy, prior RT or known cardiac disease. Patients were treated with 3-dimensional conformal RT or intensity-modulated RT, left-sided BC patients were also scheduled for deep inspiration breath hold protocol, if feasible. Patients underwent CMR imaging prior to RT and within 2 weeks after RT. Left and right ventricular volumes and ejection fraction, global native and postcontrast T1 values and T2 values, prior to and after completion of RT were analyzed. All patients provided written informed consent. Results A total of 40 female patients (mean age 55 ± 7 years) were included, 22 with left-sided BC. The mean radiation dose was 42 Gy. CMR results are presented in Table 1. Left-sided BC patients had statistically significant increase in global T2 values. There were no significant differences in other studied parameters. No patient developed pericardial effusion and no patient had presence of late gadolinium enhancement at both exams. Conclusion Modern RT of left-sided BC is associated with increased T2 values, most likely representing myocardial edema, early after completion of RT.

T1 and T2 Mapping for Characterization of Mediastinal Masses: A Feasibility study.

Purpose: To evaluate the feasibility and usefulness of T1 and T2 mapping in characterization of mediastinal masses. Methods: From August 2019 through December 2021, 47 patients underwent 3.0-T chest MRI with T1 and post-contrast T1 mapping using modified look-locker inversion recovery sequences and T2 mapping using a T2-prepared single-shot shot steady-state free precession technique. Mean native T1, native T2, and post-contrast T1 values were measured by drawing the region of interest in the mediastinal masses, and enhancement index (EI) was calculated using these values. Results: All mapping images were acquired successfully, without significant artifact. There were 25 thymic epithelial tumors (TETs), 3 schwannomas, 6 lymphomas, and 9 thymic cysts, and 4 other cystic tumors. TET, schwannoma, and lymphoma were grouped together as "solid tumor," to be compared with thymic cysts and other tumors ("cystic tumors"). The mean post-contrast T1 mapping (P < .001), native T2 mapping (P < .001), and EI (P < .001) values showed significant difference between these two groups. Among TETs, high risk TETs (thymoma types B2, B3, and thymic carcinoma) showed significantly higher native T2 mapping values (P = .002) than low risk TETs (thymoma types A, B1, and AB). For all measured variables, interrater reliability was good to excellent (intraclass coefficient [ICC]: .869∼.990) and intrarater reliability was excellent (ICC: .911∼.995). Conclusion: The use of T1 and T2 mapping in MRI of mediastinal masses is feasible and may provide additional information in the evaluation of mediastinal masses.

The use of quantitative T1-mapping to identify cells and collagen fibers in rectal cancer.

This study aimed to explore the value of T1 mapping in assessing the grade and stage of rectal adenocarcinoma and its correlation with tumor tissue composition. Informed consent was obtained from all rectal cancer patients after approval by the institutional review board. Twenty-four patients(14 women and 10 men; mean age, 64.46 years; range, 35 - 82 years) were enrolled in this prospective study. MRI examinations were performed using 3.0T MR scanner before surgery. HE, immunohistochemical, and masson trichrome-staining was performed on the surgically resected tumors to assess the degree of differentiation, stage, and invasion. Two radiologists independently analyzed native T1 and postcontrast T1 for each lesion, and calculated the extracellular volume (ECV) was calculated from T1 values. Intraclass correlation coefficient (ICC) and Bland-Altman plots were applied to analyze the interobserver agreement of native T1 values and postcontrast T1 values. Student's t-test and one-way analysis of variance (ANOVA) were used to test the differences between T1 mapping parameters and differentiation types, T and N stages, and venous and neural invasion. Pearson correlation coefficients were used to analyze the correlation of T1 mapping extraction parameters with caudal type homeobox 2 (CDX-2), Ki-67 index, and collagen expression. Both the native and postcontrast T1 values had an excellent interobserver agreement (ICC 0.945 and 0.942, respectively). Postcontrast T1 values indicated significant differences in venous invasion (t=2.497, p=0.021) and neural invasion (t=2.254, p=0.034). Pearson's correlation analysis showed a significant positive correlation between native T1 values and Ki-67 (r=-0.407, p=0.049). There was a significant positive correlation between ECV and collagen expression (r=0.811, p=.000) and a significant negative correlation between ECV and CDX-2 (r=-0.465, p=0.022) and Ki-67 (r=-0.549, p=0.005). Postcontrast T1 value can be used to assess venous and neural invasion in rectal cancer. ECV measurements based on T1 mapping can be used to identify cells and collagen fibers in rectal cancer.

Multiparametric cardiovascular magnetic resonance characteristics and dynamic changes in asymptomatic heart-transplanted patients.

To describe the dynamic changes in cardiac deformation and tissue characteristics using cardiac magnetic resonance (CMR) in asymptomatic patients during 12 months after heart transplantation (HT). From April 2020 to January 2021, 21 consecutive HT patients without clinical symptoms were included in this prospective study. Multiparametric CMR was performed at 3, 6, and 12 months after HT. Twenty-five healthy volunteers served as controls. During follow-up, a decline in left ventricular (LV) global radial strain (GRS) (p = 0.020) and right ventricular (RV) global longitudinal strain (GLS) (p < 0.001) and an increase in post-contrast T1 (p = 0.024) and T2 (p < 0.001) in asymptomatic HT patients occurred at 3 months, which normalized at 6 months postoperatively, compared with those in healthy controls. A decline in LVGLS (p < 0.001) and LV global circumferential strain (GCS) (p < 0.001) and an increase in native T1 (p < 0.001), T2 (p < 0.001), and extracellular volume (ECV) (p < 0.001) occurred at 3 months. Although most parameters improved gradually, LVGLS, native T1, and ECV remained abnormal compared with those in healthy controls at 12 months; only T2 and LVGCS were normalized at 6 months and 12 months, respectively. ECV was significantly correlated with LVGLS, LVGCS, and LVGRS. Cardiac deformation and tissue characteristics were abnormal early after HT, although the patients were clinically asymptomatic. The dynamic changes in CMR characteristics demonstrate a gradual recovery of myocardial injury associated with transplantation during the first 12 months after HT. • Multiparametric CMR can detect the dynamic changes of transplantation-associated myocardial injury. • Post-contrast T1, T2, LVGRS, and RVGLS values are normalized at 6 months after HT. • Native T1, ECV, and LVGLS values remain abnormal compared with those in healthy controls at 12 months after HT.

Association between Myocardial Iron Overload and Diffuse Myocardial Fibrosis in Thalassemia Major

Cardiovascular magnetic resonance (CMR) is the gold standard for the non-invasive assessment of myocardial tissue properties. All CMR relaxation times (T1, T2 and T2*) are reduced in presence of iron deposits. In the clinical setting the T2* technique is the method of choice for cardiac iron quantification and it has revolutionized the management of patients with thalassemia major (TM). Myocardial extracellular volume( ECV) by CMR has been introduced as a good surrogate imaging marker of diffuse myocardial fibrosis. This the first study to evaluate the association between ECV values and all three relaxation times in TM. 108 β-TM patients (62 females, 40.16±8.83 years), consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network, underwent CMR. T2*, T2, and native and post-contrast T1 values were assessed in all 16 myocardial segments. Segmental ECV values were calculated with input of native and post-contrast myocardial segmental and blood pool T1 values and same-day hematocrit. Global value was the mean of all segmental values. Significant MIO (global heart T2*<20ms) was found in 9 (8.3%) patients. Global ECV values were significantly higher in patients with significant MIO than in patients without significant MIO (40.07±10.62% vs. 31.85±5.71%; p=0.049) (Figure 1A). T2 images were acquired in 90 patients, of whom 40 (44.4%) had a normal global heart T2 value, 9 (8.3%) a reduced global heart T2 value, and 41 (45.6%) an increased global heart T2 value. Patients with reduced global heart T2 value showed significantly higher global ECV values than patients with normal (40.25±9.74% vs 30.54±5.49%; p<0.0001) as well as increased (40.25±9.74% vs 32.63±5.37%; p=0.002) global heart T2 value (Figure 1B). Global heart T1 values were normal in 54 (50%) patients, reduced in 50 (46.3%) patients and increased in 4 (3.7%) patients. Global ECV values tended to be higher among patients with increased T1 value (37.13±4.46%) versus both patients with normal or reduced T1 value (31.84±6.52% and 32.93±6.7%, respectively), but the difference among the three groups was not significant (p=0.259) (Figure 1C). The finding about the increased myocardial ECV in TM patients with reduced global heart T2* value seems to suggest that in TM MIO plays a crucial pathophysiological role in the development of diffuse myocardial fibrosis. This hypothesis is supported by the fact that patients with reduced global heart T2 value showed significantly higher global ECV values than patients with normal or increased global heart T2 value. As TM patients can develop chronic inflammation, the increased myocardial T2 value can be due to myocardial inflammation, that counterbalances the iron effects in non-heavily iron-overloaded hearts. Although myocardial inflammation can affect ECV, confounding the correlation between ECV and fibrosis, the absence of a difference in ECV values between patients with normal and increased global heart T2 value seems to suggest the dominance of fibrosis over inflammation. The absence of a link between decreased T1 and increased ECV may be explained by the fact that although in borderline patients T1 mapping has an higher sensitivity for MIO detection in comparison to the T2* technique, T1 values are not specific for iron and show prolongation in presence of diffuse myocardial fibrosis. Longitudinal prospective studies are needed to clarify the temporal association between myocardial iron overload and diffuse fibrosis and to obtain a better understanding of the implications of the presence of diffuse myocardial fibrosis. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Cardiac MR fingerprinting with a short acquisition window in consecutive patients referred for clinical CMR and healthy volunteers

Cardiac Magnetic Resonance Fingerprinting (cMRF) has been demonstrated to enable robust and accurate T1 and T2 mapping for the detection of myocardial fibrosis and edema. However, the relatively long acquisition window (250 ms) used in previous cMRF studies might leave it vulnerable to motion artifacts in patients with high heart rates. The goal of this study was therefore to compare cMRF with a short acquisition window (154 ms) and low-rank reconstruction to routine cardiac T1 and T2 mapping at 1.5 T. Phantom studies showed that the proposed cMRF had a high T1 and T2 accuracy over a wider range than routine mapping techniques. In 9 healthy volunteers, the proposed cMRF showed small but significant myocardial T1 and T2 differences compared to routine mapping (ΔT1 = 1.5%, P = 0.031 and ΔT2 = − 7.1%, P < 0.001). In 61 consecutive patients referred for CMR, the native T1 values were slightly lower (ΔT1 = 1.6%; P = 0.02), while T2 values did not show statistical difference (ΔT2 = 4.3%; P = 0.11). However, the difference was higher in post-contrast myocardial T1 values (ΔT1 = 12.3%; P < 0.001), which was reflected in the extracellular volume (ΔECV = 2.4%; P < 0.001). Across all subjects, the proposed cMRF had a lower precision when compared to routine techniques, although its higher spatial resolution enabled the visualization of smaller details.

Therapeutic value of tafamidis in patients with wild-type transthyretin amyloidosis (ATTRwt) with cardiomyopathy based on cardiovascular magnetic resonance (CMR) imaging

Abstract Background Tafamidis was approved in Europe for the treatment of cardiomyopathy (CM) in patients with transthyretin amyloidosis (ATTR) in April 2020. So far, real-world data addressing the therapeutic value of tafamidis for the treatment of ATTR-CM are scarce. The purpose of this study was to carefully analyse the therapeutic benefit of tafamidis in patients with wild-type ATTR (ATTRwt) and CM (ATTRwt-CM) after one year of therapy based on serial multi-parametric cardiovascular magnetic resonance (CMR) imaging. Purpose The purpose of this study was to carefully analyse the therapeutic benefit of tafamidis in patients with wild-type transthyretin amyloidosis (ATTRwt) and cardiomyopathy (ATTRwt-CM) after one year of therapy based on serial multi-parametric cardiovascular magnetic resonance (CMR) imaging. Methods The present study comprised N=40 patients with ATTRwt-CM who underwent two serial multi-parametric CMR studies within a follow-up period of 12±3 months. Baseline (BL) clinical parameters, serum biomarkers and CMR findings were compared to follow-up (FU) values in patients with treated “with” tafamidis 61mg daily (n=20, group A) and those “without” tafamidis therapy (n=16, group B). CMR studies were performed on a 1.5-T system and comprised (amongst others) cine-imaging for assessment of cardiac anatomy and function including 3D longitudinal strain assessment. In addition, a modified Look-Locker inversion recovery (MOLLI) T1-mapping sequence was performed for measurement of pre- and post-contrast myocardial T1-values with additional calculation of extracellular volume fraction (ECV)-values. Results While left ventricular ejection fraction (LV-EF), left ventricular mass index (LVMi), left ventricular wall thickness (LVWT), native T1- and ECV-values remained unchanged in the tafamidis group A, a slight reduction in LV-EF (p=0.003) as well as a subtle increase in LVMi (p=0.034), in LVWT (p=0.001), in native T1- (p=0.038) and ECV-values (p=0.017) were observed in the untreated group B. Serum NT-proBNP levels showed an overall increase in both groups, however, with the untreated group B showing a relatively higher increase compared to the treated group A. Assessment of NYHA class did not result in significant intra-group differences when BL were compared with FU, but a trend to improvement in the treated group A compared to a worsening trend in the untreated group B (Δp=0.005). Conclusion Tafamidis does not improve cardiac phenotype in patients with ATTRwt-CM after one year of therapy. However, tafamidis seems to slow down cardiac disease progression in patients with ATTRwt-CM compared to those without tafamidis therapy based on multi-parametric CMR data already after one year of therapy. Funding Acknowledgement Type of funding sources: None.

T1 values and extracellular volume fraction in asymptomatic subjects: variations in left ventricular segments and correlation with cardiovascular risk factors

To evaluate variations in pre-contrast (preT1) and post-contrast (postT1) myocardial T1 values and extracellular volume fraction (ECV) according to left ventricular (LV) segments and to find correlations between them and cardiovascular risk factors. The 233 asymptomatic subjects (210 men, 23 women; aged 54.1 ± 6.0 years) underwent cardiac magnetic resonance imaging with preT1 and postT1 mapping on a 1.5-T scanner. T1 values and ECVs were evaluated according to LV segments, age, sex, and estimated glomerular filtration rate (eGFR). Based on the presence of hypertension (HTN) and diabetes mellitus (DM), subjects were subdivided into the control, HTN, DM, and HTN and DM (HTN-DM) groups. T1 values and ECV showed significant differences between septal and lateral segments at the mid-ventricular and basal levels (p ≤ 0.003). In subgroup analysis, the HTN-DM group showed a significantly higher ECV (0.260 ± 0.023) than the control (0.240 ± 0.021, p = 0.011) and HTN (0.241 ± 0.024, p = 0.041) groups. Overall postT1 and ECV of the LV had significant correlation with eGFR (r = 0.19, p = 0.038 for postT1; r = − 0.23, p = 0.011 for ECV). Septal segments show higher preT1 and ECV but lower postT1 than lateral segments at the mid-ventricular and basal levels. ECV is significantly affected by HTN, DM, and eGFR, even in asymptomatic subjects.

Myocardial Extracellular Volume Fraction Measured by Cardiac Magnetic Resonance Imaging Negatively Correlates With Cardiomyocyte Breadth in a Healthy Porcine Model.

BackgroundThe extracellular volume fraction (ECV) derived from cardiac magnetic resonance imaging (MRI) is extensively used to evaluate myocardial fibrosis. However, due to the limited histological verification in healthy individuals, it remains unclear whether the size of cardiomyocytes may play a potential role in the physiological changes of ECV. The aim of this study was to examine the association between cardiomyocyte size and myocardial ECV by using a healthy porcine model.MethodsSixteen domestic healthy pigs were anesthetized and underwent cardiac MRI with mechanical controlled breathing. Intravenous contrast medium was introduced at a dose of 0.2–0.25 mmol/kg. The interventricular septum ECV was calculated using an established MRI procedure, which was based on the pre- and post-contrast T1 values of the heart and individual blood hematocrit. The cardiomyocyte breadth (CmyB) in cross section was measured by hematoxylin and eosin staining to reflect the cardiomyocyte size.ResultsData were successfully acquired from 14 pigs. The CmyB was obtained from the myocardial tissues corresponding to the region of interest on cardiac MRI. The mean ± SD of the ECV was 0.253 ± 0.043, and the mean ± SD of the CmyB was 10.02 ± 0.84 μm. The ECV exhibited a negative correlation with the CmyB (r = −0.729, p = 0.003).ConclusionThe myocardial ECV detected by cardiac MRI is negatively correlated with the CmyB in healthy pigs, demonstrating that the size of cardiomyocytes is potentially associated with the ECV under physiological conditions.

Feasibility of Hepatic T1-Mapping and Extracellular Volume Quantification on Routine Cardiac Magnetic Resonance Imaging in Patients with Infiltrative and Systemic Disorders

Cardiac magnetic resonance imaging (CMR) is commonly obtained to evaluate for myocardial infiltrative disorders and fibrosis. Pre- and post-Gadolinium contrast T1-mapping sequences are employed to estimate interstitial expansion using extracellular volume fraction (ECV). Given the proximity of the liver to the heart, T1 and ECV quantification of the liver is feasible on CMR. The purpose of this study was to evaluate for hepatic measures of fibrosis and interstitial expansion in patients with amyloidosis or systemic disease on CMR. Myocardial and hepatic native T1 values were measured retrospectively using a cardiac short axis modified Look-Locker inversion recovery sequence. Myocardial and hepatic ECV were calculated using pre- and post-contrast T1 and blood pool values according to the following formula: ECV=(Δ(1/T1) myocardium or liver and/or Δ(1/T1) blood)x(1 - hematocrit). Patients were divided into three cohorts by final diagnosis: amyloidosis, systemic disease (e.g. sarcoid, scleroderma), and controls (EF > 50, no ischemia). Of the 135 patients who underwent CMR, 22 had cardiac amyloidosis (age 59.9 ± 12.6 yrs, 41% female), 20 had systemic disease (age 50.9 ± 13.4 yrs, 35% female), and 93 were controls (age 49.5 ± 17.3 yrs, 50% female). Myocardial T1 and ECV values were highest for patients with amyloid, second highest for systemic disease, and least for controls (T1: 1169 ± 92 vs 1101 ± 53 vs 1027 ± 73 ms, p < 0.0001; ECV: 0.47 ± 0.11 vs 0.31 ± 0.05 vs 0.27 ± 0.04, p < 0.0001). Hepatic T1 and ECV were similarly higher in patients with amyloid and systemic disease compared to controls (T1: 646 ± 101 vs 660 ± 93 vs 595 ± 58 ms, p < 0.0001; ECV: 0.38 ± 0.08 vs 0.37 ± 0.05 vs 0.31 ± 0.03, p < 0.0001). There was a positive correlation between hepatic T1 and ECV (R2=0.282, p < 0.0001). No patients had abnormal liver function tests or clinical liver disease. Hepatic ECV quantification on CMR in patients with amyloidosis and systemic disorders is feasible. Further longitudinal investigation regarding detection of early or subclinical liver disease is warranted.

Cardiac magnetic resonance parametric mapping can detect early cardiac involvement of patients with systemic sclerosis

Abstract Background Systemic sclerosis (SSc) is divided into two subtypes, diffuse and limited cutaneous SSc (dcSSc and lcSSc). The dcSSc subtype has more severe internal organ fibrosis than lcSSc. It is unclear whether cardiovascular magnetic resonance (CMR) parametric mapping can detect early cardiac involvement in these two subtypes. Purpose To detect cardiac involvement and evaluate differences between the two subtypes, we examined CMR parametric mapping. Methods 57 consecutive SSc patients (27 dcSSc and 30 lcSSc) who visited our hospital from July 2018 to February 2021 and underwent CMR at 3.0T (Philips) were included. We analyzed myocardial damage using CMR parametric mapping and compared it with clinical data. Results Mean disease durations of dcSSc and lcSSc were 4.0±6.5 years and 4.4±8.3 years, respectively. Although there were no significant differences in LVEF (56.8±8.8 vs 59.6±7.2), the left and right atrial volume index were significantly larger in dcSSc compared with lcSSc (all p&amp;lt;0.05). Focal fibrosis as evaluated by late gadolinium enhancement was found in 9 SSc patients (15.7%) and 4 patients had pulmonary hypertension. DcSSc patients had significantly higher mid-ventricular native T1 (1350.8±73.2 vs 1312.9±52.1, p=0.029) and postcontrast T1 values (640.4±59.4 vs 604.6±42.5, p=0.015) as compared to lcSSc, although there were no significant differences in ECV and T2 values. Native T1 values in mid-ventricular septum were positively correlated with E/e' ratio of echocardiography in overall SSc patients and dcSSc patients but not in lcSSc patients (r=0.320, p=0.021; r=0.505, p=0.010; r=0.195, p=0.329). Native T1 values in mid-ventricular septum were also positively correlated with plasma levels of brain natriuretic peptide (BNP) in overall SSc patients and dcSSc patients but not in lcSSc patients (r=0.353, p=0.008; r=0.484, p=0.011; r=0.113, p=0.559).The multiple regression analysis considering age and sex revealed that mid-ventricular septum native T1 was the independent predictor of E/e' in SSc patients (β=0.306, p=0.026), and dcSSc patients (β=0.553, p=0.007) but not in lcSSc patients (β=−0.282, p=0.105). The ROC curve for predicting E/e'≥14, cut-off value of native T1 in mid-ventricular septum was ≥1348.5msec (AUC 0.762; 95% CI 0.571–0.953; sensitivity 80.0%; specificity 68.1%). BNP was significantly higher in patients with native T1≥1348.5 msec compared with native T1&amp;lt;1348.5 (102.8±112.8 vs 45.7±55.7; p=0.014). The interobserver variability of CMR parametric mapping values was excellent in this study. Conclusion DcSSc patients showed higher native T1 and larger left and right atrial volume index of CMR than lcSSc patients, suggesting that DcSSc patients had more severe myocardial involvement and left ventricular diastolic dysfunction than lcSSc patients. Early detection of the high native T1 may predict the occurrence of cardiovascular events in the future. Funding Acknowledgement Type of funding sources: None. Correlation between native T1 and BNPCorrelation between native T1 and E/e'

The role of cardiovascular magnetic resonance imaging with T1 and T2 mapping in sudden cardiac death survivors

Abstract Background Sudden cardiac death (SCD) in the adult population is poorly studied, although determining its etiology is crucial for management and prognosis [1]. Cardiovascular magnetic resonance imaging (CMR) is being increasingly utilized in SCD survivors [1,2]. The role of late gadolinium enhancement (LGE) imaging in patients with recent SCD and no significant coronary artery disease (CAD) is well established, but there is no data on the additive role of T1 and T2 mapping [1–3]. Purpose This is a retrospective study to assess the role of CMR including T1 and T2 mapping in SCD survivors. Methods Between 01/2016 and 12/2019, we retrospectively analyzed patients who underwent CMR on a Siemens Magnetom Avanto 1.5 T scanner within 4 weeks of SCD. CMR protocol included cine imaging, T1 and T2 mapping, and LGE imaging. Native and post-contrast myocardial T1 values were measured within the septum on the mid short axis (SAX) and extracellular volume fraction was calculated using the standard formula. T2 values were measured in six mid segments on the mid SAX map. Additional measurements were performed if long axis T2 maps were available. Clinical data, electrocardiography (ECG), transthoracic echocardiography (TTE), coronary computed tomography angiography (CCTA), and left heart catheterization (LHC) were reviewed from the electronic health record. An ischemic evaluation was performed in 33 (94%) of patients. Results A total of 35 patients who underwent CMR for SCD were included for analysis (mean age 46.9±14.1 years; 20 (57%) male). SCD etiology was established based on clinical data, ECG, TTE, CCTA, and LHC in 9 (26%) patients. CMR provided the most probable SCD etiology in an additional 20 (57%) patients with T1 and T2 mapping abnormalities seen in 18 (51%) patients. Diagnoses determined by CMR included myocarditis (35%), hypertrophic cardiomyopathy (CMP) (20%), left ventricular non-compaction CMP (15%), dilated CMP (10%), takotsubo CMP (5%), and myocardial infarction with non-obstructive CAD (15%) (Table, Figure). Elevated native T1 was seen in 15 (43%) (mean T1 1069±60 ms; site specific normal &amp;lt;1080 ms), elevated ECV in 16 (46%) (30±7%; site specific normal &amp;lt;29%), and elevated native T2 in 22 (63%) patients (65±10 ms; site specific normal &amp;lt;60 ms). LGE was present in 31 (89%) patients. The etiology of SCD remained unknown in 6 (17%) patients despite extensive testing including CMR. Conclusions CMR has significant diagnostic and prognostic value in assessing SCD etiology compared to non-CMR based evaluation. Myocarditis is a common underdiagnosed cause of SCD in adult patients well seen in a CMR protocol with T1 and T2 mapping. Myocardial inflammation monitoring in SCD survivors with serial CMRs using T1 and T2 mapping could influence clinical decision making by justifying pharmacotherapy modification and timing of ICD implantation. To conclude, CMR with T1 and T2 mapping provides high diagnostic yield in the investigation of SCD etiology. Funding Acknowledgement Type of funding sources: None.

Quantitative analysis of gadoxetic acid-enhanced MRI for the differential diagnosis of focal liver lesions: Comparison between estimated intralesional gadoxetic acid retention by T1 mapping and conventional processing methods

PurposeTo compare the estimated quantity of intratumor gadoxetic acid retention using T1 mapping of gadoxetic acid-enhanced magnetic resonance imaging (MRI) versus conventional processing methods for the differential diagnosis of focal liver lesions. MethodsSeventy patients with hepatic lesions (colorectal metastasis (CRM) [n = 28], hepatocellular carcinoma (HCC) [n = 20], hemangioma [n = 12], and intrahepatic cholangiocarcinoma (ICC) [n = 10]) underwent gadoxetic acid-enhanced MRI, including pre- and post-contrast T1-weighted imaging and T1 mapping. Quantitative analyses included the lesion-to-liver signal intensity ratio (SIR) on hepatobiliary phase images, the pre- and post-contrast lesion T1 value difference (ΔT1 [ms]), and the lesion retention index (LRI [%]), which was the estimated intralesional gadoxetic acid retention calculated on pre- and post-contrast T1 maps using a two-compartment pharmacokinetic model. Results were compared between the four subcategories of focal liver lesions using the Kruskal-Wallis test, followed by the post-hoc Dunn’s test and receiver operating characteristic (ROC) analysis to distinguish between pairs of the four lesion subcategories. ResultsThis study identified significant differences in the LRI of the four lesion subcategories (p < 0.01), without significant differences in ΔT1 or SIR. Post-hoc analysis demonstrated significant differences in CRM vs. hemangioma (p < 0.01), hemangioma vs. ICC (p < 0.01), and HCC vs. ICC (p = 0.047) for the LRI. ConclusionsThe quantity of intratumor gadoxetic acid retention estimated using pre- and post- contrast T1 mapping could distinguish focal liver lesions, unlike conventional processing methods, and captured unique lesion characteristics.

T1 mapping-derived signature of myocardial involvement in idiopathic inflammatory myopathy compared to acute viral myocarditis: a texture-based analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background. Recent studies revealed the ability of MRI T1 mapping to characterize myocardial involvement in both idiopathic inflammatory myopathy (IIM) and acute viral myocarditis (AVM), as compared to healthy controls. However, neither myocardial T1 nor T2 maps were able to discriminate between IIM and AVM patients, when considering conventional myocardial mean values and derived indices such as lambda and extracellular volume. Purpose. To investigate the ability of T1 mapping-derived texture analysis to differentiate IIM from AVM. Methods. Forty patients, 20 with IIM (51 ± 17 years, 9 men) and 20 with AVM (34 ± 13 years, 16 men) underwent 1.5T MRI T1 mapping using a modified Look-Locker inversion-recovery sequence before and 15 minutes after injection of a gadolinium contrast agent. After manual delineation of endocardial and epicardial borders and co-registration of all inversion time images, native and post-contrast T1 maps were estimated. Myocardial texture analysis was performed on native T1 maps. Textural features such as: autocorrelation, contrast, dissimilarity, energy and sum entropy were used to build a least squares-based linear regression model. Finally, receiver operating characteristic (ROC) analysis was used to investigate the ability of such texture features score to classify IIM vs. AVM patients, compared to the performance of mean myocardial T1. A Wilcoxon rank-sum test was also used to test difference significance between groups. Results. Both native and post-contrast mean myocardial T1 values were comparable between IIM (native: 1022 ± 43 ms; post-contrast: 319 ± 44 ms) and AVM (1056 ± 59 ms, p = 0.07; 318 ± 35 ms, p = 0.90, respectively) groups. Results of ROC analyses are provided in the Table, indicating that a better discrimination between IIM and AVM patients was obtained when using texture features, with higher AUC and accuracy than mean T1 values (Figure). Conclusion. Texture analysis derived from MRI T1 maps without contrast agent injection was able to discriminate between IIM and AVM with higher accuracy, sensitivity and specificity than conventional T1 indices. Such analysis could provide a useful myocardial signature to help diagnose and manage cardiac alterations associated with IIM in patients presenting with myocarditis and primarily suspected of AVM. Table Area under curve (AUC) Accuracy Sensitivity Specificity Native T1 0.67 0.70 0.65 0.75 Post-contrast T1 0.49 0.60 0.25 0.95 Texture features score 0.85 0.82 0.90 0.75 ROC analyses for classification between IIM and AVM patients Abstract Figure

T1 mapping and late gadolinium enhancement for the diagnosis of dilated cardiomyopathy

To explore the role of T1 mapping and late gadolinium enhancement (LGE) for detection of dilated cardiomyopathy (DCM). Thirty-two DCM patients detected by ultrasonic testing with unknown origin heart failure from April 2018 to November 2019 were involved. In addition, they were compared with 18 physical examiner under cardiac magnetic resonance imaging (CMRI) in the same period. Phillip's Ingenia 3.0T MRI was used to examine heart function, plain scan included cine, T2 weighted imaging (T2WI) and pre-contrast native T1 mapping. The enhancement scan included perfusion weighted imaging, LGE imaging and post-contrast post T1 mapping. Using gadolinium injection, a bolus of 0.1 mL/kg of gadolinium-based contrast followed by a 20 mL saline flush was administered. After a 7-minute later start scanning, delay enhance sequence was started, including 4 layers, 2 cavities and 4 cavities. LGE and T1 mapping results were observed, including cardiac function indexes [left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), valvular regurgitation], cardiac morphological indexes [left ventricular mass (LVM)], histological characteristics (T2WI myocardial signal, presence of perfusion defect and its position and scope, presence of delayed enhancement and its position, shape and scope, pre- and post-contrast T1 values), extracellular volume (ECV) and the accompanying signs (pericardial effusion and pleural effusion). The receiver-operating characteristic curve (ROC) was drawn, the diagnostic value of T1 value of pre-contrast T1 mapping for DCM was evaluated, and the occurrence of clinical endpoint events was observed. There were no statistically significant differences in DCM patients with gender, age, body mass index (BMI), blood pressure, heart rate (HR), hematocrit (HCT), creatinine (Cr), family history of hypertension or heart disease. In DCM group N-terminal brain natriuretic peptide precursor (NT-proBNP) level and proportion of patients with heart function level III, diabetes, smoking history, drinking history and medication history were significantly higher than those in control group. Compared with control group, LVEDV (mL/m2: 234.9±35.9 vs. 121.8±27.6), LVESV (mL/m2: 189.7±42.8 vs. 54.8±17.0), LVM (g: 197.6±56.3 vs. 110.5±22.9), pre-contrast T1 values (ms: 1 332.1±35.9 vs. 1 272.0±47.0), ECV [(45.7±4.9)% vs. (28.0±2.1)%] were significantly increased in the DCM group; LVEF (0.191±0.107 vs. 0.554±0.103), post-contrast T1 values (ms: 453.9±72.7 vs. 493.5±43.9) were significantly decreased (all P < 0.05). In DCM group, the proportions of valvular regurgitation, pericardial effusion and pleural effusion were 25.0%, 18.8% and 25.5%, respectively. ROC curve analysis showed that the cutoff value of pre-contrast T1 values was 1 220.22 ms, the area under ROC curve (AUC) was 0.84 (P = 0.015), the sensitivity and specificity were 77.8% and 88.9%, indicating that pre-contrast T1 values may be a certain prediction for diagnosis of DCM. In 32 patients with DCM, 22 cases (68.8%) had LGE in position wall, interventricular septum, inferior wall or under the epicardium, with local or multiple diffuse, 9 cases (28.1%) were both interventricular septum and inferior wall involved. During an average of 16 months follow-up, 3.1% patients appeared sudden cardiac death. One-stop CMRI can improve the diagnostic efficacy of DCM, and T1 mapping with LGE imaging can improve the diagnostic accuracy, which is very meaningful for diagnosis and follow-up of patients.

The effect of gadolinium-based contrast agent administration on magnetic resonance fingerprinting-based T1 relaxometry in patients with prostate cancer

Magnetic resonance fingerprinting (MRF) is a rapidly developing fast quantitative mapping technique able to produce multiple property maps with reduced sensitivity to motion. MRF has shown promise in improving the diagnosis of clinically significant prostate cancer but requires further validation as part of a prostate multiparametric (mp) MRI protocol. mpMRI protocol mandates the inclusion of dynamic contrast enhanced (DCE) imaging, known for its significant T1 shortening effect. MRF could be used to measure both pre- and post-contrast T1 values, but its utility must be assessed. In this proof-of-concept study, we sought to evaluate the variation in MRF T1 measurements post gadolinium-based contrast agent (GBCA) injection and the utility of such T1 measurements to differentiate peripheral and transition zone tumours from normal prostatic tissue. We found that the T1 variation in all tissues increased considerably post-GBCA following the expected significant T1 shortening effect, compromising the ability of MRF T1 to identify transition zone lesions. We, therefore, recommend performing MRF T1 prior to DCE imaging to maintain its benefit for improving detection of both peripheral and transition zone lesions while reducing additional scanning time. Demonstrating the effect of GBCA on MRF T1 relaxometry in patients also paves the way for future clinical studies investigating the added value of post-GBCA MRF in PCa, including its dynamic analysis as in DCE-MRF.

Abstract 14919: Myocardial T 1 Mapping for Prediction of Left Ventricular Reverse Remodeling in Patients With Recent-onset Dilated Cardiomyopathy: a Comparison With Histological Tissue Characterization

Background: Accurate prediction of left ventricular reverse remodeling (LVRR) in dilated cardiomyopathy (DCM) remains challenging. The purpose of this study is to assess the potential of cardiovascular magnetic resonance (CMR) T 1 mapping to predict LVRR by histological confirmation. Methods: Twenty-one DCM patients (12 male, mean age 49 ± 13 years) underwent cine, late gadolinium enhancement (LGE) CMR, and triple-slice T 1 mapping using a modified Look-Locker inversion recovery sequence at 3T before receiving optimal medical therapy. LVRR was defined as an absolute increase in LV ejection fraction (LVEF) from ≥10% to a final value of &gt;35%, accompanied by a decrease in LV end-diastolic volume (LVEDV) ≧10% at midterm (mean time 18 months) CMR follow-up. Extra-cellular volume (ECV) was quantified from pre and post-contrast T 1 values of the blood and myocardium with hematocrit correction. Biopsy samples were used for quantification of collagen volume fraction (CVF). Results: LVRR was observed in 11 patients (52%). The mean native T 1 , ECV, and histological CVF were 1395 ± 49 ms, 0.33 ± 0.03, 0.13 ± 0.04, respectively. Native T 1 yielded comparable ability to ECV measurements for detecting histological CVF (r=0.49, 0.52, both p &lt;0.05). While 14 patients (67%) showed focal scar on LGE, there was no significant difference in histological CVF between patients with and without focal scarring (p=0.6). Native T 1, but not ECV and CVF, correlated well with absolute LVEF increase and relative percent decrease of LVEDV and LV end-systolic volume (r=-0.55, 0.55, 0.56, all p &lt;0.05). Native T 1 &lt;1400 ms provided 90% sensitivity and 82% specificity, with the C-statistic of 0.86 (95% CI 0.64-0.97), for predicting LVRR. On the other hand, the C-statistic of ECV, LGE and histological CVF were 0.72 (95% CI 0.48-0.89), 0.53 (95% CI 0.31-0.75) and 0.66 (95% CI 0.43-0.85), respectively. Conclusions: Myocardial native T 1 have the potential to predict LVRR beyond LGE and histological assessment.