Myocardial T1 maps reflect histological findings in acute and chronic stages of myocarditis in a rat model

Prognostic value of cardiovascular magnetic resonance in immune checkpoint inhibitor-associated myocarditis: A systematic review and meta-analysis

Background

Immune checkpoint inhibitors (ICI) are increasingly used in the first-line treatment of malignant tumors. There is increasing recognition of their cardiotoxicity and, in particular, their potential to lead to myocarditis. Cardiovascular magnetic resonance (CMR) can quantify pathological changes, such as myocardial edema and fibrosis. The purpose of this systematic review and meta-analysis was to examine the evidence for the roles of CMR in predicting prognosis in ICI-associated myocarditis.

Methods

PubMed, Cochrane Library, and Web of Science databases were searched until October 2023 for published works investigating the relationship between CMR parameters and adverse events in patients with ICI-associated myocarditis. The analysis included studies reporting the incidence of late gadolinium enhancement (LGE), T1 values, T2 values, and CMR-derived left ventricular ejection fraction (LVEF). Odds ratios (OR) and weighted mean differences (WMD) were combined for binary and continuous data, respectively. Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies.

Results

Five cohort studies were included (average age 65-68 years; 25.4% female). Of these, four studies were included in the meta-analysis of LGE-related findings. Patients with major adverse cardiovascular events (MACE) had a higher incidence of LGE compared with patients without MACE (OR = 4.18, 95% CI: 1.72-10.19, p = 0.002). A meta-analysis, incorporating data from two studies, showed that patients who developed MACE exhibited significantly higher T1 value (WMD = 36.16 ms, 95% CI: 21.43-50.89, p < 0.001) and lower LVEF (WMD = - 8.00%, 95% CI: -13.60 to -2.40, p = 0.005). Notably, T2 value (WMD = -0.23 ms, 95% CI: -1.86 to -1.39, p = 0.779) was not associated with MACE in patients with ICI-related myocarditis.

Conclusions

LGE, T1 value, and LVEF measured by CMR imaging have potential prognostic value for long-term adverse events in patients with ICI-related myocarditis.

Early detection and serial monitoring during chemotherapy-radiation therapy: Using T1 and T2 mapping cardiac magnetic resonance imaging

Purpose

To confirm the ability of native T1 and T2 values in detecting and monitoring early myocardial injuries of chest radiotherapy in neoplasm patients.

Materials and methods

Fifteen participants received non-anthracycline chemotherapy and chest radiotherapy, and 30 age/gender-matched controls were enrolled in this prospective study. Cardiac magnetic resonance scans were performed within 2 days, 3 months, and 6 months after chest radiotherapy. Myocardial native T1 and T2 values were measured in irradiated and nonirradiated areas. Meanwhile, the parameters of left ventricular function and left ventricular myocardial strain were obtained.

Results

There were no significant differences in left ventricular function, native T1, T2, and strain between patients and controls before chest radiotherapy. In 15 participants who were followed up for 6 months, there was a significant change only in left ventricular ejection fraction (LVEF) among baseline and the first follow-up (P = 0.021), while the adjusted P-value was higher than 0.05 after Bonferroni correction, as well as other parameters. Native T1 values were elevated at 3 and 6 months in irradiated areas compared with baseline (1,288.72 ± 66.59 ms vs. 1,212.51 ± 45.41 ms; 1,348.01 ± 54.16 ms vs. 1,212.51 ± 45.41 ms; P &lt; 0.001 for both). However, T2 values only changed at 3 months in irradiated areas compared with baseline (44.21 ± 3.35 ms vs. 39.14 ± 1.44 ms; P = 0.006). Neither the native T1 nor T2 values changed in nonirradiated areas during the follow-up period (all P &gt; 0.05). There were no significant differences in strain changes during the follow-up period (all P &gt; 0.05).

Conclusion

Native T1 and T2 values elevated at 3 months after chest radiotherapy, whereas LVEF showed no significant change during the 6-month follow-up.

Emerging Role of Cardiac Magnetic Resonance Imaging in Diagnosing Myocarditis: A Blunder or The Way To Get the Problem Sorted?

Acute myocarditis is a disease affecting the myocardial tissue, which is caused by infections, rheumatic diseases, especially sarcoidosis, or certain therapies. Its diagnosis may be difficult, owing to its variable clinical presentation. In this setting, cardiac magnetic resonance plays a pivotal role in detecting myocardial inflammation through qualitative, semiquantitative, and quantitative parameters, in particular with the new quantitative techniques such as T1 and T2 mapping, combined or not with late gadolinium enhancement evaluation. This is in accordance with the revised Lake Louise criteria. In this review, the emerging role of the new cutting-edge cardiac magnetic resonance imaging techniques in diagnosing myocarditis is extensively presented.

Cardiac MRI Depicts Immune Checkpoint Inhibitor-induced Myocarditis: A Prospective Study

Background Immune checkpoint inhibitors (ICIs) for cancer treatment are associated with a spectrum of immune-related adverse events, including ICI-induced myocarditis; however, the extent of subclinical acute cardiac effects related to ICI treatment is unclear. Purpose To explore the extent of cardiac injury and inflammation related to ICI therapy that can be detected with use of cardiac MRI. Materials and Methods In this prospective study from November 2019 to April 2021, oncologic participants, without known underlying structural heart disease or cardiac symptoms, underwent multiparametric cardiac MRI before planned ICI therapy (baseline) and 3 months after starting ICI therapy (follow-up). The cardiac MRI protocol incorporated assessment of cardiac function, including systolic myocardial strain, myocardial edema, late gadolinium enhancement (LGE), T1 and T2 relaxation times, and extracellular volume fraction. The paired t test, Wilcoxon signed-rank test, and McNemar test were used for intraindividual comparisons. Results Twenty-two participants (mean age ± standard deviation, 65 years ± 14; 13 men) were evaluated, receiving a median of four infusions of ICI therapy (interquartile range, four to six infusions). Compared with baseline MRI, participants displayed increased markers of diffuse myocardial edema at follow-up (T1 relaxation time, 972 msec ± 26 vs 1006 msec ± 36 [P < .001]; T2 relaxation time, 54 msec ± 3 vs 58 msec ± 4 [P < .001]; T2 signal intensity ratio, 1.5 ± 0.3 vs 1.7 ± 0.3 [P = .03]). Left ventricular average systolic longitudinal strain had decreased at follow-up MRI (-23.4% ± 4.8 vs -19.6% ± 5.1, respectively; P = .005). New nonischemic LGE lesions were prevalent in two of 22 participants (9%). Compared with baseline, small pericardial effusions were more evident at follow-up (one of 22 participants [5%] vs 10 of 22 [45%]; P = .004). Conclusion In participants who received immune checkpoint inhibitor therapy for cancer treatment, follow-up cardiac MRI scans showed signs of systolic dysfunction and increased parameters of myocardial edema and inflammation. © RSNA, 2021 Online supplemental material is available for this article.

Sex-Specific Differences of the Inflammatory State in Experimental Autoimmune Myocarditis

Increasing evidence suggests male sex as a potential risk factor for a higher incidence of cardiac fibrosis, stronger cardiac inflammation, and dilated cardiomyopathy (DCM) in human myocarditis. Chronic activation of the immune response in myocarditis may trigger autoimmunity. The experimental autoimmune myocarditis (EAM) model has been well established for the study of autoimmune myocarditis, however the role of sex in this pathology has not been fully explored. In this study, we investigated sex differences in the inflammatory response in the EAM model. We analyzed the cardiac function, as well as the inflammatory stage and fibrosis formation in the heart of EAM male and female rats. 21 days after induction of EAM, male EAM rats showed a decreased ejection fraction, stroke volume and cardiac output, while females did not. A significantly elevated number of infiltrates was detected in myocardium in both sexes, indicating the activation of macrophages following EAM induction. The level of anti-inflammatory macrophages (CD68+ ArgI+) was only significantly increased in female hearts. The expression of Col3A1 and fibrosis formation were more prominent in males. Furthermore, prominent pro-inflammatory factors were increased only in male rats. These findings indicate sex-specific alterations in the inflammatory stage of EAM, with a pro-inflammatory phenotype appearing in males and an anti-inflammatory phenotype in females, which both significantly affect cardiac function in autoimmune myocarditis.

Myocardial T1 and T2 Mapping by Magnetic Resonance in Patients With Immune Checkpoint Inhibitor-Associated Myocarditis

BACKGROUND

Myocarditis is a potentially fatal complication of immune checkpoint inhibitor (ICI) therapy. Data on the utility of cardiovascular magnetic resonance (CMR) T1 and T2 mapping in ICI myocarditis are limited.

OBJECTIVES

This study sought to assess the value of CMR T1 and T2 mapping in patients with ICI myocarditis.

METHODS

In this retrospective study from an international registry of patients with ICI myocarditis, clinical and CMR findings (including T1 and T2 maps) were collected. Abnormal T1 and T2 were defined as 2 SD above site (vendor/field strength specific) reference values and a z-score was calculated for each patient. Major adverse cardiovascular events (MACE) were a composite of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block.

RESULTS

Of 136 patients with ICI myocarditis with a CMR, 86 (63%) had T1 maps and 79 (58%) also had T2 maps. Among the 86 patients (66.3 ± 13.1 years of age), 36 (41.9%) had a left ventricular ejection fraction <55%. Across all patients, mean z-scores for T1 and T2 values were 2.9 ± 1.9 (p < 0.001) and 2.2 ± 2.1 (p < 0.001), respectively. On Siemens 1.5-T scanner (n = 67), native T1 (1,079.0 ± 55.5 ms vs. 1,000.3 ± 22.1 ms; p < 0.001) and T2 (56.2 ± 4.9 ms vs. 49.8 ± 2.2 ms; p < 0.001) values were elevated compared with reference values. Abnormal T1 and T2 values were seen in 78% and 43% of the patients, respectively. Applying the modified Lake Louise Criteria, 95% met the nonischemic myocardial injury criteria and 53% met the myocardial edema criteria. Native T1 values had excellent discriminatory value for subsequent MACE, with an area under the curve of 0.91 (95% confidence interval: 0.84 to 0.98). Native T1 values (for every 1-unit increase in z-score, hazard ratio: 1.44; 95% confidence interval: 1.12 to 1.84; p = 0.004) but not T2 values were independently associated with subsequent MACE.

CONCLUSIONS

The use of T1 mapping and application of the modified Lake Louise Criteria provides important diagnostic value, and T1 mapping provides prognostic value in patients with ICI myocarditis.

Non-invasive assessment of early and acute myocarditis in a rat model using cardiac magnetic resonance tissue tracking analysis of myocardial strain

Background

Myocardial strain analysis can provide diagnostic and prognostic information for myocarditis. The aim of the present study was to assess early and acute myocarditis in a rat model using cardiac magnetic resonance tissue tracking (CMR-TT) for myocardial strain analysis. We compared the strain's findings with the histological and immunohistochemical results.

Methods

Experimental autoimmune myocarditis (EAM) was induced by footpad injections of porcine cardiac myosin. The rats were examined by 7.0T preclinical CMR at day 14 (n=15) and day 21 (n=16) after EAM induction and the two control groups (each n=15) were also examined at day 14 and day 21, respectively. Using CMR-TT, we found a global peak systolic radial strain (Err_SAX) and a circumferential strain (Ecc_SAX) from the short-axis cine views and a radial strain (Err_LAX) and a longitudinal strain (Ell_LAX) from the long-axis cine views, which were calculated by dedicated TT software. Subsequently, histological and immunohistochemical evaluations were performed.

Results

Ell_LAX significantly decreased in early myocarditis compared with the control (-23.40%±1.48% vs. -22.02%±0.81%, P<0.05). Err_SAX, Ecc_SAX, Err_LAX, and Ell_LAX values significantly reduced in acute myocarditis compared with the controls (Err_SAX: 34.27%±9.80% vs. 49.76%±4.97%, Ecc_SAX: -18.98%±3.69% vs. -24.13±1.23, Err_LAX: 33.21%±10.24% vs. 49.59%±5.69%, and Ell_LAX: -17.75%±3.58% vs. -23.39%±1.48%; P<0.001, respectively). The receiver operating characteristic curve showed that myocardial strain analysis had a good diagnostic performance in early and acute myocarditis. The pathological evaluation revealed that inflammatory lesions began to appear in early myocarditis and peaked in acute myocarditis.

Conclusions

The CMR-TT strain analysis allowed accurate and reliable evaluation of early and acute myocarditis in a rat model, and has the potential to serve as a diagnostic indicator for the assessment of myocardial dysfunction in myocarditis.

Estimation of total collagen volume: a T1 mapping versus histological comparison study in healthy Landrace pigs

Right ventricular biopsy represents the gold standard for the assessment of myocardial fibrosis and collagen content. This invasive technique, however, is accompanied by perioperative complications and poor reproducibility. Extracellular volume (ECV) measured through cardiovascular magnetic resonance (CMR) has emerged as a valid surrogate method to assess fibrosis non-invasively. Nonetheless, ECV provides an overestimation of collagen concentration since it also considers interstitial space. Our study aims to investigate the feasibility of estimating total collagen volume (TCV) through CMR by comparing it with the TCV measured at histology. Seven healthy Landrace pigs were acutely instrumented closed-chest and transported to the MRI facility for measurements. For each protocol, CMR imaging at 3T was acquired. MEDIS software was used to analyze T1 mapping and ECV for both the left ventricular myocardium (LV_myo) and left ventricular septum (LV_septum). ECV was then used to estimate TCV_CMR at LV_myo and LV_septum following previously published formulas. Tissues were prepared following an established protocol and stained with picrosirius red to analyze the TCV_histo in LV_myo and LV_septum. TCV measured at LV_myo and LV_septum with both histology (8 ± 5 ml and 7 ± 3 ml, respectively) and T1-Mapping (9 ± 5 ml and 8 ± 6 ml, respectively) did not show any regional differences. TCV_histo and TCV_CMR showed a good level of data agreement by Bland–Altman analysis. Estimation of TCV through CMR may be a promising way to non-invasively assess myocardial collagen content and may be useful to track disease progression or treatment response.

Accurate, precise, simultaneous myocardial T1 and T2 mapping using a radial sequence with inversion recovery and T2 preparation

We propose a simultaneous myocardial T1 and T2 mapping technique using a radial sequence with inversion recovery and T2 preparation, which achieves high accuracy and precision, with T1 and T2 reproducibility similar to the Modified Look-Locker Inversion recovery (MOLLI) sequence and the conventional bright blood T2 mapping technique, respectively. The sequence was developed by incorporating gold angle radial fast low angle shot (FLASH) readout combined with an inversion pulse and T2prep pulses. The extended Bloch equation simulation with slice profile correction (BLESSPC) algorithm was proposed to reconstruct T1 and T2 maps at the same time in a few seconds, while maintaining good T1 and T2 estimation accuracy. Accuracy and precision were compared among the proposed technique, MOLLI and conventional T2 mapping techniques using phantom studies, 10 healthy volunteers and three patients. In phantom studies, the proposed technique was more accurate than MOLLI (P < 0.05) while achieving similar precision (P = 0.3) in T1 estimation, and was more accurate (P < 0.05) and precise (P < 0.001) than conventional T2 mapping (two-parameter fitting) in T2 estimation. In vivo, the proposed technique achieved significantly higher T1 values (P < 0.001) and similar reproducibility (P = 0.3) compared with MOLLI, with significantly lower T2 values (P < 0.001) and similar reproducibility (P = 0.6) compared with the conventional T2 mapping technique. Thus, the proposed radial T1-T2 mapping technique allows for accurate, precise, simultaneous myocardial T1 and T2 mapping in an 11-heartbeat single breath-hold acquisition.

Journal of Cardiovascular Magnetic Resonance 2017

There were 106 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2017, including 92 original research papers, 3 reviews, 9 technical notes, and 1 Position paper, 1 erratum and 1 correction. The volume was similar to 2016 despite an increase in manuscript submissions to 405 and thus reflects a slight decrease in the acceptance rate to 26.7%. The quality of the submissions continues to be high. The 2017 JCMR Impact Factor (which is published in June 2018) was minimally lower at 5.46 (vs. 5.71 for 2016; as published in June 2017), which is the second highest impact factor ever recorded for JCMR. The 2017 impact factor means that an average, each JCMR paper that were published in 2015 and 2016 was cited 5.46 times in 2017.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in continuus fashion and in the chronologic order of acceptance, with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or theme, so that readers can view areas of interest in a single article in relation to each other and other contemporary JCMR articles. In this publication, the manuscripts are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought within the journal. In addition, I have elected to use this format to convey information regarding the editorial process to the readership.I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your very best, high quality manuscripts to JCMR for consideration. I thank our very dedicated Associate Editors, Guest Editors, and Reviewers for their efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the forefront journal of our field. And finally, I thank you for entrusting me with the editorship of the JCMR as I begin my 3rd year as your editor-in-chief. It has been a tremendous learning experience for me and the opportunity to review manuscripts that reflect the best in our field remains a great joy and highlight of my week!

Tissue characterization by T1 and T2 mapping cardiovascular magnetic resonance imaging to monitor myocardial inflammation in healing myocarditis

Aims

Monitoring disease activity in myocarditis is important for tailored therapeutic strategies. This study evaluated the ability of T1 and T2 mapping cardiovascular magnetic resonance (CMR) to monitor the course of myocardial inflammation in healing myocarditis.

Methods and Results

Forty-eight patients with strictly defined acute myocarditis underwent CMR at 1.5 T in the acute stage, at 3-months (n = 39), and at 12-months follow-up (FU) (n = 21). Normal values were obtained in a control group of 27 healthy subjects. The CMR protocol included standard ('Lake-Louise') sequences as well as T1 (modified Look-Locker inversion recovery sequence, MOLLI) and T2 (gradient- and spin-echo sequence, GraSE) mapping. T1, T2, and extracellular volume (ECV) maps were generated using an OsiriX plug-in. Native myocardial T1, T2, and ECV values were increased in the acute stage, but declined with healing of myocarditis. The performances of global native T1 and T2 to differentiate acute from healed myocarditis stages were significantly better compared with all other global CMR parameters with AUCs of 0.85 (95% CI, 0.76-0.94) and 0.83 (95% CI, 0.73-0.93). Furthermore, regional native T1 and T2 in myocarditis lesions provided AUCs of 0.97 (95% CI, 0.93-1.02) and 0.93 (95% CI, 0.85-1.01), which were significantly superior to any other global or regional CMR parameter.

Conclusion

Healing of myocarditis can be monitored by native myocardial T1 and T2 measurements without the need for contrast media. Both native myocardial T1 and T2 provide an excellent performance for assessing the stage of myocarditis by CMR.

Cardiac MR Characterization of left ventricular remodeling in a swine model of infarct followed by reperfusion

BACKGROUND

Myocardial infarction (MI) survivors are at risk of complications including heart failure and malignant arrhythmias.

PURPOSE

We undertook serial imaging of swine following MI with the aim of characterizing the longitudinal left ventricular (LV) remodeling in a translational model of ischemia-reperfusion-mediated MI.

ANIMAL MODEL

Eight Yorkshire swine underwent mid left anterior descending coronary artery balloon occlusion to create an ischemia-reperfusion experimental model of MI.

FIELD STRENGTH/SEQUENCES

1.5T Philips Achieva scanner. Serial cardiac MRI was performed at 16, 33, and 62 days post-MI, including cine imaging, native and postcontrast T1 , T2 and dark-blood late gadolinium enhanced (DB-LGE) scar imaging.

ASSESSMENT

Regions of interest were selected on the parametric maps to assess native T1 and T2 in the infarct and in remote tissue. Volume of enhanced tissue, nonenhanced tissue, and gray zone were assessed from DB-LGE imaging. Volumes, cardiac function, and strain were calculated from cine imaging.

STATISTICAL TESTS

Parameters estimated at more than two timepoints were compared with a one-way repeated measures analysis of variance. Parametric mapping data were analyzed using a generalized linear mixed model corrected for multiple observations. A result was considered statistically significant at P < 0.05.

RESULTS

All animals developed anteroseptal akinesia and hyperenhancement on DB-LGE with a central core of nonenhancing tissue. Mean hyperenhancement volume did not change during the observation period, while the central core contracted from 2.2 ± 1.8 ml at 16 days to 0.08 ± 0.19 ml at 62 days (P = 0.008). Native T1 of ischemic myocardium increased from 1173 ± 93 msec at 16 days to 1309 ± 97 msec at 62 days (P < 0.001). Mean radial and circumferential strain rate magnitude in remote myocardium increased with time from the infarct (P < 0.05).

DATE CONCLUSION

In this swine model of MI, serial quantitative cardiac MR exams allow characterization of LV remodeling and scar formation.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Blood T1* correction increases accuracy of extracellular volume measurements using 3T cardiovascular magnetic resonance: Comparison of T1 and T1* maps

The goals were to compare the differences between ECV_L (extracellular volume derived from myocardial T1 and blood T1), ECV_c (combination of myocardial T1 and blood T1*), and ECVnL (derived from myocardium T1* and blood T1*), and to explore the diagnostic accuracy of these factors for discriminating between controls and patients. The Modified Look-Locker Inversion Recovery sequence was performed in 42 subjects to generate both T1 and T1* maps. Native and post-contrast T1 values for myocardium and blood pool were obtained, and ECVL, ECVc, and ECVnL were then calculated. The global ECVc values were smaller than the ECVL values (0.006, 2.11%, p < 0.001) and larger than the ECVnL values (0.06, 21.6%, p < 0.001) in all participants. The ECVc led to a 4–6% increase in the AUC value and a 24–32% reduction in the sample size to differentiate between the controls and other patients when compared with the ECVL. Blood T1* correction can improve the precision of blood T1 values and can consequently increase the accuracy of the extracellular volume fraction measurement. The ECVc can be used to improve diagnostic accuracy and reduce the sample size required for a clinical study.

Review of Journal of Cardiovascular Magnetic Resonance (JCMR) 2015-2016 and transition of the JCMR office to Boston

The Journal of Cardiovascular Magnetic Resonance (JCMR) is the official publication of the Society for Cardiovascular Magnetic Resonance (SCMR). In 2016, the JCMR published 93 manuscripts, including 80 research papers, 6 reviews, 5 technical notes, 1 protocol, and 1 case report. The number of manuscripts published was similar to 2015 though with a 12% increase in manuscript submissions to an all-time high of 369. This reflects a decrease in the overall acceptance rate to <25% (excluding solicited reviews). The quality of submissions to JCMR continues to be high. The 2016 JCMR Impact Factor (which is published in June 2016 by Thomson Reuters) was steady at 5.601 (vs. 5.71 for 2015; as published in June 2016), which is the second highest impact factor ever recorded for JCMR. The 2016 impact factor means that the JCMR papers that were published in 2014 and 2015 were on-average cited 5.71 times in 2016.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in the order that they are accepted with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes with previously published JCMR papers to guide continuity of thought in the journal. In addition, I have elected to open this publication with information for the readership regarding the transition of the JCMR editorial office to the Beth Israel Deaconess Medical Center, Boston and the editorial process.Though there is an author publication charge (APC) associated with open-access to cover the publisher's expenses, this format provides a much wider distribution/availability of the author's work and greater manuscript citation. For SCMR members, there is a substantial discount in the APC. I hope that you will continue to send your high quality manuscripts to JCMR for consideration. Importantly, I also ask that you consider referencing recent JCMR publications in your submissions to the JCMR and elsewhere as these contribute to our impact factor. I also thank our dedicated Associate Editors, Guest Editors, and reviewers for their many efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the leading publication in our field.

Detection and Monitoring of Acute Myocarditis Applying Quantitative Cardiovascular Magnetic Resonance

BACKGROUND

Cardiovascular magnetic resonance based on the Lake Louise Criteria is used to make the diagnosis of acute myocarditis. Novel quantitative parametric mapping techniques promise to overcome some of its limitations. We aimed to evaluate quantitative cardiovascular magnetic resonance to detect and monitor acute myocarditis.

METHODS AND RESULTS

Eighteen patients with clinical diagnosis of acute myocarditis (25 years [23-38 years]; 78% males) were prospectively enrolled and repeatedly underwent cardiovascular magnetic resonance at 1.5 T seven days (5-10 days) after symptom onset (FU0), after 5 weeks (FU1), and after 6 months (FU2). Eighteen age- and sex-matched healthy subjects served as controls. Cardiovascular magnetic resonance included imaging of edema, hyperemia, necrosis, and fibrosis using semiquantitative T2-weighted spin echo, T2 mapping, and T1 mapping before and 3 and 10 minutes after gadobutrol administration. Extracellular volume for diffuse and late gadolinium enhancement for focal fibrosis were assessed. Compared with controls, patients had significantly higher global T2 times at FU0 (55.1 ms [53.3-57.2 ms] versus 50.2 ms [49.2-52.0 ms]; P<0.001) and at FU1 (52.0 ms [52.0-53.2 ms]; P=0.007), which normalized at FU2 (50.9 ms [49.6-53.3 ms]; P=0.323). Global native T1 times in patients were elevated acutely (1004 ms [988-1048 ms] versus 975 ms [957-1004 ms]; P=0.002) and remained elevated throughout the follow-up (FU1: 998 ms [990-1027 ms]; P=0.014; FU2: 1000 ms [972-1027 ms]; P=0.044). Global extracellular volume fraction was statistically not different between patients and controls (P=0.057). 77.8% (14/18) of patients had focal late gadolinium enhancement. T2 ratio was significantly elevated in patients with myocarditis at FU0 (2.2 [2.0-2.3] versus 1.6 [1.5-1.7]; P<0.001). The difference decreased during follow-up (FU1: 1.9 [1.7-1.9]; P=0.001 and FU2: 1.7 [1.7-1.8]; P=0.053). The diagnostic accuracy to discriminate between patients with acute myocarditis and healthy controls was 86% for T2>52 ms, 78% for native T1>981 ms, 74% for extracellular volume fraction >0.24, and 100% for T2 ratio >1.9.

CONCLUSIONS

Although both T2 and T1 mapping reliably detected acute myocarditis, only T2 mapping discriminated between acute and healed stages, underlining the incremental value of T2 mapping.

Cardiovascular magnetic resonance in systemic sclerosis: "Pearls and pitfalls"

Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular dysfunction and excessive fibrosis, involving internal organs including the heart. The estimated prevalence of cardiac involvement in SSc is high and remains subclinical until the late stages. It is either primary, related to myocardial inflammation and fibrosis, or secondary, due to pulmonary arterial hypertension (SSc-PAH) or systemic hypertension, in those patients with renal involvement. Cardiovascular magnetic resonance (CMR) is a useful tool for the early assessment of cardiac involvement in SSc. It is the gold standard technique to assess ventricular volumes,ejection fraction, and in particular is very useful to reliably and non-invasively detect myocardial inflammation, early perfusion defects, and myocardial fibrosis. However, the CMR evaluation in SSc may be problematic, because of cardiac and respiratory artefacts, commonly found in these patients. Therefore, a high level of expertise is necessary for both acquisition and interpretation of CMR images in SSc.