T1 and T2 Mapping in Recognition of Early Cardiac Involvement in Systemic Sarcoidosis.

Purpose To determine whether quantitative tissue characterization with T1 and T2 mapping supports recognition of myocardial involvement in patients with systemic sarcoidosis. Materials and Methods Fifty-three consecutive patients with a biopsy-proven extracardiac diagnosis of systemic sarcoidosis (21 men; median age, 45 years; interquartile range, 22 years) and 36 normotensive previously healthy control subjects (14 men; median age, 43 years; interquartile range, 18 years) underwent cardiovascular magnetic resonance imaging, which was performed to assess cardiac function and late gadolinium enhancement, and T1 and T2 mapping. A follow-up substudy was performed in 40 patients (mean follow-up interval, 144 days ± 35 [standard deviation]); of these 40 patients, 18 underwent anti-inflammatory treatment for systemic symptoms. Binary logistic regression and receiver operating characteristic curve analyses were used to assess discrimination between health and disease; Wilcoxon signed rank test was used to assess the effect of treatment. Results When compared with control subjects, patients had higher ventricular volume, higher myocardial native T1 and T2, and lower longitudinal strain and ejection fraction (P < .05 for all). Myocardial native T1 and T2 had higher discriminatory accuracy (area under the receiver operating characteristic curve [AUC]: 0.96 and 0.89, respectively) for separation between control subjects and patients when compared with the standard diagnostic criteria (AUC < 0.67). Native T1 was the independent discriminator between health and disease (specificity, 90%; sensitivity, 96%; accuracy, 94%). There was a significant reduction of native T1 and T2 in the patients who underwent treatment (z score: -3.72 and -2.88; P < .01) but not in the patients who did not (z score, -1.42 and -1.38; P > .15). Conclusion Quantitative myocardial tissue characterization with T1 and T2 mapping may enable noninvasive recognition of cardiac involvement and activity of myocardial inflammation in patients with systemic sarcoidosis. Future studies will be performed to confirm their role in risk stratification and guidance of clinical management. © RSNA, 2017 Online supplemental material is available for this article.

Reference values for healthy human myocardium using a T1 mapping methodology: results from the International T1 Multicenter cardiovascular magnetic resonance study.

BACKGROUND: T1 mapping is a robust and highly reproducible application to quantify myocardial relaxation of longitudinal magnetisation. Available T1 mapping methods are presently site and vendor specific, with variable accuracy and precision of T1 values between the systems and sequences. We assessed the transferability of a T1 mapping method and determined the reference values of healthy human myocardium in a multicenter setting. METHODS: Healthy subjects (n=102; mean age 41 years (range 17-83), male, n=53 (52%)), with no previous medical history, and normotensive low risk subjects (n=113) referred for clinical cardiovascular magnetic resonance (CMR) were examined. Further inclusion criteria for all were absence of regular medication and subsequently normal findings of routine CMR. All subjects underwent T1 mapping using a uniform imaging set-up (modified Look- Locker inversion recovery, MOLLI, using scheme 3(3)3(3)5)) on 1.5 Tesla (T) and 3 T Philips scanners. Native T1-maps were acquired in a single midventricular short axis slice and repeated 20 minutes following gadobutrol. Reference values were obtained for native T1 and gadolinium-based partition coefficients, λ and extracellular volume fraction (ECV) in a core lab using standardized postprocessing. RESULTS: In healthy controls, mean native T1 values were 950±21 msec at 1.5 T and 1052±23 at 3 T. λ and ECV values were 0.44±0.06 and 0.25±0.04 at 1.5 T, and 0.44±0.07 and 0.26±0.04 at 3 T, respectively. There were no significant differences between healthy controls and low risk subjects in routine CMR parameters and T1 values. The entire cohort showed no correlation between age, gender and native T1. Cross-center comparisons of mean values showed no significant difference for any of the T1 indices at any field strength. There were considerable regional differences in segmental T1 values. λ and ECV were found to be dose dependent. There was excellent inter- and intraobserver reproducibility for measurement of native septal T1. CONCLUSION: We show transferability for a unifying T1 mapping methodology in a multicenter setting. We provide reference ranges for T1 values in healthy human myocardium, which can be applied across participating sites.

Native T1 and T2 mapping by CMR in lupus myocarditis: Disease recognition and response to treatment.

BACKGROUND: Lupus myocarditis is likely more common than recognized clinically due to non-specific symptoms and lack of reliable non-invasive diagnostic tests. We investigated the role of native T1 and T2 in recognition of active myocardial inflammatory involvement in patients with systemic lupus erythematous (SLE). METHODS: 76 patients with clinically suspected lupus myocarditis (14 males, age: 44±16years) underwent quantitative tissue characterization with native T1 and T2 mapping. Normotensive healthy subjects taking no medication served as controls (n=46). Follow-up CMR studies were performed in a total of 35 subjects of which 14 patients received intensified anti-inflammatory treatment, as guided by SLE disease activity. RESULTS: Compared to controls SLE patients had higher inflammatory markers, LV mass, native T1 and T2 values, and reduced longitudinal strain (p<0.01). In patients with a positive troponin test (n=36; 46%), native T1 and T2 were significantly higher (p<0.01) with otherwise similar proportions of diffuse perimyocardial LGE (33%) and pericardial effusion (32%). Sixty-nine patients (83%) had an abnormal native T1, whereas 51 (71%) met diagnostic criteria for acute myocarditis. Follow-up CMRs revealed significantly greater reduction in native T1 and T2 values in patients with intensified anti-inflammatory treatment (p<0.001) with the greatest change observed within the first follow-up period and plateauing thereafter. Native T1 and T2 were significant predictors of treatment response. CONCLUSIONS: Native T1 and T2 mapping support recognition of lupus myocarditis and reflect the response to anti-inflammatory treatment. Native T1 and T2 mapping may support an effective, noninvasive, radiation- and gadolinium contrast-free screening method for lupus myocarditis.

Native T1 in discrimination of acute and convalescent stages in patients with clinical diagnosis of myocarditis: a proposed diagnostic algorithm using CMR.

OBJECTIVES: This study investigated whether T1 mapping by cardiac magnetic resonance (CMR) reflects the clinical evolution of disease in myocarditis and supports its diagnosis independently of the disease stages. BACKGROUND: Acute viral myocarditis is characterized by a range of intracellular changes due to viral replication and extracellular spill of debris within days of viral infection. Convalescence may be characterized by a chronic low-grade inflammation leading to ventricular remodelling, but also a complete resolution of myocardial changes. METHODS: Patients with clinical diagnosis of viral myocarditis (N = 165) underwent routine clinical CMR protocol (1.5- and 3.0-T) for assessment of cardiac function and structure, and tissue characterization with T2-weighted imaging and late gadolinium enhancement. T1 mapping was obtained in a mid-ventricular short-axis slice before and >20 min after administration of 0.2 mmol/kg of gadobutrol. RESULTS: Compared with control subjects (n = 40), T1 indexes were increased in patients with myocarditis. Patients with acute symptoms (n = 61) had higher values of T1 indexes compared with patients in clinical convalescence (n = 67). Native T1 is an independent discriminator between health and disease, as well as a discriminator between acute and convalescent stage of the disease. Native T1- was superior to T2-weighted imaging and late gadolinium enhancement with high diagnostic accuracy and positive and negative predictive values. Using pre-defined cutoff values for normal ranges, we demonstrated that acute myocarditis can be independently identified by native T1 of >5 SD above the mean of normal range, whereas convalescence is best defined by either abnormal native T1 (>2 SD) or presence of late gadolinium enhancement. We prospectively tested a new diagnostic algorithm in an independent dataset of patients with clinical diagnosis of myocarditis and achieved similar diagnostic performance. CONCLUSIONS: The new diagnostic algorithm using native T1 can reliably discriminate between health and disease and determine the clinical disease stage in patients with a clinical diagnosis of myocarditis.