BackgroundT1 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.MethodsHealthy 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.ResultsIn 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.ConclusionWe 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12968-014-0069-x) contains supplementary material, which is available to authorized users.

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.

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.

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