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.

Objectives Quantification of myocardial deformation by feature tracking is of growing interest in cardiovascular magnetic resonance. It allows the assessment of regional myocardial function based on cine images. However, image acquisition, post-processing, and interpretation are not standardized. We aimed to assess the influence of segmentation procedure such as slice selection and different types of analysis software on values and quantification of myocardial strain in healthy adults. Methods Healthy volunteers were retrospectively analyzed. Post-processing was performed using CVI42 and TomTec. Longitudinal and radialLong axis (LAX) strain were quantified using 4-chamber-view, 3-chamber-view, and 2-chamber-view. Circumferential and radialShort axis (SAX) strain were assessed in basal, midventricular, and apical short-axis views and using full coverage. Global and segmental strain values were compared to each other regarding their post-processing approach and analysis software package. Results We screened healthy volunteers studied at 1.5 or 3.0 T and included 67 (age 44.3 ± 16.3 years, 31 females). Circumferential and radialSAX strain values were different between a full coverage approach vs. three short slices (− 17.6 ± 1.8% vs. − 19.2 ± 2.3% and 29.1 ± 4.8% vs. 34.6 ± 7.1%). Different analysis software calculated significantly different strain values. Within the same vendor, different field strengths (− 17.0 ± 2.1% at 1.5 T vs. − 17.0 ± 1.7% at 3 T, p = 0.845) did not influence the calculated global longitudinal strain (GLS), and were similar in gender (− 17.4 ± 2.0% in females vs. − 16.6 ± 1.8% in males, p = 0.098). Circumferential and radial strain were different in females and males (circumferential strain − 18.2 ± 1.7% vs. − 17.1 ± 1.8%, p = 0.029 and radial strain 30.7 ± 4.7% vs. 27.8 ± 4.6%, p = 0.047). Conclusions Myocardial deformation assessed by feature tracking depends on segmentation procedure and type of analysis software. CircumferentialSAX and radialSAX depend on the number of slices used for feature tracking analysis. As known from other imaging modalities, GLS seems to be the most stable parameter. During follow-up studies, standardized conditions should be warranted. Trial registration Retrospectively registered Key Points • Myocardial deformation assessed by feature tracking depends on the segmentation procedure. • Global myocardial strain values differ significantly among vendors. • Standardization in post-processing using CMR feature tracking is essential.

BackgroundWe hypothesized that the contrast medium gadobutrol is not inferior compared to Gd-DTPA in identifying and quantifying ischemic late gadolinium enhancement (LGE), even by using a lower dose.MethodsWe prospectively enrolled 30 patients with chronic myocardial infarction as visualized by LGE during clinical routine scan at 1.5 T with 0.20 mmol/kg Gd-DTPA. Participants were randomized to either 0.15 mmol/kg gadobutrol (group A) or 0.10 mmol/kg gadobutrol (group B). CMR protocol was identical in both exams.LGE was quantified using a semiautomatic approach. Signal intensities of scar, remote myocardium, blood and air were measured. Signal to noise (SNR) and contrast to noise ratios (CNR) were calculated.ResultsSignal intensities were not different between Gd-DTPA and gadobutrol in group A, whereas significant differences were detected in group B. SNR of injured myocardium (53.5+/−21.4 vs. 30.1+/−10.4, p = 0.0001) and CNR between injured and remote myocardium (50.3+/−20.3 vs. 27.3+/−9.3, p < 0.0001) were lower in gadobutrol. Infarct size was lower in both gadobutrol groups compared to Gd-DTPA (group A: 16.8+/−10.2 g vs. 12.8+/−6.8 g, p = 0.03; group B: 18.6+/−12.0 g vs. 14.0+/−9.9 g, p = 0.0016).ConclusionsTaking application of 0.2 mmol/kg Gd-DTPA as the reference, the delineation of infarct scar was similar with 0.15 mmol/kg gadobutrol, whereas the use 0.10 mmol/kg gadobutrol led to reduced tissue contrast.Trial registrationThe study had been registered under EudraCT Number: 2010-020775-22. Registration date: 2010.08.10