Myocardial T1 Values at 1.5 T: Normal Values for General Electric Scanners and Sex‐Related Differences

Abstract

Background No data are available about normal ranges for native T1 in human myocardium using General Electric (GE) scanners. Purpose To establish normal ranges for myocardial T1 values and evaluate regional variability and the influence of physiological factors. Study type Prospective. Subjects One hundred healthy volunteers with normal electrocardiogram, no cardiovascular/systemic diseases, or risk factors (age range: 20–70 years; 50 females). Field Strength/Sequence 1.5 T/Steady‐state free precession cine and a modified Look–Locker inversion recovery sequence in diastole (also in systole for 61 volunteers). Assessment Image analysis was performed by operators with >10 years experience in cardiac MR using commercially available software. T1 values were calculated for 16 myocardial segments, and the global value was the mean. Segments were grouped according to circumferential region (anterior, septal, inferior, and lateral) and to level (basal, medial, apical). Twenty images were analyzed twice by the same operator and by a different operator to assess reproducibility. Statistical Tests Independent‐samples t‐test or Mann–Whitney test; paired sample t‐test or Wilcoxon signed‐rank test; one‐way repeated measures ANOVA or Friedman tests; Pearson's or Spearman's correlation. Reproducibility evaluated using coefficient of variability (CoV). Results Due to artifacts and/or partial‐volume effects, 45/1600 (2.8%) segments were excluded. A good intra‐ and inter‐operator reproducibility was detected (CoV < 5%). There were significant differences in segmental T1 values (P < 0.05). A significant circumferential variability was present (P < 0.05): the mean native T1 value over the lateral region was significantly lower than in the other three regions. An increasing gradient from basal to apical slices was detected (P < 0.05). Segmental and global T1 values were not associated with age (range P = 0.052–0.911) but were significantly lower in males than in females (global: 993 ± 32 vs. 1037 ± 27 ms; P < 0.05) and significantly correlated with heart rate (range R for segmental values = 0.247–0.920; P < 0.05). Almost all segmental T1 values were inversely correlated with wall thickness (R from −0.233 to −0.514; P < 0.05). Systolic T1 values were significantly lower than diastolic values in basal anteroseptal segment, in all medial segments except the inferior one, and in all apical segments (P < 0.05). Data Conclusion Myocardial T1 values differ among myocardial regions, are influenced by sex, heart rate, and wall thickness and vary according to the cardiac cycle in healthy adults. Level of Evidence 2 Technical Efficacy Stage 2

Cardiovascular magnetic resonance native T1 mapping in Anderson-Fabry disease: a systematic review and meta-analysis

“…Meta-regression analysis showed that heterogeneity in native T1 values among AFD patients could be explained by two major variables, gender and LVH. The cause of higher myocardial native T1 values in pre-menopausal women is not completely defined and it relies on different factors, at least in part explained by thinner myocardial walls with a predisposition to partial-volume effect, lower hematocrit values, and different myocardial characteristics due to the hormone status [ 33 ]. In addition, AFD genetic inheritance is recessive X-linked and therefore in hemizygous men, enzyme α-galactosidase A activity is completely absent, while in heterozygous women it is guaranteed by the presence of wild-type gene on the other allele [ 34 ].…”

Cardiac magnetic resonance findings in neuronal ceroid lipofuscinosis: A case report

“…Before the administration of the contrast agent, a sequence MOLLI SSFP for native T1 mapping was performed. Native T1 values were calculated by dedicated postprocessing software (Circle Cardiovascular Imaging, Alberta, Canada) and significantly shortened than normal values of the Laboratory were obtained (global T1 of LV was 885 ms, normal value ≥ 928 ms) ( Figure 3 ) ( 16 ). No areas of LGE (defined as hyperintense areas after administration of gadoteric acid ≥ 6 standard deviations than a region of interest in the background) were detected in the myocardium, covering the entire left ventricle from the mitral valve plane to the apex ( Figure 4 ).…”

Editorial for "Myocardial T1 Values at 1.5 T: Normal Values for General Electric Scanners and Sex‐Related Differences"

“…In this JMRI issue, the work by Meloni et al contributes to this body of knowledge by providing native T1 myocardium values for the GE 1.5 T scanner platform. 4 A more important contribution of Meloni et al's work is the assessment of physiological variation of native T1 values. They comprehensively investigated the segmental variation, gender-based variation, and cardiac phase-based variation in native myocardial T1 values.…”

“…Acknowledging the different sources of variability, imaging sites are encouraged to measure their site‐specific native T1 reference values using the sequence, scanner platform, postprocessing tools, and population for their intended clinical use. In this JMRI issue, the work by Meloni et al contributes to this body of knowledge by providing native T1 myocardium values for the GE 1.5 T scanner platform 4 …”