| Abstrakt: |
Background: T1ρ mapping is a new quantitative MRI technique in recent years. In order to use T1ρ mapping as a noncontrast method to assess myocardial fibrosis, it is necessary to establish a range of normal values. Purpose: To establish a potential normal range of cardiac T1ρ values in healthy adults and to explore the influence of slice location and gender on T1ρ values. Study Type: Prospective. Population: A total of 57 healthy volunteers without cardiovascular risk factors (age 26.7 ± 11.8 years; 29 males). Field Strength/Sequence: 1.5 T; modified Look‐Locker inversion recovery (MOLLI) (T1 mapping), multiecho gradient‐spin‐echo (GraSE) (T2 mapping) and T1ρ‐prepared steady‐state free precession (T1ρ mapping) sequences. Assessment: Basal, mid, and apical short‐axis left ventricular T1, T2, and T1ρ maps were acquired. T1ρ maps at spin‐locking frequencies of 5 and 400 Hz were subtracted to create myocardial fibrosis index (mFI) maps. Slice‐average and global average T1, T2, T1ρ, and mFI values were determined. Statistical Tests: Shapiro–Wilk test, Independent t‐test, ANOVA test, Pearson correlation coefficient (r). Significance: P value < 0.05. Results: The global average values of T1, T2, T1ρ, and mFI were 1053 ± 34 msec, 51.9 ± 2.3 msec, 47.9 ± 2.8 msec, and 4.4 ± 1.6 msec. T1ρ values showed a significant gradual increase from the basal slice to the apical slice of the heart (basal 46.5 ± 2.7 msec, mid 48.0 ± 2.9 msec, apical 49.2 ± 3.3 msec). The T1ρ and mFI values of females (49.7 ± 2.4 msec and 5.1 ± 1.2 msec, respectively) were significantly higher than those of males (46.2 ± 1.9 msec and 3.7 ± 1.7 msec, respectively). In addition, there was a moderate positive correlation between global T1ρ values and global T1 values (r = 0.44, P < 0.05) and a moderate positive correlation between global T1ρ values and global T2 values (r = 0.42, P < 0.05). Data Conclusion: In this study, the global T1ρ values of healthy adults' hearts were 47.9 ± 2.8 msec. This study found that gender and slice location of myocardium can affect the T1ρ values. Evidence Level: 4 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR] |
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