MR extracellular volume mapping and non-contrast T1ρ mapping allow early detection of myocardial fibrosis in diabetic monkeys

Figures

• 

  Fig. 1. Results for animals with different degrees of diastolic dysfunction as compared with healthy controls. Differences in extracellular volume fraction (a), myocardial fibrosis index (b), T1ρ relaxation time (c), pre-contrast myocardial T1 (d), and post-contrast myocardial T1 (e) are compared between healthy control animals, monkeys with type 2 diabetes mellitus and mild diastolic dysfunction, and monkeys with type 2 diabetes mellitus and moderate diastolic dysfunction. Values in panels a–e are shown in box plots. One-way analysis of variance was used for comparing the differences among the three groups (this method was used for normally distributed data, including T1ρ, mFI, and pre-T1). For post hoc analysis, Fisher’s least significant difference test and the Student-Newman-Keuls test were used to compare the differences between every two groups. The Kruskal-Wallis H test was used to compare the differences among the three groups (this method was used for non-normally distributed data, including ECV and post-T1). The Dunn-Bonferroni test was used in post hoc analysis to compare the differences between every two groups. *p < 0.05

• 

  Fig. 2. Imaging examples of animals with different degrees of diastolic dysfunction and healthy control animals. The first row displays the echocardiographic mitral valve inflow (A1, B1, C1–1) and the septal mitral valve annular velocities (A1, B1, C1–2). The second row shows the T1ρ maps (A2, B2, C2–1) and the corresponding bull’s-eye plots (A2, B2, C2–2). The third row shows mFI maps (A3, B3, C3–1) and the corresponding bull’s-eye plots (A3, B3, C3–2). The fourth row shows the extracellular volume fraction maps (A4, B4, C4–1) and the corresponding bull’s-eye plots (A4, B4, C4–2). Differences in fibrosis content among the three groups of monkeys were clearly indicated by three fibrosis imaging markers with different image contrasts

• 

  Fig. 3. Correlation between extracellular volume fraction and the myocardial fibrosis index. A positive correlation was observed between the T1 mapping-derived extracellular volume fraction and the T1ρ mapping-derived myocardial fibrosis index

• 

  Fig. 4. Correlation between imaging markers of diffuse myocardial fibrosis and diastolic function. a A negative correlation was observed between E’ and the myocardial fibrosis index. b A negative correlation was observed between E’ and the extracellular volume fraction. c A negative correlation was found between the peak diastolic longitudinal strain rate and the myocardial fibrosis index. d A negative correlation was found between the peak diastolic longitudinal strain rate and the extracellular volume fraction

• 

  Fig. 5. Masson staining and corresponding cardiac magnetic resonance images from one monkey with moderate diastolic dysfunction. Masson staining is shown under high-power magnification (× 100). (a) Collagen fibers were stained with aniline blue, and cardiomyocytes were stained red. The blue rectangles in the T1ρ map (b), the myocardial fibrosis index map (c), and the extracellular volume fraction map (d) indicate the approximate areas form which the histopathological slides were taken. The values in each map indicate the mean T1ρ, myocardial fibrosis index, and extracellular volume fraction values measured in the blue rectangles