Cardiac MRI in common marmosets revealing age-dependency of cardiac function

Figures

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  Figure 1. Achieved image quality and navigator signal. (a) Only images with at least good quality (e.g. animal A, score = 5) were selected for further quantification whereas images with low quality (scoring < 3) were excluded from further quantification (animal B–E). Respiratory artifacts (B), no visible ventricular contraction (C,D), low blood-myocardium contrast (D,E) and fuzziness (D) are the main image artifacts which significantly reduced the diagnostic value of the images. All images are in the diastolic phase. (b) Time course of the navigator signal of the excluded animals (B–E) compared to a high-score animal (A): Signal changes due to cardiovascular movement are visible although to different extent. (c) Fourier analysis of the navigator signal: the sharp peak at 35 bpm represents the respiration whereas the widespread peak accumulation around 200–250 bpm corresponds to the cardiac rate.

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  Figure 2. Diastole and Systole. Diastolic and systolic images of the heart of two marmosets (Animal F and G) with the highest quality score of 5. In particular, papillary muscles and trabecularization were well resolved.

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  Figure 3. Age dependency of physiological parameter. (a–c) The weight of the hearts correlates with the body weight of the animals, the left ventricular myocardial volume and the total muscle volume (p < 0.01 for all). Body weight (d), heat rate (e) and post-mortem weight of the heart (f) of the marmosets were almost equally distributed between the 3 age groups (n = 10/9/10). The central line of the box plot indicates the median, the edges are the 25th and 75th percentile and the outliers are visualized by the ‘+’ symbol.

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  Figure 4. Age dependency of ventricle myocardial volume. The right and total volume of the ventricle muscle were decreased with age (a,b). This became even more evident when normalizing the volumes to the post-mortem weight of the heart (c) and involved in particular the right ventricle (a,c). This volume lost was accompanied with an increase in the apparent myocardial tissue density of the myocardium (d). The data were compared using one-way ANOVA, followed by a t-test (*P < 0.05, **P < 0.01, ***P < 0.001). The central line of the box plot indicates the median, the edges are the 25th and 75th percentile and the outliers are visualized by the ‘+’ symbol. n = 10/9/10 for all graphs.

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  Figure 5. Age dependency of cardiac function. EDV, ESV and SV showed for both the left and right ventricle a trend to lower values in older marmosets. However, only RV-EDV and RV-ESV revealed a significant age effect. When correcting for the weight of the heart the LV-EDV showed a significant reduction with age. The SV relative to the heart weight also revealed a tendency to lower values in old marmosets but missed the level of significance for both left and right ventricle. The EF was almost equal within the age group. The data were compared using one-way ANOVA, followed by a t-test (*P < 0.05, **P < 0.01, ***P < 0.001). The central line of the box plot indicates the median, the edges are the 25th and 75th percentile and the outliers are visualized by the ‘+’ symbol. n = 10/9/10 for all graphs.