Evaluation of microvascular permeability of skeletal muscle and texture analysis based on DCE-MRI in alloxan-induced diabetic rabbits.

OBJECTIVES

To estimate the microvascular permeability and perfusion of skeletal muscle by using quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and explore the feasibility of using texture analysis (TA) to evaluate subtle structural changes of diabetic muscles.

METHODS

Twenty-four rabbits were randomly divided into diabetic (n = 14) and control (n = 10) groups, and underwent axial DCE-MRI of the multifidus muscle (0, 4, 8, 12, and 16 weeks after alloxan injection). The pharmacokinetic model was used to calculate the permeability parameters; texture parameters were extracted from volume transfer constant (K) map. The two-sample t test/Mann-Whitney U test, repeated measures analysis of variance/Friedman test, and Pearson correlations were used for data analysis.

RESULTS

In the diabetic group, K and rate constant (K) increased significantly at week 8 and then showed a decreasing trend. Extravascular extracellular space volume fraction (V) increased and plasma volume fraction (V) decreased significantly from the 8th week. Skewness began to decrease at the 4th week. Median K and entropy increased significantly, while inverse difference moment decreased from the 8th week. Energy decreased while contrast increased only at week 8. Muscle fibre cross-sectional area was negatively correlated with V. The capillary-to-fibre ratio was positively correlated with V (p < 0.05, all).

CONCLUSIONS

Quantitative DCE-MRI can be used to evaluate microvascular permeability and perfusion in diabetic skeletal muscle at an early stage; TA based on K map can identify microarchitectural modifications in diabetic muscles.

KEY POINTS

• Four quantitative parameters of DCE-MRI can be used to evaluate microvascular permeability and perfusion of skeletal muscle in diabetic models at early stages. • Texture analysis based on K map can identify subtle structural changes in diabetic muscles.