Method for determining the volume of epicardial fat of a heart, comprising: - acquiring a plurality of volumetric image data representing the heart; - morphologically characterizing a volume of interest represented by said volumetric image data, including identifying a predetermined number of reference contours (P i) of the heart; - estimating the epicardial surface, ∑, according to a three-dimensional model based on a series expansion of vectorial spherical harmonic functions from said reference contours (P i); - determining the volume of epicardial fat based on the voxels which are located inside the estimated epicardial surface, ∑, and which have a grey level within a predetermined range, characteristic of fatty tissue, and - estimating the epicardial surface includes: - expressing the surface as a series of vector spherical harmonic functions in parametric form, as x φ θ = ∑ n = 0 N ∑ m = 0 n a mn ⁢ cos mφ + b mn ⁢ sin mφ ⁢ P mn cos θ where a mn, b mn are the vector coefficients of the series, P mn (t) are the associated Legendre polynomials of degree n and order m, the number N is the order of the surface, and φ,θ are the spherical coordinates with respect to the centroid of the reference contours; characterised in that it comprises determining the coefficients of the series expansion of vector spherical harmonic functions by minimizing a cost functional C a mn b mn = α ⁢ P a mn b mn + β ⁢ G a mn b mn + γε a mn b mn + δ ⁢ S a mn b mn wherein - is a functional representing an error of approximation of the epicardial surface (∑) by the reference contours (P i); - G' is a functional representing the presence within the surface of grey levels outside said predetermined range of grey levels of the fatty tissue; - ε is a functional representing the gradients of grey levels at the interface of the epicardial surface; - S is a functional representing the regularity of the surface, and the coefficients α, β, γ, δ are chosen with the values α, δ = 1 and β, γ = 10 -2. - acquiring a plurality of volumetric image data representing the heart; - morphologically characterizing a volume of interest represented by said volumetric image data, including identifying a predetermined number of reference contours (P i) of the heart; - estimating the epicardial surface, ∑, according to a three-dimensional model based on a series expansion of vectorial spherical harmonic functions from said reference contours (P i); - determining the volume of epicardial fat based on the voxels which are located inside the estimated epicardial surface, ∑, and which have a grey level within a predetermined range, characteristic of fatty tissue, and - estimating the epicardial surface includes: - expressing the surface as a series of vector spherical harmonic functions in parametric form, as x φ θ = ∑ n = 0 N ∑ m = 0 n a mn ⁢ cos mφ + b mn ⁢ sin mφ ⁢ P mn cos θ where a mn, b mn are the vector coefficients of the series, P mn (t) are the associated Legendre polynomials of degree n and order m, the number N is the order of the surface, and φ,θ are the spherical coordinates with respect to the centroid of the reference contours; characterised in that it comprises determining the coefficients of the series expansion of vector spherical harmonic functions by minimizing a cost functional C a mn b mn = α ⁢ P a mn b mn + β ⁢ G a mn b mn + γε a mn b mn + δ ⁢ S a mn b mn wherein - is a functional representing an error of approximation of the epicardial surface (∑) by the reference contours (P i); - G' is a functional representing the presence within the surface of grey levels outside said predetermined range of grey levels of the fatty tissue; - ε is a functional representing the gradients of grey levels at the interface of the epicardial surface; - S is a functional representing the regularity of the surface, and the coefficients α, β, γ, δ are chosen with the values α, δ = 1 and β, γ = 10 -2.