A computer-implemented method for modelling blood vessels, the method comprising the steps of: - obtaining medical imaging data of the blood vessels; - generating a three-dimensional personalized model of the blood vessels, based on the medical imaging data; - generating a three-dimensional reference model of the blood vessels that reflects a state of healthy blood vessels that lack lesions, based on the medical imaging data or based on numerical reconstruction of the personalized model; characterized by: - performing a numerical simulation of blood flow for the same physical and boundary conditions in the personalized model and in the reference model, the simulation comprising determining conditions of blood flow at an inlet to the blood vessels model and calculating blood flow energy for the inlet and all outlets of the blood vessels model; ∘comparing the blood flow energy E f measured for the personalized model and for the reference model, wherein the blood flow energy E f is defined as the product of the total pressure and the mass flow rate Ef = 1 2 U 2 + P ρ Q = P total Q wherein 1⁄2 U 2 is a dynamic pressure, P/ ρ is a static pressure, P total is the total pressure and Q is the flow rate through the surface perpendicular to the axis of the vessel; - determining flow energy change indexes ΔEf of the blood flow in branches of the model based on the blood flow energy in the personalized model and in the reference model, wherein the energy change index ΔEf is calculated as: Δ Ef = Ef sten − Ef 0 wherein Ef sten is the flow energy in the branch of the personalized model and Ef 0 is the flow energy in the same branch of the reference model. - obtaining medical imaging data of the blood vessels; - generating a three-dimensional personalized model of the blood vessels, based on the medical imaging data; - generating a three-dimensional reference model of the blood vessels that reflects a state of healthy blood vessels that lack lesions, based on the medical imaging data or based on numerical reconstruction of the personalized model; - performing a numerical simulation of blood flow for the same physical and boundary conditions in the personalized model and in the reference model, the simulation comprising determining conditions of blood flow at an inlet to the blood vessels model and calculating blood flow energy for the inlet and all outlets of the blood vessels model; ∘comparing the blood flow energy E f measured for the personalized model and for the reference model, wherein the blood flow energy E f is defined as the product of the total pressure and the mass flow rate Ef = 1 2 U 2 + P ρ Q = P total Q wherein 1⁄2 U 2 is a dynamic pressure, P/ ρ is a static pressure, P total is the total pressure and Q is the flow rate through the surface perpendicular to the axis of the vessel; ∘comparing the blood flow energy E f measured for the personalized model and for the reference model, wherein the blood flow energy E f is defined as the product of the total pressure and the mass flow rate Ef = 1 2 U 2 + P ρ Q = P total Q wherein 1⁄2 U 2 is a dynamic pressure, P/ ρ is a static pressure, P total is the total pressure and Q is the flow rate through the surface perpendicular to the axis of the vessel; - determining flow energy change indexes ΔEf of the blood flow in branches of the model based on the blood flow energy in the personalized model and in the reference model, wherein the energy change index ΔEf is calculated as: Δ Ef = Ef sten − Ef 0 wherein Ef sten is the flow energy in the branch of the personalized model and Ef 0 is the flow energy in the same branch of the reference model.