METHOD FOR ASSESSING FACTORS OF RISK OF CEREBRAL ANEURYSM RUPTURE AFTER INSTALLING A FLOW-DIVERTING STENT Russian patent published in 2022 - IPC A61B6/03 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to diagnostics. A medical image containing information about blood vessels is obtained. The geometry of the blood vessel of interest is extracted from the medical image. Information about the commercial model of the installed flow-diverting stent is obtained by manual selection. Additional data on the characteristics of blood flow in the affected vessel are obtained. Virtual models of the selected flow-diverting stent inside the geometry of the blood vessel are created, wherein the flow-diverting stent is modelled in the form of a tube with a porous surface, blood flow through the flow-diverting stent is evaluated, the predicted blood flow is a characteristic by which the effectiveness of installation of the flow-diverting stent is assessed. Threshold levels of permissible differentials of longitudinal and transverse displacements of the aneurysm neck under the flow-diverting stent relative to the similar displacements of the blood vessel wall under the flow-diverting stent of a healthy wall of the blood vessel, threshold levels for differentials of blood flow velocity and blood pressure in similar spatial positions are determined and introduced. A set of three-dimensional medical images of intravascular optical coherence tomography is therein used to extract the geometry of the blood vessel of interest, wherein the scanning of the walls of the affected blood vessel is synchronised with the collection of data on the blood pressure and blood flow velocity. A first and a second medical images corresponding to the moments of systole and diastole are then selected from the set of three-dimensional images of intravascular optical coherence tomography, the first and the second medical images are compared by control points. The found vector values of absolute displacements are decomposed along the coordinate axes into longitudinal and transverse components, the longitudinal and transverse displacements of structures of the aneurysm neck are compared with the longitudinal and transverse displacements of a healthy wall of the blood vessel on the side opposing the aneurysm. The modules of blood flow velocity, as well as systolic and diastolic pressure for the same spatial positions and time points corresponding to the first and second medical images are compared in pairs. Risk factors for postoperative complications are considered if one of the following parameters: the differential of longitudinal displacement of the aneurysm neck, the differential of transverse displacement of the aneurysm neck, the differential of blood flow velocity, or the differential of blood pressure, exceeded the predetermined threshold level.

EFFECT: method allows for an increase in the speed of assessment of factors of stroke risk as a result of occlusion of the internal lumen of the flow-diverting stent, or rupture of the aneurysm after installing the flow-diverting stent, due to the analysis of absolute displacements in the wall of the affected blood vessel, as well as the differential of pressure and velocity of blood flow for multiple sections of the internal lumen of the flow-diverting stent.

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