Automatic analysis of retinal and carothid images: correlation between retinal microcirculation and cerebro-vascular macrocirculation

The cardio and cerebrovascular diseases are established risk factors for dementia and cognitive impairment. Also, brain injuries are a very important aspect in the field of cardiovascular risk factors, mainly hypertension (HTA). Currently, the pathophysiology of the vessel in hypertensive patients can be studied through noninvasive methods that are most useful from the standpoint of population, as ultrasonography of the carotid arteries, which measures the thickness of the intima-media thickness (IMT). The IMT is a measure of subclinical macrovasculature injury and is considered to be closely associated with the detriment of cognitive brain functions. Its correct measurement is therefore a key aspect in determining possible risk factors for diseases such as hypertension.
Moreover, the alterations in retinal vessels generally reflect similar changes in the network cerebrovascular pathologies associated with high prevalence in society, such as hypertension and diabetes. In particular, the alteration of the ratio between arteries and veins (arterio venous index) and the appearance of small lesions in the eye fundus, the microaneurysms. In the latter case, moreover, the monitoring of the lesions is an important factor in establishing the risk of the patient.

Objectives

The main objective of the project is the development of methodologies based on artificial vision and image processing techniques to detect and automatically measure all variables associated first to the retinal microcirculation and, secondly, to the cerebral circulation. In more detail:

  • Automatic calculation of the index-arterio-venous: Includes automatic and accurate classification of retinal vessels in artery or vein and subsequent automatic selection of the measuring position of vascular caliber for index calculation.
  • Detection and monitoring of microaneurysms and neovascularization over time: First, address the automatic detection of microaneurysms (red lesions) and vascular structure. Next neovascularization and aneurysms will be tracked using image retina registration techniques already developed and finally a methodology for analysis of temporal evolution of these structures will be developed.
  • Automatic measurement of intima-media thickness in carotid images: Includes the development of a methodology for the segmentation of structures from carotid Doppler images, a field in which researchers from the University of Porto have extensive experience, and the development of adjustment and measurement techniques between control nodes deformable model to perform such measurement.
  • Finally, validation of the techniques developed with real patients and their incorporation into the clinical trial project object correlation Relationship between retinal microcirculation and cerebral microcirculation 10CSA918054PR.