Registration, segmentation and visualization of confocal microscopy images of arterial thrombus

Arterial thrombosis causes death or paralysis of an organ, as it migrates to and localizes in different parts of the body. Massive pulmonary emboli cause 50,000 deaths per year. The cause and origin of arterial thrombosis is not well understood nor objectively characterized. The object of this study was to investigate the microscopic structure of arterial thrombus to better understand this pathology. Confocal microscopy cross-sectional images of an embolized thrombus in the coronary artery were obtained. Adjacent pairs of sections were stained with two different stains, fibrin and CD61, to reveal mutually complementary information. The very thin adjacent slices were treated as one slice. Adjacent slices were registered by a combination of manual and automatic techniques using the Analyze software developed in the Biomedical Imaging Resource at Mayo. After smoothing the images with a median filter, the CD61 and fibrin stained section images were used to segment the tissues by multispectral classification. The image volume was classified into background, platelets and surrounding tissue, and thrombus. The segmented volume was then rendered for visualization and analysis of the structure of the thrombus in three dimensions. Preliminary results are promising. Such correlation of structural and histological information may be helpful in determining the origin of the thrombus.