Analysis of morphological and hemodynamical indexes in abdominal aortic aneurysms as preliminary indicators of intraluminal thrombus deposition.

In this paper, we study the correlation between the wall shear stress, a hemodynamical index derived from numerical simulations, and an new index MFA-ILT for the characterization of intraluminal thrombus (ILT) in the presence of abdominal aortic aneurysms. Based on the processing of medical images, we define our index MFA-ILT by projecting onto lumen surface a measure of the ILT thickness. From the physical point of view, hemodynamical indexes describe the mechanical stimuli at which the luminal surface of the vessel wall is subject to, due to blood flow. Specifically, we consider the time-averaged wall shear stress and the oscillatory shear index. The first index provides a measurement of the averaged magnitude of the shear stress; the second index measures the rate of change of shear stress. To reconstruct the hemodynamical indexes, we build in silico three-dimensional models. We use the same physical parameters and boundary conditions for all the aneurysms in the sample. The computer simulations do not require any additional invasive patient examination. We consider eleven cases of abdominal aortic aneurysms spanning a wide range of different morphological features. All the cases are characterized by a thin intraluminal thrombus. We can, therefore, assume that the lumen we currently observe does not significantly differ from the one before the thrombus deposition. Our results suggest that the value of wall shear stresses and intraluminal thrombus deposition are correlated. Moreover, we conclude that in six cases time-averaged wall shear stress provides a preliminary indication of the area at risk of thrombus deposition.

AngioLab--a software tool for morphological analysis and endovascular treatment planning of intracranial aneurysms.

Determining whether and how an intracranial aneurysm should be treated is a tough decision that clinicians face everyday. Emerging computational tools could help clinicians analyze clinical data and make these decisions. AngioLab is a single graphical user interface, developed on top of the open source framework GIMIAS, that integrates some of the latest image analysis and computational modeling tools for intracranial aneurysms. Two workflows are available: Advanced Morphological Analysis (AMA) and Endovascular Treatment Planning (ETP). AngioLab has been evaluated by a total of 62 clinicians, who considered the information provided by AngioLab relevant and meaningful. They acknowledged the emerging need of these type of tools and the potential impact they might have on the clinical decision-making process.