Vessel Deformation Modeling- Cerebral Arteriovenous Malformation

Veiw figure View Figure

In this paper, we are proposing to address the above gap, by using the WindKessel model for the vessel deformation modeling using lumped model for the asymmetrical and symmetrical networks that simulates the actual neurovascular complexity. Using this approach, the clinicians can measure the cerebral parameters non-invasively.

2. Methodology

The input dataset used for analysis is 3D-Rotational Angiogram dataset, which is obtained from Philips Allure Unit. The following steps are applied to volume image:

1. 3D ROI is drawn for the Vessel Deformed region, automatically propagated to all the slices, by applying interpolation technique.

2. Preprocessing techniques are applied to the ROI by performing enhanced contrast, smoothing algorithm and edge detection algorithm based on intensity.

3. The filtering is applied to remove the noise, we have used various filtering techniques –Mean, Median, Convolve and Gaussian Blur, FFT.

4. The input 3D RA image is used as the input volume of the Brain AVM (BAVM).

5. 3D ROI is drawn for the NIDUS Portion, automatically propagated to all the slices, by applying interpolation technique.

6. Preprocessing techniques are applied to the ROI by performing enhanced contrast, smoothing algorithm and edge detection algorithm based on intensity.

7. The filtering is applied to remove the noise, we have used various filtering techniques –Mean, Median, Convolve and Gaussian Blur, FFT. The flow chart 1.0 shows the methodology steps

Figure 2. Flowchart of Methodology

Download as

Veiw figure View Figure

2.1. Lumped Model Analysis

Windkessel and lumped models are often used to represent blood flow and pressure in the arterial system ^[5]. These lumped models can be derived from electrical circuit analogies where current represents arterial blood flow and voltage represents arterial pressure. Resistances represent arterial and peripheral resistance that occur as a result of viscous dissipation inside the vessels, capacitors represent volume compliance of the vessels that allows them to store large amounts of blood, and inductors represent inertia of the blood. The windkessel model was originally put forward by Stephen Hales in 1733 ^[6] and further developed by Otto Frank in 1899 ^[7]., the equivalent RLC values are calculated using the following equations: Resistance = pressure drop through the channel / flow = 8η L/ π R4 ; l its length and µis the fluid viscosity. R is the radius

(1)

Where µ is blood viscosity, l and A are in respect length and cross section area of each arterial segment. Blood viscosity is a measure of the resistance of blood to flow, which is being deformed by either shear stress or extensional stress. This simulation has considered because blood viscosity will cause resistance against Blood flow crossing.

(2)

Where ρ is blood density.

(3)

Where r, E, h are in respect artery radius, Elasticity module and thickness of arteries. The arterial radius and thickness are calculated from the segmented vessel, which is used for calculating the R, L, C values to generate electrical Model ^{[8, 9, 10]}.

We have derived the electrical model for the symmetrical and asymmetrical network for vessel deformation. The Figure 3 shows the Vessel deformation model for the symmetrical network.

Figure 3. Vessel Deformation Lumped Model

Download as

Veiw figure View Figure

The Figure 4 shows the vessel deformation model for the asymmetrical network, for example a stenoses vessel model for an asymmetry network.

Figure 4. Vesseld Deformation for Asymmetrical Netowrk

Download as

Veiw figure View Figure

Figure 5. MATLAB Implementation

Download as

Veiw figure View Figure