Maracas (MAgnetic Resonance Angiography Computer Assisted analysiS)

An interactive software for visualization and analysis of blood vessels in 3D MRA, providing automatic quantification of the arterial stenoses.

MARACAS is an assistance tool for the diagnosis, treatment planning and follow-up of arterial diseases. It combines the most commonly used three-dimensional visualization techniques with original image processing methods applied to the analysis of vascular morphology in MRA. MARACAS functionality includes:

More details can be found by clicking here.

Series and volume of interest selection

When MARACAS is started, the Patient List window appears (Fig. 1). This window enables the user to retrieve and load image data. MARACAS automatically reads and displays patient and scanner information included in the DICOM header. Each patient can include multiple series of image data. Hence, when the user selects a patient, its constitutive series are listed.

Figure 1 – Patient List window

One series can be selected and then displayed in a normal size in the Series window (Fig. 2). Once the images are loaded, MARACAS gives access to a vast array of manipulation tools, including slice-by-slice visualization, zoom, as well as contrast control by window width and level adjustments. In order to reconstruct, from a slice series, the 3D volume of interest (VOI) to be processed, the user needs to select the first and the last slice to be included in the volume. Then, he/she can delimitate the region to be analyzed (i.e. pathological region).

Figure 2 – Series window.

3D visualization

Once the 3D VOI is reconstructed, it is displayed in the 3D Visualization window by means of a surface rending technique (Fig. 3). It can be performed from any viewing angle, panned and zoomed.

Figure 3 - 3D visualization window.

3D vessel tracking and automatic quantification

Vessel-tracking process is divided into two steps. First, the extraction of the vessel central axis is performed. Contours are then detected in the planes locally orthogonal to the centerline. See the "description of the method" for more details. MARACAS supplies automatic measurements aimed at an accurate quantitative analysis of vascular morphology. (Fig. 4).

Figure 4 - Automatic quantification along the vessel centerline.