Medical solutions

3D image processing

Materialise's Interactive Medical Image Control System (MIMICS) is an interactive tool for the visualization and segmentation of CT images as well as MRI images and 3D rendering of objects. Therefore, in the medical field MIMICS can be used for diagnostic, operation planning or rehearsal purposes. A very flexible interface to rapid prototyping systems is included for building distinctive segmentation objects.

The software enables the surgeon or the radiologist to control and correct the segmentation of CT-scans and MRI-scans. For instance, image artifacts coming from metal implants can easily be removed. The object(s) to be visualized and/or produced can be defined exactly by medical staff. No technical knowledge is needed for creating on screen 3D visualizations of medical objects (a crane, pelvis, etc.)

MIMICS is a general purpose segmentation program for gray value images. It can process any number of 2D image slices (rectangular images are allowed). The only restriction is the physical memory of your computer.

The interface created to process the images provides several segmentation and visualisation tools.

Segmentation tools

In Mimics, segmentation masks are used to highlight regions of interest. Mimics enables you to define and process images with several different segmentation masks.
To create and modify these masks the following functions are used:

Thresholding:

Thresholding is the first action performed to create a segmentation mask. You can select a region of interest by defining a range of grey values. The boundaries of that range are the lower and upper threshold value. All pixels with a grey value in that range will be highlighted in a mask.

Region Growing:

Region growing will eliminate noise and separate structures that are not connected.

Editing (Draw, Erase, Local Threshold):

Manual editing functions make it possible to draw, erase or restore parts of images with a local threshold value. Editing is typically used for eliminating artifacts and to separate structures.

Dynamic Region Growing:

Dynamic region growing segments an object based on the connectivity of grey values in a certain grey value range. It allows for easy segmentation of tendons and nerves in CT images, as well as providing an overall useful tool for working with MRI images.

Morphology Operations:

Morphology operations act on the 'form' of a segmentation mask (Erode, Dilate, Open and Close). All these functions remove or add pixels from the source mask and copy the results to a target mask. This tool is extremely effective when working with MRI images.

Boolean Operations:

Boolean operations allow you to make different combinations of two segmentation masks (Subtraction, Union and Intersection). These operations are very useful for reducing the work needed to separate two joints.

Cavity Fill:

Cavity Fill fills the internal gaps of a selected mask and copies the result to a new mask. The filling process can be applied in 2D.

Cavity Fill from Polylines:

Cavity Fill from Polylines creates a segmentation mask, starting from a polyline set. This tool is very useful for filling internal cavities.

Visualisation & measurement tools

Visualisation:

Mimics displays the image data in several ways, each providing unique information. Mimics divides the screen into three views: the original axial view of the image, and resliced data making up the coronal and sagittal views. Mimics includes several visualisation functions such as contrast enhancement, panning, zooming and rotating of calculated 3D images. Colour scales are used to enhance small differences in the soft tissue or the bone. Mimics displays the alignment or scout image and indicates the position of the axial slices in it.

3D Rendering and 3D information:
Mimics provides a flexible interface for quickly calculating a 3D model of the region of interest. Therefore you can set parameters for resolution and filtering. Information about height, width, volume, surface, etc. is available for every 3D model. Mimics can display the 3D model in any of the windows with visualisation functions that include real-time rotation, pan, zoom and transparency. The ability to apply advanced rendering with OpenGL hardware acceleration offers high-quality rendering including Gouraud shading for optimal display of the 3D objects.

Reslicing:
Two reslicing tools are available: the on-line reslice tool and the export resliced project tool. On-line reslicing allows you to display cross-sectional and parallel images that are orthogonal and along a user-drawn curve in the axial view. Users can define several different reslice curves that are saved in the Mimics project.
The export resliced project tool has an easy to use interface that allows you to export a resliced Mimics projects along a user-drawn line. This line can be drawn in any view and in any direction.

Measurements:
Point to point:

With Mimics, you can perform point-to-point measurements on both the 2D slices and the 3D reconstructions.


Profile line and gray value measurement:
A profile line displays an intensity profile of the grey values along a user-defined line. You can make accurate measurements based on the grey values using three methods: the threshold method, the fourpoint method and the four-interval method. These methods are ideal for technical CT-users.

Density measurements:
Perform density measurements in an ellipse or rectangle: area, mean, grey value and standard deviation are displayed. All measurements are saved in the project file and are listed in the Project Management.



Labels: Labels can be used to add information to your 3D models. Labels can be placed in any direction, the font can be changed and the label can be moved in all views. Only when you export the mask with label in a sliced format you are restricted to place the label in horizontal or vertical direction.



Reporting:
The enhanced Print function allows you to print a complete report with general project information, 3D views and all axial and resliced images. You can make screenshots from all views and print them or save them to a file (BMP or JPEG). You can also export images in BMP or JPEG format in 1:1 scale.



Project Management:
The Project Management dialog provides an ideal way to organise and interact with the data (Segmentation Masks, 3D Renderings, Polylines, STL files, Measurements, Profile Lines, etc.) and their properties.