In this assignment you will visualize a CT-scan of the abdominal region of a human. You will also visualize a pre-segmented "mask" that shows where in the volume the liver is located. You shall create a small application that can be used to compare the mask with the original volume. Such an application could for example be used by a physician to verify that the mask, which might have been generated with an automatic segmentation algorithm, is correct. The CT dataset is available here. The CT scan is stored as a vtkStructuredPoints dataset of signed 16-bit data (short) representing Hounsfield units. The segmented liver can be found here. It is represented as a binary 8-bit (unsigned char) volume where the liver voxels have the value 255 and the background voxels have the value 0. A python script to start from can be found here.

Part 1 - Task

Display the segmented liver mask as a solid surface. Which isovalue do you choose? Is it a good segmentation?

Display the CT-scan with multi planar reformatting (MPR). Three axes oriented planes are OK. I recommend you to use vtkImagePlaneWidget that provide means to browse and rotate the plane, change contrast, and to probe the data.

Probe the image with the mouse cursor and examine the density values of bone, air, and soft tissue.

Provide a keyboard interface to switch on/off the rendering of the segmented liver (can be controlled with the actor).