3D Visualization of Bone Metastases

Volumetric Findings

A helical scan 10 mm slice thickness was obtained to establish the possible presence of metastatic cancer. The scan was performed using a mobile CT scanner which visits Van Buren County Hospital on a weekly basis. 3D surface rendering of the bone clearly showed multiple foci of bone metatastases within the pelvis and spine. Pleural effusion present in the posterior, lower lungs particulary the left lung.

Mpeg movies

Original Helical CT data set

Original trans axial, 44 slice, 10 mm thick Helical CT data set of a patient with metastatic cancer.

Shaded Surface Display (SSD)

Shaded Surface Display showing the locations of several bone metastases.

Volumetric Tools Applied

Make Analyze Header was necessary to make an appropriate header file for the data set. The appropriate X (pixel dimension), Y (pixel dimension), Z (slice thickness) were used to make the new header file.
Load Analyze Format was used to load the data into VIDA for analysis. Appropriate window and level was chosen to highlight the bone. Then the data set was loaded as an 8 bit image for segmentation.
2D Segmentation First the data set was dimmed by multiplying by 90% so that nothing in the data set would has a value of 255. Next the spine, ribs, and pelvis were extracted using 3D fill, a threshold of 240 and above, setting the output to 255.
Image Flipper was used to flip the data set so that the slices were oriented from foot to head rather than head to foot. This is accomplished by flipping the Z axis. It is neccesary for the data to be oriented from foot to head for Surface Render to work properly.
Surface Renderer was used to extract the 3D skeleton of the patient. A maximum smoothing factor of 3 and interpolation were used because of the data's thick slices (10mm).