The work was carried out in five phases:
Phase 1: Head CT data acquisition.
The studies were performed on a General Electric ® LightSpeed™ VCT 16 scan.
An anthropomorphic phantom head computed Tomography (CT) was performed.
The protocol used is presented in Table 1.
After the images acquisition in the DICOM format,
quality improvement was performed in two post-processing software: 3D Slicer® and Meshmixer®.
Phase 2: Head CT data post-processing.
Use of 3D Slicer® software viewing with the aid of the Projection Volume Rendering Technique throughout the volume of interest in a three-dimensional perspective.
The main goal was to make evident the information inherent to the soft tissues,
performing the segmentation with soft tissues threshold,
and manipulating the grey scale to achieve a correct visualization and definition.
With post-processing images in DICOM format,
it was necessary to establish compatibility between the area of radiology (CT) and 3D Printing.
Phase 3: DICOM data format conversion to 3D printing compatible format (STL).
First we selected the STL format (Standard Template Library) to ensure compatibility,
performing the conversion on the 3D Slicer® software.
New post-processing procedures were made,
using the Meshmixer ® software.
At this stage,
objects (support of skull and immobilization system) were eliminated,
since,
in this study,
they don’t represent areas of interest for 3D printing.
It was redefined the volume of interest,
aiming attainment of a quality object.
Improvement of images quality was achieved by reducing the ladder effect and the blurring present in the 3D image.
Phase 4: 3D printing of the developed object.
The material previously obtained was analyzed,
concluding that it was possible the production of an anatomical part.
Proceeded to file conversion to AM format,
throughout Object Studio® software.
After this conversion and setting of the printing parameters the object was printed.
The AM equipment was the Object,
Connex 260V®,
a polyjet technology,
and a rubber like material was used (Tangoblack Plus®).
Phase 5: Head CT acquisition with the printed object.
After printing the object,
a new head CT study was performed with the printed object over the nose area.
In this CT study,
the same position and acquisition parameters were used,
and matching printed object with the correspondent anatomic area.
Figure 1 demonstrates the five methodology phases to obtain and validate a 3D printed object.