4.3 Kango Cave Buck - Fossil

4.3.1 Background

The National Museum at Bloemfontein was approached. As this RE technology is still in the developing stage locally, medical applications are difficult to come by. This fossil related case study was selected, as there is very little chance that the fossil may be damaged during the process. The electronic data as well as the final product, a prototype, will also be used to verify this archaeological finding. This buck fossil was found in the Kango caves near Oudtshoorn, Western Cape.

4.3.2 Conclusion

This fossil was scanned twice. The first time the fossil was scanned, the data was reconstructed at 3mm thick slice and 3mm thick intervals. This resulted in a staircase effect and poor surface finish. A great deal of data was also lost due to the coarse scanning reconstruction, low bone density and thin bone sections . Mr. Brink requested that we look into this problem as it was not acceptable to prove the archaeological finding. The second scan was reconstructed to 1mm thick slices and 1mm intervals. This images clearly show better results. There still are detail missing, most probably due to the thin bone sections and low bone density. More experimenting may need to be done to fine-tune the CAT scanner and settings to achieve the optimum conditions. An alternative method of capturing this data may be the DIGIBOTICS 4-axis laser scanner.

The data was stored in three sets. The radiographer in sets of about 45 slices stored data. This was done to allow the X-ray tube to cool down during scanning and storing stages. It also allowed a time delay for the computer to process the data. The data was stored in on the hard drive in different directories and processed separately. Surface files were generated (.srf). The various .srf files could not be joined at a later stage for 3D image processing, as they were stored indifferent directories. Moving the files into one directory did not solve the problem. The original CAT 2D images were copied to a new directory where it was converted and processed the data again, to view it as one entity. Images

3D Reconstruction of the Kango Fossil

Figure 4.3.2 .2

3D Reconstruction of the Kango Fossil


4.3.3 Kango Cave Buck Data Sheet:
  Description Options (Default) Data
1 CT Image Names   E6282S10I*.CT
2 Patient/Project Name   2S10I.pat, kbok.pat
3 Number of First Input Image   1/21
4 Number of Last Input Image   288/306
5 Number of First Output Image   000
7 Horisontal Nr. Of Image Pixels 0 to 65535 (265,512,1024) 512
8 Vertical Nr. Of Image Pixels 0 to 65535 (265,512,1024) 512
9 Number of Images per File (1) 1
10 File Swap Format (0,3) 0,3 CCGEADVA
11 Pixel Type B,UB,S,US,L,UL,F -
12 Header Size *see formula below -
13 Inter Image Header Size 0 -
14 Add Value 0 to 4095 -
15 Scale Value 0 to 4095 -
16 Table Position (mm) 0
17 Distance Between Slices (mm) 1
18 Slice thickness (mm) 1
19 Pixel Size SQ. F.O.R./Nr. Hor. Pixels (mm) 0.47
20 Gantry Tilt Angle Degrees 0
21 Field of Reconstruction/View (mm) 240
22 Number of Images   288
23 File Size of CAT Image kb 270-280
24 File Size of Converted Image kb 20-35
25 .3dd file size Mb 10.56 (.srf)
26 .STL file size Mb -
27 RP Method (SLA,FDM,OTHER) -
28 .IGS file size Mb -
29 RP Slice file size Mb -
30 RP Download File size Mb -
31 Grow Time Hour -
32 Tip size (T12, T25) -
33 Slice Thickness (0.01", 0.014") -
34 Finishing Time Hour -
35 Processing Time Hour 3
36 Data Retrieval Time Hour 4
37 Total Cost Rand =2*7*150+1166


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