I have an xyz coordinate of 31.4, -39.6, -216.4, but the corresponding RAS coordinates are -34.88, 38.816, -204.997. I find that there are deviations in the coordinates when importing. This is not just a simple relationship of reversing the xy axes. Could anyone please tell me what the cause is and how to solve it?
My dicom’s detail is as follows:
What coordinate system do you refer to as XYZ? What are the origin, spacing, and axis directions?
Actually, i don’t know the origin coordinate system. I only know the coordinate is from FluoroCT, and we want to import the mark to 3Dslicer now. The spacing is [0.43, 0. 43, 0.625]. The origin is [78.132, 153.069, -275.262]. Can you give me some advice?
Assuming that by “FluoroCT” you mean CBCT reconstruction by a fluoro (C-arm) that is saved in DICOM, the coordinates are in LPS coordinate system. You can convert between LPS and RAS coordinate systems by inverting the sign of the first two coordinates.