Horizontal motion of the objects in dbt system

[melikturker]

Hi. I have encountered a point of confusion. I have clinical data obtained from a GE Pristina DBT machine and am trying to reconstruct images from these projections using LAVI. The outputs are largely as expected. However, we are facing some issues when trying to visualize the setup in a 3D Cartesian coordinate system.

Even though the configuration settings in our DICOM files do not match exactly with the GE configuration in LAVI, the system still works. The relative positions of the detector, source, and patient are available, but some values are missing in both the DICOM files and LAVI. For instance, from a bird's eye view of the X-ray source to the detector, where exactly does the source lie on the detector? The Source to Detector Distance (DSD) provides the vertical distance, but I couldn't find the parameter that indicates the horizontal position of the X-ray source relative to the detector's plane. Is this DSD the perpendicular distance from the exact center of the detector, the midpoint of the detector's edge, or another point?

In the DBT setup, the patient is positioned at the edge of the detector. Therefore, if the X-ray source is directly above the midpoint of the detector's edge, can we consider the simulated model as a half-cone beam?

[rodrigovimieiro]

For instance, from a bird's eye view of the X-ray source to the detector, where exactly does the source lie on the detector?

The source projection is located at (0, 0). See the manual here

but I couldn't find the parameter that indicates the horizontal position of the X-ray source relative to the detector's plane

The source does not move, only rotates. For DBT you cannot set shifts in the tube location. At least there is no configuration here.

Is this DSD the perpendicular distance from the exact center of the detector, the midpoint of the detector's edge, or another point?

DSD stands for Distance from source to detector. It is just the height of the tube at the angle of 0°. See the geometry plot here

Therefore, if the X-ray source is directly above the midpoint of the detector's edge, can we consider the simulated model as a half-cone beam?

Yes, DBT is half-cone beam

[melikturker]

Thank you very much.