GE CT-9800

GE MEDICAL SYSTEMS CT 9800 QUICK SYSTEM
Rev. 12 Direction 18000
6-9A-2
Directions in the gantry geometry are defined as follows:
• Theta - Along the tangent to gantry rotation; i.e., clockwise (+) or counter clockwise (-) on the rotating
structure. 0° theta is defined with the tube unit at bottom dead center.
• Z Axis - Parallel to the axis of gantry rotation; i.e., towards or away from the patient table, or in the
direction of cradle motion. + is toward the table, - is away from the table.
• Radial - Along the radius from the center of gantry rotation; i.e., in and out from the gantry isocenter.
ILLUSTRATION 6-9A-2