Phantom Rotation

Center of Phantom

The center of the phantom described is the pixel coordinate in the center of the phantom (in pixels).

Rotation

Degrees of phantom rotation around the z-axis.

Tilt

Degrees of phantom rotation around the x-axis.

Yaw

Degrees of phantom rotation around the y-axis.

Positioning Catphan® in Scanner

The Catphan® phantom is positioned in the CT scanner by mounting it on the case.

• Place the phantom case on the gantry end of the table with the box hinges away from the gantry. It is best to place the box directly on the table and not on the table pads.
• Open the box, rotating the lid back 180°. If you are using an annulus, additional weight will need to be placed in the box to counterweigh the phantom. The patient straps can be used for additional stability.
• Remove the phantom from the box and hang the Catphan® from the gantry end of the box. Make sure the box is stable with the weight of the phantom and is adequately counterweighed to prevent tipping.
• Use the level and adjusting thumb screws to level the Catphan®.
• Once the phantom is level, slide the phantom along the end of the box to align the section center dots on the top of the phantom with the x axis alignment light.
• Use the table height and indexing drives to center the first section’s (CTP401 or CTP404, Slice Geometry) alignment dots on the side and top of the phantom with the scanner alignment lights.