The Wilke Phantom can be used to check the alignment of the internal and external lasers to the radiographic center of CT and PET/CT units and to verify lateral gantry angle.  It can also be used with accelerator units to check vertical and lateral gantry angles, laser alignment and vertical table movement.

The Mini-Phantom is made of clear acrylic measuring 15 cm×13 cm×4 cm thick.  One 15 cm×13 cm side has centering scribe lines that go all the way across the phantom.  All other sides are scribed through the center and two opposite sides are also scribed at 5 cm from center.  The scribe lines are 2 mm wide and white for ease of viewing the lasers.  All other sides have three pinholes, one at center and two at 5 cm from center. 
The two large holes are 5 mm and are 5.5 cm and 4 cm apart in distance from corners, and 6.5 cm and 9 cm from base respectively.