In radiation therapy precision and speed are foremost requirements for high patient throughput. Accurate planning and careful positioning are the keys of all treatment procedures.
LAP positioning lasers display very fine, long lines on the isocenter of the machines, so the patient can be quickly and accurately placed on the couch in a reproducible position. LAP lasers set the standards in line quality, stability, reliability and ease of use.

Laser QA for MRI has the same goal as laser QA for CT.

That is:

I. To ensure that the lasers are parallel to each axis

II. They are zeroed coincident with Isocenter

III. An object aligned to the crosshairs of the lasers can be brought into the scanner isocenter.

The significant difference is, a CT Phantom, such as the Wilke phantom cannot be used, as it is made of material that does not resonate an image in an MRI.

The Aquarius phantom has four chambers filled with a liquid that allows the scanner to generate enough signal to image.

A cross filled with Copper Sulphate oil also images bright against the darkness of the surrounding Lucite (which does not resonate, thus images black).

When scanning, make sure your scan protocol has no offsets in the X, Y or Z position.

Use smallest slice thickness with no gap.