The most accurate way to align a support system such as an L-Frame, grid cabinet, table, or any other support of the tube or cassette holder is with a laser.
There are some antiquated ways of aligning the support systems. Examples are: using square levels, turnbuckles, plumb lines, and plumb bobs. These methods waste x-ray film, and are very time consuming. The most precise way to align the support system is with a laser.
Misrepresentation of the object occurs with unaligned equipment. Image contrast can be reduced by as much as 50%, and patient radiation dose can be increased.
When x-ray equipment is properly aligned with a laser, the central ray of the x-ray tube passes through the center of the grid at 90 degrees, regardless of the distance or angle of the tube and grid cabinet. To document alignment, we use a cassette and a square cube with a lead line in the center of each. Then hang a small chain down the front of the grid cabinet. The cassette and chain locate the center of the grid cabinet, and the square cube centers the headclamps. When you make an x-ray through these objects, they will be precisely superimposed.
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