How are the different ends of the radiopaque marking grid identified?
The space between lines 1 and 2 is larger than the spaces between the other lines. This can be useful for orientation, as the shown image in the CT control room/on-screen can be different from the patient orientation. The marking grid should be used during planning in CT-guided procedures and to guide the appropriate skin entry point for the procedure.
The first set of images shows the radiopaque marking grid in place overlying the left sacroiliac joint for planning. The inferior portion of the sacroiliac is targeted.
The second set of images shows the needle tip in an intra-articular position with iodinated contrast confirming the correct placement.
Subsequent injection of steroid and local anesthetic was then administered.