So you've done your cross-table lateral C-spine and the Radiologist says "go ahead and finish the series without removing the collar," thinking there is a possibility of a fracture. The CT tech has been called in and you've got 30 minutes to obtain the rest of your series without moving the patient.
The AP and odontoid views go well after some creative tube angulation, but you're not quite sure you remember how to perform trauma obliques and your facility has misplaced their late 1970's version of Merrill's (all of this is hypothetical of course).
The best results can be obtained with proper placement of the film. Depending on the type of image receptor you are using (conventional film, CR, or DR), just remember one thing... if using a grid, place it crosswise so the gridlines run parallel with your tube angulation.
Plan to place the top of your film at the TEA (top of the ear attachment), or the center of your film at the level of C-4 / thyroid cartilage.
Center the spine over one half of your cassette (depending on which oblique you are performing first. The picture is simulating an LPO. This is a good starting point. The adjustment of your film from the patient's right to left will depend on body habitus. For instance, if there is more object to image distance (OID - from the spine itself to the IR) such as in larger patients, you may have to shift the cassette farther away from the central ray. If the patient is small (with small OID), the spine will possibly be centered more to the middle of the cassette.
Angle the tube 45 degrees entering the level of C-4 and approximately the level of the gonion. Just remember your CR will enter anteriorly to the EAM and take into consideration any minute skull rotation that will throw your CR off (don't center at the gonion if the patient's head is rotated 30 degrees to one side).
Perform the exact opposite of this oblique on the opposite side and you are home free!
The AP and odontoid views go well after some creative tube angulation, but you're not quite sure you remember how to perform trauma obliques and your facility has misplaced their late 1970's version of Merrill's (all of this is hypothetical of course).
The best results can be obtained with proper placement of the film. Depending on the type of image receptor you are using (conventional film, CR, or DR), just remember one thing... if using a grid, place it crosswise so the gridlines run parallel with your tube angulation.
Plan to place the top of your film at the TEA (top of the ear attachment), or the center of your film at the level of C-4 / thyroid cartilage.
Center the spine over one half of your cassette (depending on which oblique you are performing first. The picture is simulating an LPO. This is a good starting point. The adjustment of your film from the patient's right to left will depend on body habitus. For instance, if there is more object to image distance (OID - from the spine itself to the IR) such as in larger patients, you may have to shift the cassette farther away from the central ray. If the patient is small (with small OID), the spine will possibly be centered more to the middle of the cassette.
Angle the tube 45 degrees entering the level of C-4 and approximately the level of the gonion. Just remember your CR will enter anteriorly to the EAM and take into consideration any minute skull rotation that will throw your CR off (don't center at the gonion if the patient's head is rotated 30 degrees to one side).
Perform the exact opposite of this oblique on the opposite side and you are home free!
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