I just received an email today asking for an explanation on obliques... I'm fairly certain that it was about ribs, but I thought I would go ahead and post this because it can be difficult to understand why we position oblique ribs the way we do. The rule of thumb for most obliques is to simply place the anatomy of interest closest to the image receptor to visualize the most detail possible. This does not apply with every oblique view of the ribs, however.
Reasons vary for why we position most body parts in certain obliques, and ribs are very different as well. Typically, if an area of interest is anterior, an anterior oblique is performed (RAO or LAO), and if an area of interest is posterior, a posterior oblique is performed (RPO or LPO).
Posterior rib pain: If your patient is complaining of right posterior oblique pain, you would perform RPO. If the pain is left posterior, perform LPO.
Anterior rib pain (this is where it gets tricky): If there is right anterior rib pain, perform an LAO. This seems like the opposite of what should be done, but if a RAO is performed, the thoracic spine will superimpose the area of interest. You need to move the spine out of the way with an LAO. This position still places the anterior ribs closer than a posterior oblique would, providing better detail by getting the anatomy closer to the image receptor, and still prevents the superimposition of the spine. If there's left anterior rib pain, perform an RAO for the same reason - get the part of interest closer to the image receptor, and move the spine out of the way.
It's always a good idea to mark the area of interest with a bb marker or annotate some arrows on the image just to help out the Physicians viewing the images as well.
Thank you for your help.
ReplyDeleteWould you be able to post any pictures as examples of this technique for clarification?
ReplyDeleteI can certainly try to find some... give me a few days :-)
ReplyDeleteSure. Thanks. :)
ReplyDeleteWhen I was still in school the Rib obliques were so confusing! In work I always try to do the LPO/RPO ones but obviously...not all patients all the same. You have very nice skills in teaching!
ReplyDelete@ anonymous regarding images: I'm sorry, but I haven't been able to find many rib images lately... If anyone wants to send me some, I can post them.
ReplyDelete@ X-Ray Chick: Thanks! I hope I can help a little bit at least.
ReplyDeleteI teach this: PA AWAY...Elongay...
ReplyDeleteThe primary goal is to elongate the ribs of interest. So if the patient has anterior rib pain, they would be placed in a PA Oblique, or RAO/LAO, and the side of interest will be away from the image receptor. So if the student can remember that, then it is the opposite when you turn the patient AP.
I teach this: PA AWAY...Elongay...
ReplyDeleteThe primary goal is to elongate the ribs of interest. So if the patient has anterior rib pain, they would be placed in a PA Oblique, or RAO/LAO, and the side of interest will be away from the image receptor. So if the student can remember that, then it is the opposite when you turn the patient AP.
@Tiana: I like it!
ReplyDeletehow about trauma patient? if the injury don't mention about which side; either anteriorly or posteriorly rib fracture.
ReplyDeleteI suppose it depends on how bad of a trauma... if they're only capable of lying down, then you don't have much choice. If they're on a back board, you're not going to be able to acquire obliques. If they can stand, but have pain due to trauma, they should be able to identify where it hurts... you need to try to get the area of interest as close to the image receptor as possible with the proper respective oblique.
ReplyDelete