Thanks for the replies. How is flexion and extension done with a supine MRI? I have had a few MRIs in the past and they always put a brace on my head to keep it from moving during the scan. Is there a chance of the upright scan picking up something the supine will miss? I guess I am confused what upright is used for if the same conditions can be seen in supine.
@GypsyGirl, I am planning to send my scans to probably two neurosurgeons to review. Since I likely can do a upright MRI locally I feel I probably should do that as I have never had one done, it may show things that were missed in my neck MRI years ago. Though if flexion and extension can be done supine then it may not matter.
From what I've read and what others have told me, flexion/extension can be sort of done in the supine MRI by using padding. Many radiologists don't know how to do it (it's non standard), and it's difficult to show full range of motion this way. (But some have reported being dx-ed this way, so it's possible.) It's not going to show the full effects of gravity as it would if you were upright, and how big that difference is depends on your ligament laxity. Some people may have no difference in their supine and upright MRIs; for others, it will make the diagnosis that otherwise wouldn't have been made.
Upright needs to be done for Chiari (says Henderson). With instability, upright can make a difference for those with ligament laxity since their supine imaging is likely to come back normal, without significant findings. Upright is usually a lower quality picture (.6 Telsa) vs supine MRIs (lots of 1.5T machines, and some even better 3Ts). Upright for other things seems slightly less defined in general and more based on neurosurgeons' preference.
Severe instability might be seen on supine MRIs (or other imaging). Severe or mild instability doesn't necessarily mean severe or mild symptoms, that's another reason it's hard to guess what's appropriate. People can have disabling symptoms from very small Chiari or "mild" instability, and might be told over and over again that everything is normal. There are also different kinds of instability - vertical, horizontal, rotational. To catch ligamentous failure in imaging, you must take pictures to capture the instability (possibly on bones that look absolutely healthy, with no pathology). For example, a supine MRI in flex/ext might come back normal. But an upright MRI might show vertical instability not apparent without the effects of gravity/sitting up. Or an upright MRI might come back normal, but a rotational CT will show rotational instability that doesn't show up on an upright MRI. Etc.
Neurosurgeons have different preferences, so your best bet is to call your neurosurgeons and ask what's their standard so you can give them what they're best at reading. It's a start. You may need to get other imaging afterwards anyway, depending on what they see in your imaging or find out in your exams.
I hope that helps. I'm writing up a paper for myself and other doctors as a crash course in imaging for EDS; it's not quite finished but I'm glad to send you a copy of the draft to your email if you'd like. It expounds on the things I'm saying here in a more orderly fashion.
(But seriously.)
