Imaging for iliac vein compression is a planning topic, not an emergency. No source below gives an urgency level for it, and a sudden change in a leg should go to a clinician right away.
Cleveland Clinic explains how the condition is confirmed and how common it is. This page reports what it says and leaves the choice of test to your clinician.
How the condition is confirmed
Cleveland Clinic says: "The only way to know for sure if you have the condition is to have imaging tests that show your right iliac artery compressing your left iliac vein."
The page does not name the tests in the passage used here, so ask your clinic which one it would use.
How often compression turns up
On how often this happens, Cleveland Clinic says: "Iliac vein compression is common, occurring in about 1 in 5 people."
It also notes a gap between compression and diagnosis: "However, many people with iliac vein compression don’t have a formal diagnosis of May-Thurner syndrome."
Steps before asking about imaging
- Write down the symptoms that made you wonder, and when they started.
- Prepare questions, such as the ones in this list of what to ask your doctor about varicose veins.
- Ask which test your clinic would use and what it is meant to show.
Where the sources differ
One publisher is quoted here, so no disagreement is marked. Compression is called common, yet many people with it have no formal diagnosis. Ask your clinician what a finding on a scan would mean for you. A vascular surgeons' society page on varicose veins shows how a professional body frames vein care more broadly.
Where self-care ends
Reading and preparing questions are yours to do. Ordering and reading a scan is not. If you are wondering about stockings while you wait, this guide to compression stockings explains what they are. Whether they suit you is a question for your clinician.