Final answer:
Magnetic Resonance Angiography (MRA) is the medical imaging technique that detects blood flow and vessel wall conditions without using a contrast medium, utilizing magnetic properties of blood and radio waves to create detailed images.
Step-by-step explanation:
The procedure that detects blood flow, the condition of vessel walls, and blockages without using a contrast medium is Magnetic Resonance Angiography (MRA).
Magnetic Resonance Angiography is a type of MRI scan that specifically looks at blood vessels and can provide detailed images of arteries without the need for contrast agents that contain iodine, which may cause allergic reactions in some people. Instead, MRA exploits the natural magnetic properties of blood to create its pictures.
While other procedures like cardiac catheterization and nuclear perfusion study often require contrast mediums to visualize the cardiovascular structure, MRA can produce high-resolution images of the arteries and detect narrowings or blockages solely with the use of powerful magnets and radio waves. This method is particularly useful for patients with renal insufficiency or those who are allergic to conventional contrast agents.