Whole Body Magnetic Resonance Angiography in Ischemic Patients at 1.5 and 3T

Whole Body Magnetic Resonance Angiography in Patients With Symptomatic Peripheral Ischemia: A Comparison Between 1.5 and 3T MRI-systems

To investigate the diagnostic performance of whole body magnetic resonance angiography (WB-MRA) using two different magnetic resonance scanners at a field strength of 1.5 and 3T. The hypothesis is that use of the 3T system gives superior signals from the investigated arteries, when compared with 1.5T.

Atherosclerosis of the lower leg arteries is a common disease. Patients with this condition has symptoms of ischemia, for instance intermittent claudication (pain during exercise). Diagnosis of atherosclerosis in the legs is normally done with an interventional x-ray-based angiography (DSA- digital subtraction angiography). This is uncomfortable for the patient, and associated with risks of complications (bleeding, vascular damage, embolism).A novel approach to diagnosing atherosclerosis is the use of magnetic resonance angiography. A variant of this is the whole body magnetic resonance angiography(WB-MRA), that produce a picture of the arteries in almost the whole body (excluding the coronary arteries). WB-MRA has a number of advantages compared to DSA. It does not use ionizing radiation, is not invasive, uses a contrast medium with fewer side affects and finally gives a covers a great deal of the arteries in the body.

This study will compare WB-MRA with DSA in patients with symptoms of peripheral atherosclerosis in the lower legs.

All the patients will undergo arterial first pass whole-body MRA in the 3T-system. This will be followed by a WB-MRA steady state examination which can be performed because we use the intravascular contrast medium Vasovist, that has a prolonged intravascular life. The steady state examination will be performed in both the 3T and the 1.5T MR-system. Half the patients will have the steady state examination performed first in the 3T and then the 1.5T-system. The other half will go to the 1.5T-system first and then return to the 3T-system.

Inclusion Criteria:

• Symptomatic lower extremity ischemia (claudication, ischemic wounds) Referred to digital subtraction angiography (DSA)

Exclusion Criteria:

• Renal insufficiency (GFR < 30 ml/min)
• Contra-indications for MRI-examination (claustrophobia, metal-implants, pacemaker)
• Dementia
• Pregnancy/lactation
• Allergy to gadolinium based MRI contrast agents
• Acute disease