Comparative Study of Non-enhanced Versus Contrast Enhanced MR Angiography in Peripheral Arterial Disease on a 3T MR Scanner.

Comparative Study of Non-enhanced Versus Contrast Enhanced MR Angiography in Peripheral Arterial Disease on a 3T MR Scanner.

Magnetic Resonance Angiography (MRA) of the peripheral arteries has become essential in the diagnosis and follow-up of peripheral arterial disease.

In clinical routine, the acquisition uses intravenous injection of a Gadolinium based contrast agent (gadolinium chelates).

Initially, contrast enhanced MR angiography (CE-MRA) was recommended for diabetic patients, elderly patients and\or patients with chronic renal insufficiency presenting a contraindication to CT angiography using iodized contrast agent injection.

However, the increase in nephrogenic systematic fibrosis clinical cases, which would be secondary to gadolinium chelates injection, in patients with chronic renal insufficiency has restricted the use of CE-MRA. More than 500 cases were described to date in the world.

Its occurrence is currently estimated around 4 % for patients in terminal chronic renal insufficiency and its mortality around 30 %.

According to the recommendations of AFSSAPS from August, 2007, two gadolinium contrast agents (Gadodiamide-OMNISCAN *, General Electric HealthCare and Gadopentetate Dimeglumine-MAGNEVIST *, Bayer HealthCare) are contraindicated if the glomerular filtration rate is lower than 30 ml/mn.

Non-contrast enhanced MR angiography (NCE MRA) techniques have been proposed to provide complete and non-invasive investigation of the peripheral vasculature, from the abdominal aorta to the calf, thus offering patients with chronic renal insufficiency a surrogate with no side effects.

Moreover, the use of high field (3T) MR imaging and phased array coils offers high quality images and good signal to noise ratio for peripheral vasculature analysis.

Besides, the acquisition can be repeated if required as it does not require any contrast injection.

The main objective is to evaluate the quality of the NCE images obtained for every investigated station from the abdominal aorta to the calf.

The secondary objective is to compare the diagnostic performances of NCE images with those of CE MRA.

The third objective is to estimate the contribution of automated and dedicated post-processing tools in optimizing the diagnostic quality of the images.

20 patients will be recruited either by the vascular surgery or by the cardiology departments The appointment for MRA of the peripheral arteries on the Siemens 3T MR Scanner will be given as usual.

Inclusion Criteria:

• Any adult patient known or clinically suspected to present a peripheral arterial disease, the assessment of which requires an MRA of the peripheral arteries.
• MRA will be prescribed by the vascular surgery or cardiology departments. The patient should be conscious and cooperative. Clear and intelligible oral and written information will be given to the patient. The patients giving written informed consent will be included in the study.

Exclusion Criteria:

• A contraindication to MRI, in particular pacemakers or implantable defibrillators, cochlear implants, neurosurgical clips, intra-orbital or brain metallic foreign bodies, endo prothesis since less than 4 weeks or osteosynthesis material since less than 6 weeks
• Contraindication to the injection of contrast agent: pregnancy, lactation, history of allergic reaction to contrast agent injection.
• Hemodynamically unstability, acute respiratory failure, a precarious condition or a need for continuous monitoring incompatible with the constraints of MR imaging.
• Age under 18 or under legal protection measure or without social coverage.
• A refusal or inability of obtaining informed consent from the patient.

Patients withdrawing their informed consent will be excluded.