This study will examine the use of magnetic resonance imaging (MRI) instead of x-rays to
guide angioplasty in patients who require these treatments to treat blockages in leg
arteries. Angioplasty is a procedure in which a balloon is inflated in a blocked artery to
improve blood flow. MRI uses a magnetic field and radio waves rather than x-rays to show
pictures of body tissues and organs. MRI shows all soft tissue, including the arteries,
blood, and other organs, while the usual x-ray technique shows only the lumen of the artery
when it is filled with dye, but not the vessel walls.
Patients 18 years of age and older who require angioplasty with or without stenting to
restore blood flow to the leg may be eligible for this study.
Participants undergo the usual angioplasty procedure. The skin in the patient's groin area
is numbed and a catheter is placed into the groin artery. The patient is given a
blood-thinning medicine, and then other catheters are inserted to measure blood pressure and
to inject a contrast dye to take pictures. Balloon catheters are inflated to open the
blockage and, if needed, stents are put in place to maintain the opening. When the blood
thinner wears off, the catheters are removed.
Most of the procedure is conducted using MRI instead of X-rays to visualize the arteries and
blockages. The patient is moved back and forth between the x-ray and MRI machines in a
specially designed laboratory. If necessary, stenting, placement of a wire mesh to hold open
the artery, is done using conventional x-ray techniques.
The entire procedure, including MRI, takes up to 4 hours.
Cardiovascular interventional procedures are minimally-invasive, catheter-based treatments
such as coronary artery angioplasty and stenting. These procedures generally can be
conducted on awake patients with few complications, and were developed as alternatives to
conventional open surgery. Conventional cardiovascular interventional procedures are
conducted by physician manipulating medical devices inside patients under the guidance of
We have developed minimally-invasive cardiovascular interventional procedures using
real-time magnetic resonance imaging. These procedures have the advantage of excellent
imaging without surgery and without ionizing radiation exposure or toxic contrast agents
(dyes). Moreover, because real time MRI can produce excellent images of soft tissue, blood,
and of three-dimensional structures, it may be possible to guide minimally-invasive
procedures not possible even with invasive surgery.
A state-of-the-art combined X-ray and MRI interventional suite has been constructed and
equipped with real-time MRI image reconstruction for interventional experiments, patient
monitoring and transport equipment for dual imaging modalities, and large-mammal preclinical
simulation experiments. Preclinical experiments in a porcine model of surgical aortic
coarctation have shown that real-time MRI guided percutaneous intervention can be conducted
using entirely commercially-available devices approved by the US Food and Drug
The goal of this protocol is to test clinical peripheral artery revascularization procedures
guided wholly-or in part by real-time MRI.
- INCLUSION CRITERIA:
Patients with known or suspected cardiovascular disease will be eligible for participation
in this protocol. The patient is eligible under the following conditions:
- Patients age is greater than 18 years of age.
- Undergoing a clinically-indicated therapeutic peripheral artery catheterization
- Target peripheral artery is aorto-illac or femoropopliteal artery.
- Target peripheral artery stenoses, not occlusions, evident on magnetic resonance or
Patients with absolute contraindications to MRI scanning will be excluded. These
contraindications include patients with the following devices:
- Implanted cardiac pacemaker or defibrillator.
- Central nervous system aneurysm clips.
- Implanted neural stimulator.
- Cochlear implant.
- Ocular foreign body (e.g. metal shavings).
- Insulin pump.
- Metal shrapnel or bullet.