This study will evaluate ways to improve magnetic resonance angiography (MRA) for diagnosing
atherosclerosis (hardening and narrowing of the arteries).
MRA is a new method for looking at arteries and veins without standard angiography, which
requires inserting a catheter into a blood vessel, injecting a contrast material, and
obtaining X-ray images. Current MRA techniques, however, do not depict the lumen (cavity)
of small vessels well enough to accurately determine the extent of their narrowing. This
study will test image processing methods with the eventual goal of improving MRA accuracy to
the point that it can replace X-ray catheter angiography for diagnosing atherosclerotic
Patients with atherosclerosis who have had conventional angiography at Suburban Hospital in
Bethesda, MD, may be considered for this study. They will be screened with a brief history
and physical examination, and those enrolled will have a MRA scan within 72 hours of their
conventional angiogram. For this procedure, a catheter is placed in a vein in the patient's
arm and the patient lies on a table that slides into a magnetic resonance imaging (MRI)
scanner-a large donut-shaped machine with a magnetic field. Surface coils-flexible, padded
antennae used to improve the quality of the pictures-are wrapped around the patient's legs.
At times during the scan, the patient is asked to hold his or her breath for several
seconds, and a contrast material called gadolinium is injected through the catheter in the
vein. This substance enhances the images of blood flow in the vessels. The procedure
generally takes about an hour and a half, although the actual imaging takes only a small
part of that time.
Contrast Enhanced Magnetic Resonance Angiography (MRA) is a developing technology for the
non-invasive evaluation of arterial and venous structures which does not require x-ray based
catheter angiography. While dramatic progress in MRA has recently been made, there are
still substantial limitations in the accuracy of MRA in grading stenoses and detecting small
accessory vessels. The purpose of this study is to recruit patients with documented
atherosclerotic disease as confirmed on catheter angiography performed at Suburban Hospital
for evaluation with state-of-the-art MRA on MRI units, also at Suburban Hospital. We intend
to test new surface coils, new pulse sequence designs, and advanced image processing
algorithms in order to improve MRA accuracy to the point that a large-scale study of MRA vs.
conventional angiography is possible. The goal of this pilot study is to improve MRA to the
point that it can reliably replace diagnostic x-ray catheter angiography in the evaluation
of patients with atherosclerotic disease.
Patient must be willing to participate in the study.
Patient must have documented atherosclerotic disease of an extracranial vessel by
angiography performed within 72 hours of the MRA.
Patient must be referred by a physician who is caring for the patient and to whom the
results will be provided.
Patient must be clinically stable and be judged by their physician able to tolerate lying
in the MR gantry for up to 1.5 hours.
Patient must have serum Creatinine value less than 3.0mg/dl.
Must not have any contraindication for MRI including: pacemaker or other implanted
electronic device; cochlear implants; metal in the eye; embedded shrapnel fragments;
cerebral aneurysm clips; or medical Infusion pumps.
Must not have an allergy to Gadolinium based contrast media.
Must not have unsatisfactory performance status as judged by the referring physician such
that the patient could not tolerate an MRI scan for 1.5 hours. Examples of medical
conditions that would not be accepted would include unstable angina, dyspnea at rest,
severe pain at rest, and severe back pain.
Must not have intercurrent illness that requires treatment that would be jeopardized by
the MRA scan.
Subjects must not require sedation for MRI studies other than administered normally for a
Must not be pregnant.
Must not be nursing mothers.