Technical Development of Cardiovascular Magnetic Resonance Imaging
Technical Development of Cardiovascular Magnetic Resonance Imaging
This study will explore new ways of using magnetic resonance imaging (MRI) to evaluate the
 heart and blood vessels of patients with cardiovascular disease, including better detection
 of myocardial infarction (heart attack) and blockage of heart and leg arteries.

 Patients 18 years of age and older with cardiovascular disease may be eligible for this
 study.

 All participants will have magnetic resonance imaging of the heart. MRI uses a magnetic field
 and radio waves to show structural and chemical changes in tissues. For the procedure, the
 patient lies on a table surrounded by a metal cylinder (the scanner). A 'gadolinium contrast'
 material may be injected into the patient s vein during part of the study to brighten the
 images. Patients wear earplugs during the scan to muffle loud knocking sounds caused by the
 electrical switching of the magnetic fields. They will be asked to hold their breath
 intermittently for 5 to 20 seconds during the scan. They will be monitored with an
 electrocardiogram (EKG) during the procedure and will be in contact by intercom at all times
 with the person performing the scan. Patients can request to stop the study and come out of
 the scanner at any time. The procedure may last from 30 to 90 minutes. An echocardiogram a
 test that uses sound waves to produce pictures of the heart and blood vessels-may be done to
 confirm the MRI findings. In addition, patients may undergo one or more of the following
 optional studies:

 -  Dobutamine stress MRI - This test uses dobutamine-a medicine that simulates exercise by
 increasing heart rate and heart function-to detect blockages in the coronary arteries
 (vessels that supply oxygen and nutrients to the heart) and locate areas of the heart
 that are permanently damaged, perhaps by a previous heart attack. For this test, MRI
 pictures of the heart are taken before, during and after administration of dobutamine.
 Gadolinium may be injected during part of the study to brighten the images. An EKG will
 be used to monitor the heart during the procedure.

 -  Vasodilator MRI - The procedure and objectives of this test are the same as those
 described for dobutamine stress MRI, except that this study uses dipyridamole or
 adenosine. These drugs dilate blood vessels, causing increased blood flow to the heart.

 -  Plethysmography MRI - This test determines the presence and severity of narrowing in
 arteries that supply blood to the leg. Blockage of these vessels often causes pain while
 walking. This study will compare plethysmography MRI with venous occlusion
 plethysmography, an older method of measuring blood flow in the legs. For venous
 occlusion plethysmography, a large blood pressure cuff is placed around the upper leg
 and a strain gauge (thin elastic band) is placed around the calf. The pressure cuff is
 inflated very tightly for 5 minutes to block blood flow to the leg, and another pressure
 cuff over the ankle is also inflated. When the large cuff is deflated, blood rushes to
 the leg, a smaller cuff is inflated to a low pressure, and the strain gauge measures the
 maximum blood flow to the leg for 1 or 2 more minutes. This procedure is done once or
 twice outside the MRI scanner and once or twice inside the scanner. The scans are
 performed as described above for the dobutamine and vasodilator studies. The strain
 gauge is not used for plethysmography MRI the MRI pictures are used to measure flow.
The purpose of this protocol is to allow development and testing of new MRI techniques
 suitable for evaluating patients with cardiovascular disease. Since such technical
 development work often depends on preliminary studies in healthy volunteers, the protocol
 also recruits healthy subjects. This protocol will provide the framework for technical
 development scans in patients with cardiovascular disease.
-INCLUSION CRITERIA:

 1. Inclusion Criteria for All Arms of the Protocol:

 -  Subjects 18 years of age or older

 -  Written informed consent

 EXCLUSION CRITERIA:

 2. Exclusion Criteria for All Arms of the Protocol:

 -  Patients with a contraindication to MRI scanning will be excluded. These
 contraindications include patients with the following devices:

 -  Central nervous system aneurysm clips;

 -  Implanted neural stimulator;

 -  Implanted cardiac pacemaker or defibrillator;

 -  Cochlear implant;

 -  Ocular foreign body (e.g. metal shavings);

 -  Implanted Insulin pump;

 -  Metal shrapnel or bullet.

 3. In addition, the following patient groups will be excluded:

 -  Pregnant women (Patients who are uncertain as to whether they are pregnant will
 be required to have a screening urine or blood pregnancy test)

 -  Patients with active symptoms of myocardial ischemia occurring despite maximally
 tolerated doses of oral antianginal therapy and intravenous nitroglycerin

 4. Furthermore, the following patient groups will be excluded from studies involving the
 administration of MRI contrast agents:

 -  lactating women unless they are willing to discard breast milk for 24 hours after
 receiving gadolinium

 -  renal disease (estimated glomerular filtration rate (eGFR) less than 30
 ml/min/1.73 m(2) body surface area)

 The eGFR will be used to estimate renal function if reported by the laboratory, or as
 reported by NIH Clinical Center or Suburban Hospital or other clinically certified
 laboratories. Otherwise, estimated glomerular filtration rate (eGFR) can be based on
 the Modification of Diet in Renal Disease (MDRD) study equation (see below) in
 subjects with stable renal function. This formula is not applicable to patients with
 acute renal insufficiency:

 eGFR (ml/min/1.73 m(2)) equal to 175 times (serum creatinine)-1.154 times (age)-0.203
 times 0.742 (if the subject is female) times1.212 (if the subject is black)

 5. Additional Exclusion Criteria for Dobutamine, or Vasodilator Stress MRI:

 -  Myocardial infarction within 48 hours

 -  Uncontrolled congestive heart failure

 -  Severe hypertension (SBP greater than 200, DBP greater than 110) (exclusion only
 for dobutamine and bicycle)

 -  Atrial fibrillation. This exclusion only applies to Dobutamine stress.

 -  Frequent PVC s (more than 1 every 10 heart beats or non-sustained ventricular
 tachycardia (greater than 4 beat runs) or ongoing sustained ventricular
 tachycardia. This exclusion only applies to Dobutamine and Bicycle stress

 -  Patients with narrow angle glaucoma and known or suspected prostatic obstruction
 will not receive atropine

 6. Additional Exclusion Criteria for PET/MR perfusion scans

 -  Pregnant patients

 -  Patients that are breast feeding