This project is designed to demonstrate equivalence of Dotarem enhanced LGE-CMR (late gadolinium enhancement cardiac MRI) with Gadoviost enhanced LGE-CMR from the standpoint of visual image quality, quantitative image quality, and association with clinical outcomes.

Gadolinium-containing contrast agents (GdCAs) are intravenous agents used for contrast enhancement with magnetic resonance imaging (MRI) and with magnetic resonance angiography (MRA). The GdCAs (gadodiamide, gadopentetic acid, gadobenic acid, gadoxetic acid, gadoteridol, gadobutrol and gadoteric acid) have been in use for few decades for different types of MR scan varying from product to product, including liver, brain, and whole body scan.

Recently, there has been a great interest in employing contrast-related techniques to assess for fibrosis in the myocardium of the heart. As opposed to nuclear methods, viability assessment by MRI is a nonstress examination that provides high-resolution detail, including functional assessment of the left ventricle in approximately 30 minutes. Assessment of myocardial viability is performed using 5- to 20-minute delayed, gadolinium-enhanced MRI. On delayed MRI, there is a relatively decreased washout of the gadolinium contrast agent in areas of myocardium that have been replaced by fibrosis or scar. In normal viable myocardium, the gadolinium contrast agent washes out more rapidly than it does from the fibrosis or scar. Since the difference between normal and abnormal myocardium is based on washout kinetics, images that are delayed by 5 to 20 minutes after contrast injection will optimally depict the fibrosis or scar.

The differences in gadolinium enhancement on MRI of viable myocardium and fibrosis or scar have been known for many years. Recently, however, MRI pulse sequences have been developed that greatly improve the conspicuity of the enhanced areas of myocardium that have been replaced by fibrosis or scar. The pulse sequence used is an inversion-recovery prepared gradient-echo sequence. In this method, an inversion pulse is used to null the signal from normal myocardium. Myocardium that is replaced by fibrosis or scar retains gadolinium and shows very high signal intensity compared with the suppressed, darker myocardium.

Gadovist has been the standard gadolinium contrasts used in the U.S. in CMR imaging for the past few years. On the other hand, Dotarem, a widely used contrast agent in Europe, has been introduced to be used in the U.S. market.The sensitivity of Dotarem to that of Magnevist in determining the location and extent of scar in patients scanned with CMR will be Gadovist in this study.

The CMR laboratory at the Houston Methodist DeBakey Heart & Vascular Center is one of the largest dedicated CMR laboratories in the U.S. performing 3,000 clinical CMR procedures per year. The laboratory has been in existence since 2008 and is currently equipped with 2 dedicated MRI scanners: 1.5T Siemens Avanto and 3.0T Siemens Verio. Through a research agreement with Siemens Medical Solutions, the laboratory has access to numerous works-in progress sequences as they are developed. The laboratory is equipped with an MRI compatible patient monitoring system, infusion pump, and power injector and is staffed by a team of 5 dedicated CMR technologists, 2 clinical nurses, 1 CMR fellow, an MRI scientist, and 2 attending cardiologists.

One hundred twenty patients with known or suspected cardiovascular disease will be recruited for this study. Patients will be randomized (in a 1:1 fashion) to receive either Dotarem or Gadovist for LGE-CMR such that there will be 60 patients in the Dotarem cohort and 60 patients in the Gadovist cohort.

Inclusion Criteria:

• Patients undergoing clinically referred CMR.

Exclusion Criteria:

1. Patients who are unable to give informed consent.
2. Individuals with severe claustrophobia.
3. Individuals unable to lie flat for 90 minutes (the anticipated amount of time to complete the MRI procedure).
4. Individuals who are pregnant.
5. Patients with implants or pacemakers.
6. Patients that have hypersensitivity to components of gadolinium.
7. Patients with renal failure.
8. Patients who had any trauma or surgery which may have left ferromagnetic material in the body.

Blinded reader of scans will not know whether subject received Dotarem or Gadovist.