The overall goal of this study is to investigate the signal intensity and relaxation rate characteristics of gadoterate meglumine (Dotarem, Guerbet, USA) enhanced myocardium during rest and stress perfusion cardiovascular magnetic resonance (CMR) compared to gadobutrol (Gadavist) to prove that Dotarem provides constantly high myocardial relaxation necessary for accurate quantitative perfusion evaluation.

The purpose of this study is to compare two types of contrast that patients receive during cardiac MRI scans to visualize the blood flow in the cardiac muscle. Both contrasts are used in standard of care procedures, and the one administered for each patient will be randomly selected. The length of the MRI study all procedures are the same as the clinically indicated scan.

The overall goal of this study is to investigate the signal intensity and relaxation rate characteristics of gadoterate meglumine (Dotarem, Guerbet, USA) enhanced myocardium during rest and stress perfusion cardiovascular magnetic resonance (CMR) compared to gadobutrol (Gadavist) to prove that Dotarem provides constantly high myocardial relaxation necessary for accurate quantitative perfusion evaluation. Within this overall goal, the following specific aims will be pursued:

• Aim 1: To test the hypothesis that the signal intensity enhancement during Dotarem myocardial stress/rest perfusion is relatively constant, providing linear and stable enhancement in the myocardium, and is not inferior compared to gadobutrol (Gadavist).
• Aim 2: To test the hypothesis that the relaxation rate enhancement during Dotarem myocardial rest perfusion is uniform in the myocardium.

• Myocardial Perfusion Imaging
• Magnetic Resonance Imaging

• Group 1 - Dotarem
  Group 1 (n=30) will receive the clinically approved gadoterate meglumine (Dotarem, 0.1mmol/kg) as the contrast agent for their clinical perfusion study
• Group 2 - Gadavist
  Group 2 (n=30) will receive the clinically approved gadobutrol (Gadavist, 0.1mmol/kg) as the contrast agent.
  Intervention: Drug: Gadavist 15Ml Solution for Injection

Aim 1

Inclusion criteria:

To be eligible for the study: (All answers must be "YES" for subject to be eligible.)

1. Subject must be referred for a clinically indicated contrast-enhanced stress myocardial perfusion MRI scan out of concern of suspected myocardial ischemia.
2. Subject must be older than 18 years of age.
3. Subject must provide written informed consent prior to any study-related procedures being performed.
4. Subject must be willing to comply with all clinical study procedures.

Exclusion Criteria:

The presence of the following excludes subjects from the study: (All answers must be "NO" for subject to be eligible.)

1. Subject is a pregnant or nursing female. Exclude the possibility of pregnancy:

   • By testing (serum or urine beta HCG) within 24 hours before study date, or
   • By surgical sterilization, or
   • Post-menopausal, with minimum one (1) year history without menses.
2. Subject has an implanted cardiac pacemaker or implantable defibrillator.
3. Subject has a ferromagnetic vascular clip.
4. Subject has a neurostimulation system (e.g. TENS-Unit).
5. Subject has any type of cochlear implant.
6. Subject has ocular foreign body (e.g. metal shavings).
7. Subject carries any implanted device (e.g. insulin pump, drug infusion device).
8. Subject has shrapnel, bullet, or other type of metal fragments within the body.
9. Subject has an acute psychiatric disorder or is cognitively impaired.
10. Subject is using or is dependent on substances of abuse.
11. Subject is unwilling to comply with the requirements of the protocol.
12. Subject is in acute unstable condition.
13. Subject has an allergy against gadolinium based contrast agents or pharmaceutical stressors used in this study.
14. Subject has impaired renal function (creatinine > 1.5 mg/dl).
15. Subject presenting with acute coronary syndrome.
16. Positive cardiac enzymes positive troponin, CK-MB, or myosin
17. ST-elevations, new transient ST changes greater than 0.05mV or T- wave inversions with symptoms

Aim 2

Inclusion criteria:

To be eligible for the study: (All answers must be "YES" for subject to be eligible.)

1. Subject must be referred for a clinically indicated contrast-enhanced stress myocardial perfusion MRI scan out of concern of suspected myocardial ischemia.
2. Subject must be older than 18 years of age.
3. Subject must provide written informed consent prior to any study-related procedures being performed.
4. Subject must be willing to comply with all clinical study procedures.

Exclusion Criteria:

The presence of the following excludes subjects from the study: (All answers must be "NO" for subject to be eligible.)

1. Subject is a pregnant or nursing female. Exclude the possibility of pregnancy:

   • By testing (serum or urine beta HCG) within 24 hours before study date, or
   • By surgical sterilization, or
   • Post-menopausal, with minimum one (1) year history without menses.
2. Subject has an implanted cardiac pacemaker or implantable defibrillator.
3. Subject has a ferromagnetic vascular clip.
4. Subject has a neurostimulation system (e.g. TENS-Unit).
5. Subject has any type of cochlear implant.
6. Subject has ocular foreign body (e.g. metal shavings).
7. Subject carries any implanted device (e.g. insulin pump, drug infusion device).
8. Subject has shrapnel, bullet, or other type of metal fragments within the body.
9. Subject has an acute psychiatric disorder or is cognitively impaired.
10. Subject is using or is dependent on substances of abuse.
11. Subject is unwilling to comply with the requirements of the protocol.
12. Subject is in acute unstable condition.
13. Subject has an allergy against gadolinium based contrast agents used in this study.
14. Subject has impaired renal function (creatinine > 1.5 mg/dl).