This is a technical development study with the goal to develop 3D techniques for atherosclerosis plaque characterization. We hypothesize that 3D MRI is superior to 2D MRI in characterizing major plaque constituents that contribute to severe clinical events such as myocardial infarction or stroke. The major advantages of the 3D techniques to be developed will include high spatial resolution, reduced scan times, and optimized image contrast. The use of contrast injection is not needed with the new techniques, which is greatly beneficial for patients with advanced chronic kidney disease.This is not a funded clinical trial.

All participants will undergo the conventional MRI protocol and the new imaging protocol using our developed techniques. They may have either non-contrast scans or contrast-enhanced scans or both depending on the stage of development. The comparison results between the two protocols will be used to evaluate the performance of the new techniques and help optimization of specific technical aspects.

Inclusion Criteria:

• Healthy Volunteers: male or female ≥ 18 years of age with a BMI<30, with no history of cardiovascular disease
• Patients: Medically stable, male or female ≥ 18 years of age diagnosed with an atherosclerotic plaque in the carotid artery who have not undergone stenting of the carotid artery to be imaged.
• Ability to read and understand informed consent

Exclusion Criteria:

• Contraindications to MRI including mechanically, magnetically, or electrically activated implants, ferromagnetic implants and ferromagnetic foreign bodies, pregnancy.
• Inability to tolerate MRI secondary to an inability to lie supine or severe claustrophobia.
• Non-compliant with visit instructions, including inability to lie still, hold breath or follow procedure instructions
• Severe allergy to animal dander or animal-instigated asthma
• Specific to gadolinium-based contrast agents: Renal function test does not meet CSMC standard of care MRI contrast protocol requirements (GFR <45ml/min) or previous allergic reaction to gadolinium-based contrast agents.*

100 healthy volunteers and 40 patients with carotid artery disease will be recruited for this technical development study.