The aim of this study is to establish a clinically feasible simultaneous evaluation of heart and lower limb using MRI and to assess the combined benefit of clinical and cardiac MRI imaging markers in the evaluation of PAD and prediction of treatment outcome.

We expect to enroll about 60 long-term DM patients (>10 years) from main study. Patient will receive evaluation of the perfusion in the lower limb by using blood oxygenation-level dependent (BOLD) sequence with measurement of the extracellular volume fraction (ECV) as an indicator of fibrosis severity in calf muscles. All patients will receive cardiac MRI (cardiac function, ischemia and fibrosis) and MR angiography (severity of PAD). The baseline studies will be completed within 2 years and 3 additional follow-up studies will be performed by the end of 4th year.

The inclusion criteria include:

1. Able to understand and provide signed informed consent
2. DM history of 10 years and above
3. Willing to receive 3 MRI follow-up and serum hematocrit examinations within 2 years, if applicable
4. Willing to receive standard therapy such as surgery or medication
5. Age between 18-80 years old

The exclusion criteria include:

1. Pregnant or breast-feeding women
2. Allergic MRI contrast medium
3. Absolute contraindications to contrast MRI (e.g., metallic hazards, hemodynamic instability, pregnancy, known allergy to contrast medium).
4. Contraindicated to MRI study: cardiac pacemaker, cochlear implantation, metallic object within eyeball
5. Patients that refuse to, or has poor ability of understanding and comply study conditions, such as severe dementia or difficulty in mobility
6. Patients having dialysis

We have to see if this corresponds to the IRB regulation.