Current assessment of lower limb ischemia cannot reflect the location and degree of ischemia. Tissue perfusion assessment was used in the diagnosis and treatment of lower limb ischemia in this project, and the quantitative evaluation of ischemia degree was realized by using its advantages of quantitative analysis and perfusion imaging.

Inclusion Criteria:

• Subject has been diagnosed as PAOD by symptom and imaging;
• Subject intends to take endovascular treatment in PUMCH;
• Subjects without heavy stenosis in infrapopliteal artery (stenosis<30%), or with short length lesion(length≤5cm, stenosis≥30%);
• Age > 35 and < 80;
• Subject has been informed the study and has signed informed consent;

Exclusion Criteria:

• Subject with MRI contraindications or allergic to iodinated contrast medium;
• Subject underwent intervention therapy or angioplasty in target vessel within the last 3 months;
• Subject after stent implantation in superficial femoral artery;
• Subject with severe heart dysfunction, renal dysfunction, or cancer;

The study was conducted in PAOD patients aged 35 to 80 years with clinical symptoms such as claudication, resting pain, or ulceration, who were intended for endovascular treatment. Computed tomographic angiography disclosed the occlusive lesion in their target lesion. Subject with complex infrapopliteal lesions was excluded in order to reduce the influence of other variables.