The aim of this clinical study is to 1) establish a healthy database for nuclear perfusion imaging of the lower extremities and 2) assess the prognostic value of radiotracer-based perfusion imaging for predicting clinical outcomes in patients with peripheral artery disease (PAD) who are undergoing lower extremity revascularization procedures. We hypothesize that radiotracer imaging of the lower extremities will provide a sensitive non-invasive imaging tool for quantifying regional abnormalities in skeletal muscle perfusion and evaluating responses to medical treatment.

PAD patients (n=80) with peripheral artery disease (PAD) who are scheduled to undergo lower extremity revascularization procedures will be recruited. Patients will be screened using a standard medical history questionnaire and a physical activity questionnaire. Once their questionnaires are reviewed, individuals who meet inclusion criteria will proceed with standard PAD screening, which will include Ankle-Brachial Indices (ABIs) and Toe-Brachial Indices (TBIs) of both lower extremities. Patients will undergo SPECT/CT or PET/CT perfusion imaging prior to their revascularization procedure and 1-14 days following revascularization. Subjects will receive an intravenous injection of a standard clinical dose of radiotracer for both imaging sessions. A low-dose CT scan will be performed immediately after each SPECT and PET image acquisition for the purposes of attenuation correction and regional analysis of radiotracer uptake. Clinical outcomes will be evaluated for up to 12 months after the imaging study to assess the prognostic value of perfusion imaging for predicting subsequent outcomes. An additional subset of PAD patients (n=56) and healthy control subjects (n=56) will be enrolled to undergo the same imaging procedures to establish a healthy database for PET perfusion imaging measures.

Inclusion Criteria for Patients with Peripheral Artery Disease:

1. At least 18 years of age
2. Evidence of significant obstructive disease for one or multiple lower extremity arteries, as identified by prior ABI, TBI, CT angiography, ultrasound, or MR imaging.

Exclusion Criteria for Patients with Peripheral Artery Disease:

1. Unable to give informed consent or follow-up
2. Pregnant or nursing
3. Under the age of 18
4. No history of peripheral artery disease

Inclusion Criteria for Healthy Control Subjects:

1. At least 18 years of age
2. No evidence or prior diagnosis of peripheral artery disease based on chart review and standard vascular screening.

Exclusion Criteria for Healthy Control Subjects:

1. Unable to give informed consent of follow-up
2. Pregnant or nursing
3. Under the age of 18
4. History of peripheral artery disease