Short-term Perfusion Angiography Pilot Study (SPA)

Inclusion Criteria: 1. Subject is ≥ 18 years of age. 2. Subject or their legally authorized representative understands the research nature of the study and is willing and capable of providing informed consent 3. Subject has appropriate femoral arterial access 4. Subject presents with a Rutherford classification of 4 to 6. 5. Planned DSA with endovascular intervention below the knee on one or both limbs. This may include patients who undergo: 1. Above the knee (ATK) and below the knee (BTK) intervention during the same procedure. 2. Only BTK intervention. 3. ATK intervention with staged future BTK intervention within 6 weeks of the initial procedure. Exclusion Criteria: 1. Subjects whose ATK intervention is limited to only the common femoral or iliac arteries 2. Subject is unwilling or unable to comply with the protocol including all follow-up visits 3. Subject with active atrial fibrillation at time of procedure 4. Critical limb ischemia due to acute arterial occlusion. 5. Subject with documented ejection fraction \< 40% and/or prolonged bradycardia (\< 60 beats per minute) 6. Inability to collect toe pressure on index limb from subject 7. Subjects with history of or known reaction or sensitivity to contrast agent that cannot be pre-medicated or any other condition that precludes an endovascular intervention and DSA 8. Female subject of childbearing potential who is pregnant (she must have negative pregnancy test within the 48 hours prior to enrollment), or plans a pregnancy during study period, 9. Subject life expectancy \< 3 months, 10. Subject is participating in a potentially confounding device or drug clinical trial that interferes with this study 11. Investigator considers subject to be a poor candidate for the study or believes that the patient may compromise the study, e.g., concomitant conditions (reasons will be documented) )