Amputation Arm

In an ex vivo human cadaveric model, post-PVI histopathologic analysis will be used to uncover the impact of plaque type on device safety (POBA versus atherectomy) and performance, facilitating evidence-based device selection to mitigate complications. Using a randomized approach, the investigator will compare plain balloon angioplasty to orbital atherectomy prior to angioplasty in amputated legs from PAD patients with plaques characterized into 4 categories based their MRI-histology: concentric calcium, eccentric calcium, fibrous plaque, and soft plaques (smooth muscle and thrombus).

Revascularization Arm

Patient Imaging Protocol: Scans will be performed on 100 patients enrolled into the study population using a 3T MAGNETOM scanner (Siemens) at the Houston Methodist Research Institute Translational Imaging Center. The investigator will use pre-operative images captured using the optimized MRI-histology sequences to score lesions. Physicians performing PVI will be blinded to the pre-operative MRI-histology images and anatomic scores and will make treatment decisions based on their standard of care. The investigator expect MRI-histology plaque scores predict which patients will have PVI failures due to untraversable plaque, and it may also foresee the potential need of adjunctive devices or alternative approaches for successful PVI