PS174. Technical Superiority and Clinical Excellence of Duplex Ultrsound Arterial Maping (DUAM) versus Magnetic Resonance Angiogram (MRA) as the Sole Imaging Modality in Bypass Surgery (BS) and Endovascular Revascularization (EVR) for Critical Lower Ischemia (CLI) Patients: A Six-Year Comparative Study in a Tertiary Referral Vascular Centre