Feasibility Study of Dialysis Clinic Semi-Autonomous Ultrasound Scanning Using the Vexev Ultrasound Imaging System for Arteriovenous Fistula Mapping Examinations. The CANSCAN Trial.

Inclusion Criteria: 1. Referred to a study site for chronic renal replacement therapy OR referred to a study site for management of CKD. 2. Able to understand the procedures and requirements of the study and provide written informed consent and authorization for protected health information disclosure. 3. Greater than or equal to 21 years of age at the time of written informed consent. Exclusion Criteria: 1. Patients' unable to load arm into scanning bed (due to upper limb medical co-morbidities/injury). 2. Patient has evidence of open or incompletely healed wounds on both arms. Patients with open or incompletely healed wounds on a single arm are not excluded - if the ipsilateral arm is not able to be scanned - contralateral arm may be scanned. 3. Any acute or chronic condition that would limit the ability of the patient to participate in the study - in the opinion of the principal investigator. 4. Previous vascular/vascular access surgery on both upper limbs. Patients with previous vascular/vascular access surgery on a single arm are not excluded- contralateral arm may be scanned. \-