is a Clinical Professor of Radiology and Medicine at Columbia University. He earned an MS in Radiological Physics and a PhD in Experimental Physics. He is certified in Radiological Physics by the American Board of Radiology and licensed by New York State in Diagnostic Imaging, Radiation Therapy Physics, and Medical Health Physics. He is a past President of the Radiological and Medical Physics Society of New York, past Vice President of the Radiological Society of North America, a member of the Standards and Safety Committees of the Society for Interventional Radiology, and a member of editorial and review boards of several scientific journals. He received the Marvin M.D. Williams award from the American Association of Physicists in Medicine (AAPM) in 2017. He is a fellow of AAPM, the American College of Medical Physics, the American College of Radiology, the Society for Cardiovascular Angiography and Interventions, and the Society of Interventional Radiology. He currently serves on International Electrotechnical Commission working groups responsible for safety and performance standards for projection and interventional radiology. He has been a member of NCRP Council for more than a decade. He chaired scientific committees that produced NCRP Report No. 168, Radiation Dose Management for Fluoroscopically-Guided Interventional Medical Procedures and NCRP Statement No. 11, Outline of Administrative Policies for Quality Assurance and Peer Review of Tissue Reactions Associated with Fluoroscopically-Guided Interventions (2014). He has over 100 refereed publications in the areas of radiological imaging, radiological health, and related topics.