Our Radiologists

Board-certified MSK radiologist with over 20 years of experience spanning private practice and teleradiology.

Focused on recruiting, retention, culture, and advancing the radiologist experience through physician-led leadership.

Dr. Gregory Hall practices as a general diagnostic teleradiologist for RP Matrix. Additionally, he serves as RP Matrix Pod President for the Midwest area. He is based in Hilton Head, South Carolina.

Dr. Hall has practiced teleradiology since he retired from the U.S. Navy in 2013. Prior to teleradiology, Dr. Hall served as the radiology department head at the Naval Medical Center at Camp Lejeune, North Carolina, and the radiology department head and director of clinical support services at the Expeditionary Medical Facility in Kuwait.

He earned his medical degree from Uniformed Services University in Bethesda, Maryland. He completed his pediatric internship at the Naval Medical Center of Portsmouth, Virginia, and his residency at the National Capital Consortium in Bethesda, Maryland.

Dr. Tony Maung is a neuroradiologist who currently serves as Vice President of Radiology Operations at Matrix (since January 2026). In this role, he focuses on optimizing clinical workflows, improving daily practice efficiency, and managing radiologist scheduling and performance. By bridging the gap between clinical excellence and operational logistics, Dr. Maung works to ensure seamless shift pacing and maximum productivity across the practice.

He also serves as a Mosaic local Matrix Clinical Lead, spearheading the integration of advanced technologies, including medical speech-to-text engines and Large Language Models (LLMs), to streamline radiology reporting and reduce administrative burden for clinicians.

Dr. Maung completed his medical degree followed by advanced residency training at Harbor-UCLA Medical Center, specializing in neuroradiology.

Dr. Cynthia Wallentin is a neuroradiologist who joined Matrix in 2020. She currently serves as Vice President of Practice Collaboration (since January 2026), a role focused on strengthening relationships with partner sites and enhancing collaboration across practices. In this capacity, she works closely with clinical and operational teams to support alignment, communication, and long-term partnership success.

She also serves as Associate Director of Peer Learning and is a member of the Radiology Partners National Quality and Safety Committee, with a focus on advancing quality initiatives and promoting a culture of continuous improvement.

Dr. Wallentin completed her medical degree at The Warren Alpert Medical School of Brown University, followed by residency training at Norwalk Hospital and fellowship training in neuroradiology at Beth Israel Deaconess Medical Center in Boston.