Meet The RMG Team

At RMG Medical Imaging Consultants, we know that to achieve desirable patient outcomes, we need to have an experienced and committed team at the helm.

You want high-quality service, premium images, and pleasant staff, but what you’re really looking for is a team to provide peace of mind.

We’ve taken great pains to assemble a qualified group of dedicated and compassionate providers to give the best service possible. We are committed to operate on the principle of responsive, patient-first care and building genuine, lasting relationships.

Edward Gabriel

Dr. Edward Gabriel, M.D., DABR

CEO, Managing Partner

With over 35 years of medical and leadership experience, Dr. Gabriel has been the CEO and managing partner of RMG since 2013.

Dr. Gabriel completed his undergraduate degree at UCLA and obtained his Medical Doctorate at Rosalind Franklin University/Chicago Medical School. Both his undergraduate and medical degrees emphasized digital applications in medicine and medical informatics. Dr. Gabriel completed his Residency and Fellowship training in Diagnostic Radiology from Loma Linda University/White Memorial Campus.

Upon completion of his Residency and Fellowship training, he joined RMG as a partner and outpatient medical director. He is a graduate of the USC Marshall School of Business’ Physician Leadership Program and has held medical director roles for both outpatient and inpatient radiology departments at Adventist Health White Memorial and Adventist Health Enterprise hospitals. Dr. Gabriel is currently the Chair of the Diagnostic Imaging Department at the White Memorial Medical Center. He continues to teach residents in all subspecialties including Diagnostic Radiology and has had the privilege to serve as the associate professor of radiology at Loma Linda University for over 20 years.

Carla K.

Carla Kefalas, CRA, R.T.(R)(M)(MR)(ARRT)

Director of Operations & Business Development

Carla is the newest member of RMG in her role as the director of operations and business development. Carla’s 20 years with Adventist Health in multiple roles, both clinically and as a member of the management team, pairs the administrative and clinical approach of RMG’s design. She has experience in the for-profit and not-for-profit health institutions as well as the complexities of a union environment.

Carla began her radiology journey graduating from Loma Linda University Radiologic Technology program in 1994 and extended her education with an emphasis in management. In the subsequent years, Carla has held multiple roles such as: lead mammography technologist, diagnostic imaging coordinator, supervisor, and operations manager. In 2015, she graduated from UCLA’s Healthcare Leadership and Management School of Public Health and successfully obtained her CRA (Certified Radiology Administrator) credential.

Her experience with Adventist Health, Providence, Comprehensive Imaging Partners of Orange County, and Long Beach Memorial Medical Center has established the skillset necessary to engage radiologists and hospital administrators to address the variable departmental needs and challenges that RMG supports.

Tony Nahas

Tony Nahas, B.S.

Strategic Advisor

Tony has been closely linked with RMG since 1993. He has extensive knowledge in the public and private sector regarding medical billing, contracting, tax laws, as well as state, local and federal regulations.

Tony graduated from Cal Poly Pomona in 1976 with a degree in Economics. His first 6 years began in the private sector. He then, catapulted his career for the next decade honing his skills as the director of accounts receivables for Adventist Health in the Southern California area.

In the last 20 years, Tony has played a pivotal role with RMG and the successful implementation of billing, compliance, payroll, and contract negotiations. He has evolved from business manager to director of business management to presently, strategic advisor where he will continue his instrumental contributions to RMG.

Ruth Johnston

Ruth Johnston

Senior Administrative Assistant & Credentialing Coordinator

For the past 19 years, Ruth Johnston has effectively represented RMG Medical Imaging Consultants. As the senior administrative assistant and credentialing coordinator, she works closely with over forty Radiologists and ten hospitals to ensure an efficient and effective partnership for RMG. She prepares and maintains practitioner credentialing files for approval by the Credentialing Leadership to comply with Medical Staff Offices, Joint Commission (“TJC”), American College of Radiology (“ACR”), policies & procedures, and regulatory agency requirements.

Southern California Physician Team

ct Us.

Edward Gabriel, M.D., DABR

  • President/Secretary, RMG
  • Department Chair/Medical Director, Adventist Health White Memorial
  • Regional Medical Director, Adventist Health/CVN
  • Regional Medical Director, Adventist Health/NorCal
  • Associate Professor of Radiology, Loma Linda University School of Medicine
  • General Radiology, Body Imaging, Nuclear Medicine, Mammography, PET/CT, Cardiac Imaging, Pediatric Radiology

Sean Johnston, M.D., Ph.D., DABR

  • Vice President, RMG
  • Surgical and Interventional Radiology, CT/MRI, General Radiology, US
  • Ph.D. in Immunology

Ruben Ricardo Brechner, M.D., Ph.D., DABR

  • Treasurer, RMG
  • General Radiology, Musculoskeletal, Nuclear Medicine, PET/CT, Mammography, CT/MRI, US
  • Ph.D. in Biomedical Engineering

Sameer Patel, M.D., DABR

  • Vice President, RMG
  • Medical Director, General and Vascular Ultrasound Department, Adventist Health White Memorial
  • General Radiology, Body Imaging, CT/MRI, Nuclear Medicine, Ultrasound

Arman Yaghoubian, M.D., DABR

  • Interventional and Vascular Radiology, CT/MRI, Nuclear Medicine

Jedediah Dixon, M.D., DABR

  • Interventional Radiology
  • Neuroradiology
  • General Radiology
  • Board Certified Internal Medicine

Linh Bui, M.D., DABR

  • General Radiology, Body Imaging, CT/MRI, US

 Elliot Kolin, M.D., DABR

  • Musculoskeletal Radiology, General Radiology, CT/MRI, US

Farnoosh Nooryani, M.D., DABR

  • Body Imaging, General Radiology, CT/MRI, Mammography, US, ABUS

Christopher Cumings, M.D., DABR

  • General Radiology, Mammography, Pediatric Radiology, Nuclear Medicine, ABUS

Central Valley Physician Team

ct Us.

Arthur Fontaine, M.D., DABR

  • Medical Director, Adventist Health/CVN Hospitals
  • Interventional Radiology
  • General Radiology, CT/MRI, Ultrasound

Marla Lander, M.D., DABR

  • Medical Director/Supervising Physician, Breast Imaging
  • Mammography, Breast US/ABUS, Breast MRI

Eric Hoffman, M.D., DABR

  • General Radiology, CT/MRI, ultrasound, nuclear medicine

Rahul Somani, M.D., DABR

  • Vascular/Interventional Radiology
  • General Radiology, CT/MRI, US

John Young, M.D., DABR

  • Vascular/Interventional Radiology

Stewart Souders, M.D.

  • Breast Imager
  • Mammography, Breast US/ABUS, Breast MRI

Nader Golian, M.D.

  • IR/Vascular Interventional, General Radiology, CT/MRI, US, Nuclear Medicine, Mammography

Northern California Physician Team

ct Us.

Geoffrey Horn, D.O., DABOR

  • Medical Director, Adventist Health Clear Lake
  • Medical Director, Adventist Health Mendocino Coast
  • Body Imaging, General Radiology, CT/MRI, Musculoskeletal, US, Nuclear Medicine, Mammography

William Gonser, M.D., DABR

  • Medical Director, Adventist Health Howard
  • Body Imaging, General Radiology, CT/MRI, US, Mammography

David Racker, M.D., DABR

  • IR/Vascular Interventional, General Radiology, CT/MRI, US, Nuclear Medicine, Mammography

William Duge, M.D., DABR

  • IR/Vascular Interventional, General Radiology, CT/MRI, Nuclear Medicine, Mammography

Laura Winkle, M.D., DABR

  • Medical Director, Adventist Health Ukiah Valley
  • Body Imaging, General Radiology, CT/MRI, US, Nuclear Medicine, Mammography

Rebecca Kuntz, M.D., DABR

  • Body Imaging, General Radiology, CT/MRI, Nuclear Medicine, US, Mammography

Henry Chen, M.D., DABR

  • Neuroradiology
  • Body Imaging, General Radiology, CT/MRI, US, Mammography

Madison McKenney, M.D., DABR

  • Body Imaging
  • General Radiology, CT/MRI, US, Nuclear Medicine, Mammography

Advanced Teleradiology (ATR) Night Team

ct Us.

David Jackson, M.D., DABR

  • Medical Director/President ATR
  • Neuroradiology, Emergency Radiology

Holly McCune, M.D.

Thomas Kelly, M.D.

Saif Siddiqi, M.D.

Patrick Browning, M.D.

Julia Lee, M.D.

Eileen Liljeblad, M.D.

Daniel Zee, M.D.

Kyaw Tun, D.O.

Senthill Gunasekaran, M.D.

Gerald Holta, M.D.

Asha Kavali, M.D.

Ben Lee, M.D.

John Vigilante, M.D.

William Glenn, M.D.

Peter Piampiano, M.D.

Michael Brand, M.D.

David Madwed, M.D.

Derek Grady, M.D.

Gholamreza Malek, M.D.

David Blood, M.D.

Frank Chen, M.D.

Kavi Devulapalli, M.D.

Bradley Hatfield, M.D.

Andrew Lee, M.D.

David Aufrichtig, M.D.


Questions? Contact Us.