Medical Imaging Grand Rounds

Wed, 06/21/2017 - 12:00pm

Presenter: Andrew Karellas, PhD, DABR, FAAPM, FACR

Title: The Benefits of Using Automated Patient Dose Monitoring Systems in Computed Tomography (CT) 

The Department of Medical Imaging is pleased to have Andrew Karellas, PhD, DABR, FAAPM, FACR, presenting at our Grand Rounds on Wednesday, June 21st, in the College of Medicine, Room 2117, at 12:00 pm.

Dr. Karellas received his PhD from UCLA in Medical Physics. He has been Professor of Hematology and Oncology at the Winship Cancer Institute of Emory University, Professor of Biomedical Engineering at the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Acting Vice-Chair for Research, Department of Radiology, Emory University School of Medicine.

Dr. Karellas has also received numerous honors and awards. He is a Fellow of the American College of Radiology (2012), a Fellow of the American Association of Physicists in Medicine (2001) and a member of Sigma Xi (1984. He has been a Reviewer “with Distinction” for Radiology Journal for 2009, he’s received a Dedicated Service Recognition Award as a Deputy Editor for Medical Physics, a Lifetime Achievement Award from Update New York Association of Physicists in Medicine and a Lifetime Service Award from the American Board of Radiology and he was elected as a “SPIE Senior Member” who has become distinguished through significant contributions in …, active involvement in…, service to the general optics and photonics community and contributions in relevant technologies.


Control of the radiation dose imparted to patients in medical imaging procedures is essential for maintaining image quality and for minimizing the probability of any radiogenic effects.  Radiation control is especially important in computed tomography (CT) because this procedure contributes the highest radiation dose to the general population in the United States compared to all other x-ray or nuclear imaging procedures.  Patient dose surveys have been published over the years but systematic personalized radiation dose monitoring for of patients undergoing CT and other x-ray imaging procedures is relatively new in medical imaging.  Recent requirements for patient dose monitoring are a positive development.  However, certain radiation metrics in CT such as CTDI, CTDIw, CTDIvol, exposure, dose, and effective dose used in this process are often misunderstood and this impedes effective communication of important quantities and assessment of radiogenic risk.    

This presentation will clarify the main concepts relating to radiation measurement and reporting in CT including the process and challenges in radiation dose measurements, CT dose output and personalized automated dose reporting.  The relationship between various dose metrics such as CTDIvol, Dose Length Product (DLP) and effective dose will be explained, and most importantly, emphasis will be given on what terms we should avoid using in reference to radiation dose in CT.  Radiation dose data and typical trends from automated radiation dose monitoring in CT will be presented.   Automated monitoring of radiation dose data can be very revealing of important trends, and it is a powerful tool for improving and maintaining good practice in CT.          


Andrew Karellas, PhD, DABR, FAAPM, FACR
Event Location: 

College of Medicine, Room 2117