Radiology and Neuroradiology

Meet Our Team

Mark Bittles, M.D. Radiology

Dr. Bittles is an interventional radiologist at Johns Hopkins All Children’s Hospital. He joined the hospital staff in 2015. Dr. Bittles earned his medical degree at University of Tennessee College of Medicine and completed his radiology residency and an interventional radiology fellowship at University of Washington Medical Center. He completed a pediatric radiology fellowship at Vanderbilt University Medical Center.
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Jane Cook, D.O. Radiology

Dr. Cook specializes in pediatric radiology with a focus on PET/CT and musculoskeletal imaging at Johns Hopkins All Children’s Hospital. She joined the hospital staff in 2019.
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John Deveikis, M.D. Radiology

Dr. Deveikis specializes in interventional neuroradiology in the Johns Hopkins All Children’s Institute for Brain Protection Sciences. He previously worked for the hospital from 2010-2014 before four years as a professor of neurosurgery and radiology at the University of Alabama-Birmingham. He rejoined the medical staff in 2018. Dr. Deveikis is based on the Johns Hopkins All Children’s main campus in St. Petersburg but also has privileges at AdventHealth Tampa.
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Kimberly Fagen, M.D. Radiology

Dr. Fagen specializes in pediatric radiology at Johns Hopkins All Children’s. She joined the hospital staff in 2019. Dr. Fagen earned her medical degree from the Uniformed Services University of the Health Sciences in Bethesda, Maryland. She completed her internship at National Capital Consortium and residency in diagnostic radiology at Naval Medical Center San Diego. She completed a fellowship in pediatric radiology at Children’s National Medical Center.
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Christopher Francis, M.D. Radiology

Dr. Francis specializes in diagnostic and interventional radiology with a special interest in in pediatric interventional oncology at Johns Hopkins All Children’s Hospital. He joined the medical staff in 2018. He was previously a radiologist with Radiology Associates of St. Petersburg. Dr. Francis earned his medical degree from the University of Florida College of Medicine. He completed his internship in medicine, surgery and diagnostic radiology, a residency in diagnostic radiology and a fellowship in vascular interventional radiology at the University of South Florida Morsani College of Medicine.
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Christopher Keup, M.D. Radiology

Dr. Keup specializes in pediatric radiology at Johns Hopkins All Children’s Hospital. He joined the hospital staff in 2019. Dr. Keup also serves in the U.S. Army Reserve.  He is currently attached to the Army Medical Department Personnel Management Command in Forest Park, Georgia, and is a Lieutenant Colonel in the Medical Corps. Dr. Keup earned his medical degree from the University of Missouri in Columbia, Missouri. He completed an internship in internal medicine from the University of Missouri-Kansas City in Kansas City, Missouri, followed by a residency in diagnostic radiology from the University of Missouri-Kansas City and a fellowship in pediatric radiology from Children’s Mercy Hospital in Kansas City, Missouri.
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Jennifer Kucera, M.D. Radiology

Dr. Kucera is a pediatric radiologist at Johns Hopkins All Children’s Hospital, specializing in ultrasound, fetal MRI and musculoskeletal radiology. She joined hospital staff in 2014. She also is an assistant professor in the Johns Hopkins University School of Medicine and the University of South Florida College of Medicine. She serves as the residency site director for the USF radiology residency program.
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Joseph Potthast, M.D. Radiology

Dr. Potthast is chairman and medical director of the Division of Radiology at Johns Hopkins All Children’s Hospital. He joined the hospital staff in 2004 as a diagnostic neuroradiologist and pediatric interventional radiologist. He is also associate clinical professor of diagnostic radiology and neuroradiology for the University of South Florida College of Medicine. Dr. Potthast earned his medical degree at the University of South Florida College of Medicine. He completed an internship at the University of Maryland Hospital in Baltimore and his diagnostic radiology residency at the LSU Medical Center Hospital in Shreveport, Louisiana. He completed a fellowship in neuroradiology at the University of South Florida. 
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Javier Quintana, M.D. Radiology

Dr. Quintana is a radiologist at Johns Hopkins All Children’s Hospital. He joined hospital staff in 2010. Dr. Quintana earned his medical degree at the University of South Florida. He trained in general pediatrics at Jackson Memorial Hospital/University of Miami and completed a diagnostic radiology residency at Geisinger Medical Center in Danville, Pennsylvania. Dr. Quintana completed a pediatric radiology fellowship at Children’s Hospital of Philadelphia. He is fluent in Spanish.
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William Schaaf, M.D. Radiology

Dr. Schaaf is a graduate of the Drexel University College of Medicine (formerly Medical College of Pennsylvania Hahnemann School of Medicine). He completed his residency in diagnostic radiology at Eastern Virginia Medical School, Norfolk, VA, where he served as chief resident. He also completed his pediatric radiology fellowship at Cincinnati Children’s Hospital Medical Center. Dr. Schaaf is board-certified in radiology and board-admissible in pediatric radiology.
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