January Lopez, M.D., Radiologist
Breast Care Expert, Radiologist
Director of Breast Imaging, Hoag Breast Center
Dr. January Lopez has been a member of the Hoag Breast Care Team since
2010 and is the Director of Breast Imaging at Hoag Breast Center. She
has been selected by the Orange County Medical Association as a "Physician
of Excellence" consecutive years since 2016 and was recognized as one
of the “Top Women in Healthcare” by Orange County Coast Magazine in 2019.
Dr. Lopez graduated Phi Beta Kappa, summa cum laude from UC Berkeley, and
received her medical degree from UCLA Medical School, where she served
as President of the Alpha Omega Alpha medical honor society, as well as
President of the UCLA student chapter of the American Medical Association.
Dr. Lopez’s commitment to radiology was recognized early on in her
medical career, when she was awarded the Leo G. Rigler Award in Radiological
Sciences for the Outstanding Graduating Medical Student. She subsequently
completed her internship in Internal Medicine at St. Mary Medical Center
in Long Beach, where she was named “Intern of the Year”. Dr.
Lopez then returned to UCLA to complete her residency, during which time
she served as Chief Resident, and was the recipient of the UCLA “Radiology
Resident of the Year” award.
Dr. Lopez has been dedicated to the field of breast imaging since 2003
with her involvement in the landmark American College of Radiology (ACRIN)
Digital Mammography (DMIST) Trial. Dr. Lopez specializes in breast imaging
and breast biopsy, and has authored several radiology manuscripts and
textbook chapters. Outside of Hoag, she gives back to the community in
her role as a board member on the Susan G. Komen Orange County Board of
Directors.
Jennifer Overstreet, M.D., Radiologist
Associate Director of Imaging
Dr. Jennifer Overstreet is a board certified radiologist practicing at
Hoag Breast Care Center since 2009. Dr. Overstreet earned both her Bachelor
and Master of Science degrees in biology at Stanford University before
earning her M.D. from the UCLA School of Medicine. Dr. Overstreet remained
at UCLA completing her residency in diagnostic radiology and fellowship
training in breast imaging where she specialized in mammography, ultrasound,
MRI, and image guided breast biopsy.
Dr. Overstreet has participated in several research projects in the field
of breast imaging including early studies aimed at identifying the potential
advantages of digital mammography. She is an active member of the American
College of Radiology and the Society of Breast Imaging.
Nicolas von dem Bussche, M.D., Radiologist
Dr. von dem Bussche graduated from the U.C. Berkeley Phi Beta Kappa, Magna
Cum Laude with a double major in Molecular and Cell Biology and German
Studies. During his time at Berkeley, he participated in a number of activities
including studying abroad, volunteering at clinics for the under-served,
and basic science research. He received the top prize among German Studies
graduates and was among the top 11 graduates in Molecular and Cell Biology.
At the U.C. San Francisco School of Medicine he was the student representative
at the Association of American Medical Colleges. He received many clerkship
honors, conducted published research on the origins of epilepsy, and participated
in curricular reform efforts. He was elected to the Alpha Omega Alpha
Medical Honor Society.
After an internship in internal medicine, he started his residency at
the U.C. San Diego. During his training he presented a number of award
winning exhibits at the national meeting of the Radiological Sciences
of North America and was elected Chief Resident in his third year. He
stayed in San Diego for fellowship training in abdominal imaging and breast
MRI, and during this year he also served as an attending breast imager
at the Moore’s Cancer Center in La Jolla, California.
Dr. von dem Bussche joined the Hoag Breast Center in 2006 and holds voluntary
academic appointments at U.C. Irvine and U.C. San Diego. He is married
and has three children. In addition to spending time with his family,
he enjoys reading, travel, photography, and baseball.
Yingding Xu, MD
Dr. Xu joined NHRA in 2019. He graduated with honor from California Institute
of Technology and completed his medical school training at Stanford University
School of Medicine. He was the recipient of the Resident Teaching Award
during his internship year at Kaiser Permanente Santa Clara. He then returned
to Stanford Hospital and Clinics for his radiology residency and fellowship
where he received the Roentgen Resident Research Award from RSNA and served
as the chief fellow of the musculoskeletal imaging fellowship. Dr. Xu
also completed fellowship-level training in breast imaging at Stanford
University.
Zaihleen S Keller, MD
Dr. Zaihleen Keller joined NHRA in 2019. She specializes in breast imaging
and interventions. Dr. Keller graduated with high honors from UC Berkeley
with a degree in Chemistry and was presented with the George C. Pimentel
award at graduation for excellence in research. She spent two years following
graduation working in research, including formulating treatments for rare
genetic diseases.
Dr. Keller received her medical degree at Chicago Medical School. She was
elected to the Alpha Omega Alpha Honor Medical Society (AOA) in her junior
year, and served as president of her chapter. She received several awards
at graduation, including the Dr. Martin Gecht Memorial Award for leadership,
and the CMS Dean’s Award for service.
Dr. Keller completed her radiology residency and fellowship at the University
of Southern California (USC). In 2017, she was named one of Pasadena Magazine’s
top doctors.
Ashley Lotfipour, M.D., Radiologist

Dr. Ashley Lotfipour joined NHRA in 2015. She graduated summa cum laude
from UC San Diego, and with Alpha Omega Alpha honors from UC Irvine School
of Medicine. Dr. Lotfipour was subsequently the valedictorian of her business
school class at Paul Merage School of Business at UC Irvine, graduating
with a Master’s degree in business administration. She received
the Marie Curie Fellowship for research from the European Union and completed
a fellowship in magnetic resonance physics at the University of Nottingham.
Dr. Lotfipour served as chief resident at UC Los Angeles during her radiology
residency, where she received the ACR’s Moorefield Economics and
Health Policy Fellowship. She also served as chief fellow during her breast
imaging fellowship training at UC Los Angeles.
Lauralyn Markle, M.D., Radiologist
Dr. Lauralyn Markle joined Hoag Breast Center in fall of 2014. She has
20 years of experience as a dedicated Breast Imager specializing in early
diagnosis with extensive experience with newer technologies including
Breast Tomosynthesis (3D Mammography) and whole breast ultrasound.
She previously practiced in South Orange County from 1994-2008 where she
served as Medical Director of Memorial Care Breast Center and Assistant
Clinical Professor of Radiology at UC Irvine before moving to Texas in 2008.
Dr. Markle has been lead investigator and authored several breast research
studies as well as having received several awards including Excellence
in Healthcare Award, ABC-Ch7 and Soroptimist International “Women
Helping Women” Award. She is a member of Society of Breast Imaging,
Radiologic Society of North America, American Society of Breast Disease
and National Consortium of Breast Centers.
Suneet Pramanik, M.D., Radiologist
Dr. Pramanik graduated from Stanford University, where he received a Howard
Hughes Medical Institute grant for his work in Molecular Biology. He went
on to medical school at UCLA, where he earned the Leo Rigler Award, given
to the most outstanding student in Radiology, and also received a prestigious
RSNA National Research grant for his work in Neuroradiology. He then joined
UCLA for his Radiology training, where he presented at numerous national
conferences and received the RSNA Cum Laude Award for his educational
presentations. Finally, he completed his fellowship training in Breast
Imaging at UCLA, where he gained extensive training in Digital Breast
Tomosynthesis.
Peggy Pugh, M.D., Radiologist

Dr. Peggy Pugh has been in private diagnostic radiology practice in Orange
County since 1991. She has devoted herself to Women’s Imaging, with
particular focus on breast health. As a dedicated breast-imaging specialist,
she performs individualized imaging for detection and diagnosis of breast
cancer as well as other benign breast conditions. Dr. Pugh believes that
taking the time to talk directly with her diagnostic patients and discuss
exam results immediately is extremely important. This provides an opportunity
to educate patients and empower women to take an active role in their
breast health decisions.
Dr. Pugh has lived in Southern California ever since she was transplanted
from the East Coast with her family as a teenager. She received a Bachelor
of Science degree with honors from Cal Poly Pomona. She was awarded her
medical degree from University of Southern California and completed her
Internship at Los Angeles County-USC hospital. She completed her residency
in Diagnostic Radiology at University of California, Irvine and served
as Chief Resident in her third year. She continued at UCI for her Fellowship
year focusing on Ultrasound and Magnetic Resonance Imaging. Dr. Pugh has
several professional affiliations including Diplomate, American Board
of Radiology and Society of Breast Imaging. Dr. Pugh and her husband have
made their home in Orange County for many years. They has two college
aged children and a collie named Tucker. She has many non-medical interests
including cultivating California native plants in her garden, baking and
creating colorful glass and tile mosaics.
Nina Woldenberg, M.D., Radiologist
Dr. Woldenberg graduated Phi Beta Kappa from the University of Wisconsin-Madison,
and with Alpha Omega Alpha honors from Case Western Reserve University
School of Medicine. During her UCLA residency, Dr. Woldenberg was elected
by her peers and faculty to serve as both junior chief resident as well
as chief resident. Following her residency, Dr. Woldenberg completed a
breast imaging fellowship at UCLA. During her fellowship, Dr. Woldenberg
served as a Clinical Instructor and was the recipient of the UCLA "Acute
Care Imaging Service Award."
Brian L. Dubin, MD
Dr. Brian L. Dubin graduated with honors from Northwestern University and
with Alpha Omega Alpha (AOA) honors from Northwestern University Feinberg
School of Medicine. He served as Chief Resident at UCLA during radiology
residency and was recognized for scoring highest in the country on the
national in-service examination. During his breast imaging fellowship
at UCLA, he served as a Clinical Instructor and Chief Fellow while conducting
research on artificial intelligence and breast MRI. Dr. Dubin has given
lectures to radiologists throughout the US, India and Japan and was awarded
a Certificate of Merit by the Radiological Society of North America.