our doctors

Dr. Berg attended medical school at the University of Minnesota, graduating in 2001. He went on to complete a radiology residency and musculoskeletal radiology fellowship at the University of Nebraska Medical Center. Dr. Berg joined Radiologists of North Iowa in 2007.

Dr. Berg served as President of the Medical Staff in 2016 and 2017 and currently serves as chairman of the American College of Graduate Medical Education Committee, overseeing residencies in Family Practice, Internal Medicine, and Palliative Care, as well as fellowships in Cardiology and Interventional Cardiology. He won Family Practice Residency Teacher of the Year Award in 2010.

In addition to performing general radiology and mammography, Dr. Berg’s specialty area is musculoskeletal radiology. He is a member of Alpha Omega Alpha medical honor society, as well as the Society of Skeletal Radiology, the Radiologic Society of North America, and the American College of Radiology. He is certified as a clinical densitometrist through the International Society of Clinical Densitometrists.

Dr. Holthaus grew up on a farm near Decorah, Iowa. He attended the University of Northern Iowa where he graduated Summa Cum Laude with the Purple and Old Gold Award in Biology and the Biology Dean’s Student Award. He attended medical school at the University of Iowa where he received the Henry J. Prentiss Award for Medical Gross Anatomy, Medical Student Award in Pathology, and the Carl Gillies Award for Excellence in Radiology. He completed a transitional year residency at Gundersen-Lutheran in La Crosse, Wisconsin and his radiology residency training at Vanderbilt University Medical Center in Nashville, TN.

Dr. Holthaus joined Radiologists of North Iowa in 2006 and specializes in interventional radiology in addition to performing general radiology. He focuses on image-guided procedures such as arterial and venous interventions, spine procedures, biopsies, and hemodialysis maintenance. He received the Mercy Golden Stethoscope Award in 2011.

Dr. Holthaus is a member of the Alpha Omega Alpha medical honor society, the Society of Interventional Radiology, the American Roentgen Ray Society, the Radiological Society of North America, and the American College of Radiology.

Dr. Matthews obtained his undergraduate degree at Emory University, then attended medical school at the University of South Florida College of Medicine.

He completed a radiology residency at the Medical College of Georgia, then joined the United States Army, where he served from 1991 until his honorable discharge from the military in 1999.

Before moving to Mason City and joining Radiologists of North Iowa, he completed a musculoskeletal radiology fellowship at Case Western Reserve.

Dr. Matthews is a member of the International Society of Clinical Densitometrists as well as the Society of Skeletal Radiology. In addition to general radiology and mammography, his specialty areas are musculoskeletal radiology and bone densitometry.

Dr. Ocel completed his undergraduate education at the University of Minnesota's Twin Cities campus, then attended Mayo Medical School in Rochester Minnesota. He completed a Transitional Year Residency at Gundersen-Lutheran Hospital in LaCrosse Wisconsin, then returned to the Mayo School of Graduate Medical Education for his residency in Diagnostic Radiology. He stayed at Mayo for his fellowship in Neuroradiology, finishing in 2009.

In addition to neuroradiology, Dr. Ocel covers general radiology, basic procedures involving the spine, joints, and breast, women's imaging, and nuclear imaging. He is a member of the American College of Radiology, the American Roentgen Ray Society, the American Society of Neuroradiology, and the American Medical Association. He is certified by the American Board of Radiology.

Dr. Petree trained at the University of Nebraska Medical Center, where she attended medical school, performed one year of internal medicine residency, and completed her radiology residency.

Dr. Petree joined Radiologists of North Iowa in 2006. In addition to the performance of general radiology and mammography, her focus areas include ultrasound and cross-sectional imaging of the body, including the chest, abdomen, and pelvis.

Dr. Petree is a member of Alpha Omega Alpha medical honor society, the American Roentgen Ray Society, the Radiologic Society of North America, the American Association for Women in Radiology, and the American College of Radiology.

Dr. Petree trained at the University of Nebraska Medical Center, where he attended medical school, performed one year of internal medicine residency, completed his radiology residency, and performed a fellowship in magnetic resonance imaging (MRI).

Dr. Petree joined Radiologists of North Iowa in 2006. In addition to performing general radiology and mammography, his specialty areas are complex cross-sectional imaging including MRI and cardiac imaging. He also specializes in many image-guided procedures.

Dr. Petree is a member of the American College of Radiologists, the American Board of Radiology, and the American Roentgen Ray Society.

Dr. Shah grew up in Oklahoma City and attended University of Oklahoma for both undergraduate studies and medical school.

After an internship in pediatrics, he completed a radiology residency at the University of Texas in Houston and a two year neuroradiology fellowship at Massachusetts General Hospital in Boston.

Dr. Shah joined the Radiologists of North Iowa in 2017. In addition to general radiology, Dr. Shah specializes in neuroradiology, which involves imaging of the brain, head/neck, and spine.

Dr. Shah is a member of the Alpha Omega Alpha medical honor society, American College of Radiology, RSNA, American Society of Neuroradiology.

Dr. Smith attended medical school at the University of Iowa. He completed a one year transitional residency at Gundersen-Lutheran Hospital in Wisconsin, then completed his residency in radiology at the Mayo School of Graduate Education in Rochester, Minnesota. During this time, he served one year as chief resident in the radiology department.

Dr. Smith joined Radiologists of North Iowa in 2008. In addition to general radiology, his practice concentrates on breast imaging, including as mammography, ultrasound, and breast MRI.

Dr. Smith is a member of Alpha Omega Alpha medical honor society. He is currently the President of Radiologists of North Iowa.

Dr. Broadbent is the newest radiologist to join the Radiologists of North Iowa. He specializes in Interventional Radiology.

Dr. Broadbent completed his Bachelor of Arts at the University of North Iowa in 2010, majoring in biology. He attended Rocky Vista University College of Osteopathic Medicine, earning a Doctor of Osteopathic Medicine degree in 2015. He went on to complete an Internal Medicine year, Radiology residency, and Interventional Radiology fellowship at the University of Illinois College of Medicine in Peoria Illinois, finishing in 2021. Dr. Broadbent served as Chief Resident in Radiology in 2019-2020.

Dr. Broadbent was the Internal Medicine Preliminary Resident of the Year during his Internal Medicine training. he was awarded the 2019 Radiology Master of Sport National Champion Award for achieving the highest overall score on the national ABR Core Examination.

Dr. Broadbent is a member of the Radiologic Society of North America, the American Roentgen Ray Society, the Society of Interventional Radiology, the Society of Nuclear Medicine and Molecular Imaging, and the Society for Imaging Informatics in Medicine.

We are happy to welcome Dr. Broadbent to Radiologists of North Iowa.

Dr. Jackson Herzog grew up in Iowa Falls. He attended Northwestern University and obtained an undergraduate degree in biology.

He went on to graduate from Northwestern University Feinberg School of Medicine. He completed a diagnostic radiology residency in Cleveland at University Hospitals Cleveland Medical Center where he subsequently also completed a fellowship in Musculoskeletal Imaging.

While specializing in Musculoskeletal Imaging, Dr. Herzog enjoys interpreting a broad scope of radiologic studies including general radiology, mammography, neuroradiology, and cardiac MRI.

Dr. Dunlay grew up in Mason City Iowa. He completed his undergraduate studies at Creighton University and attended medical school at University of Iowa Carver College of Medicine.

He was named to the Alpha Omega Alpha medical honor society. His diagnostic radiology residency and Body Imaging and Intervention fellowship were both completed at the Mayo Clinic in Rochester, Minnesota.

He joined the Radiologists of North Iowa in 2023. His interprets all types of diagnostic radiology studies, with subspecialization in cardiac MRI, prostate MRI, breast MRI, and mammography.

Dr. Lucas grew up in Nora Springs, Iowa. He attended Wartburg College in Waverly Iowa. His medical training began at the University of Iowa College of Medicine in Iowa City, Iowa, and continued at the University of Arkansas, where he completed his residency in diagnostic radiology and a fellowship in neuroradiology.

Dr. Lucas has been a member of Radiologists of North Iowa since 1989. In addition to mammography and general radiology, his specialty area is neuroradiology.

Dr. Lucas is a member of the American Medical Association, the American Society of Neuroradiology, the American College of Radiology, the Iowa Medical Society, and the Radiologic Society of North America.

Dr. Swenson attended medical school at the Uniformed Services University of Health Sciences F. Edward Ebert School of Medicine in Bethesda, Maryland.

He completed his radiology residency at Tripler Army Medical Center in Honolulu, Hawaii. He served 16 years in the United States Army, moving to Mason City and joining Radiologists of North Iowa in 2002 after being honorably discharged.

Dr. Swenson’s specialty areas are breast imaging and biopsy.

He is a member of the Radiologic Society of North America, the Society of Breast Imaging, The American Roentgen Ray Society, the American College of Radiology, and the International Society of Clinical Densitometry.

Heather started her career in medical imaging in 2001 when she began her training in radiologic technology at Mercy/St. Luke’s School of Radiologic Technology in Cedar Rapids, Iowa. She graduated in 2003 and worked as a radiographer in Iowa, Minnesota, and Illinois. In 2013, Heather completed a Bachelor of Science in Radiation Science at the University of Iowa while simultaneously completing the Diagnostic Medical Sonography program. Registered in a number of ultrasound specialties including abdominal imaging, obstetrics and gynecology, breast imaging, pediatric sonography, and vascular imaging, she worked as a sonographer in Chicago at Ann & Robert H. Lurie Children’s Hospital and most recently at MercyOne North Iowa in Mason City. In December 2020 Heather completed a Master of Science in Radio-logic Sciences while attending the Radiologist Assistant program through Weber State University in Ogden, UT. While attending the program, Heather performed her clinical internship with the Radiologists of North Iowa.

Heather performs a number of image-guided procedures and exams including superficial biopsies, therapeutic and diagnostic joint injections, joint aspirations, epidural steroid injections, drainage tube management, central venous line placement, and a variety of fluoroscopic procedures. She is a member of the American Society of Radiologic Technologists as well as the Society of Radiology Physician Extenders.

Heather resides in Clear Lake with husband, daughter, and dog. She enjoys cycling, reading, and a good cup of coffee.

Parker grew up in Mason City, Iowa. He obtained his Bachelor of Arts degree at the University of Northern Iowa in 2015, majoring in movement and exercise science.

He completed radiologic technology training at Mercy One-North Iowa in 2017 and, upon graduation, worked as a technologist in the Mercy One interventional radiology department, where he earned his vascular interventional radiography certification.

In December 2023, Parker completed Radiologist Assistant training through Weber State University in Ogden, Utah, obtaining a Master of Science in Radiologic Sciences. Parker performed his clinical internship with the Radiologists of North Iowa in Mason City.

Parker performs a number of image-guided procedures and exams including superficial biopsies, therapeutic and diagnostic joint injections, joint aspirations, epidural steroid injections, drainage tube management, central venous line placement, and a variety of gastrointestinal and genitourinary fluoroscopic procedures.

In addition to minimally invasive procedures, his focus areas include bone densitometry and post processing of cross sectional cardiac imaging.