About ERA

Eastern Radiological Associates (ERA) is a professional partnership of board certified radiologists (doctors trained in medical imaging and image interpretation) who have been providing radiology professional services since 1970. Our mission is simple. Eastern Radiological Associates serves the patient and physician community of the region (Montana, Wyoming, and surrounding) by providing the highest quality diagnostic imaging and interventional services in a caring and compassionate atmosphere. Did you know? We are involved in the Yellowstone community… learn...

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Meet the Radiologists

Brian Christenson

Brian Christenson, MD

Brian Christenson is a board-certified radiologist. He is fellowship/ subspecialty trained in interventional radiology.

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Neurologic Imaging

Neuroradiology is a subspecialty of radiology, focusing on the diagnosis and characterization of abnormalities of the central and peripheral nervous system, spine, and head and neck. Neurologic imaging methods include computed tomography (CT) and magnetic resonance imaging (MRI). Ultrasound is used in limited circumstances, in particular in the pediatric population. Angiography is traditionally used for diagnosis of vascular abnormalities or diagnosis and characterization of masses or other lesions but is being replaced in many instances by CT...

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Uterine Fibroid Embolization


What is uterine fibroid embolization? Uterine fibroid embolization is a way to treat fibroids of the uterus without surgery. Fibroids are masses of fibrous muscle tissue in the uterine wall. These fibroids are often painful and cause heavy menstrual bleeding. How is uterine fibroid embolization done? In uterine fibroid embolization a small tube called a catheter is inserted in the groin area and guided to the blood vessels that deliver blood to the uterus. Once the catheter is in place, Dr. Christenson will infuse small particles into the vessel,...

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Positron Emission Tomography (PET)

PET scan

Positron Emission Tomography (PET) technology, often used in combination with CT imaging, uses a scanner and a small amount of radioactive glucose (sugar) which is injected into a patient’s vein to make detailed, computerized pictures of areas inside the body where the glucose is used. A PET-CT scan consists of 2 parts: first, a CT scan to pinpoint the location for the PET, and then the PET scan itself. During a PET scan, a ring of detectors picks up radiation signals from the patient’s body coming from previously injected radiopharmaceuticals....

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