Radiological Associates of Sacramento Medical Group is one of the largest private radiology practices in Northern California. RAS provides a range of radiology services in the areas of diagnostic imaging, radiation oncology and nuclear medicine. It provides patients with services, including MRI, fluoroscopy, DEXA scan, pregnancy ultrasound, prostate seed implants, gamma knife radiosurgery, routine diagnostic x-rays and mammography diagnostic and screening. Founded in 1917, RAS also offers advanced services, including megavoltage radiation therapy, diagnostic ultrasound, lymphangiography, CT scanning, full service neuroradiology, catheter angiography and computerized nuclear medicine procedures including Positron Emission Tomography. The company operates more than 20 facilities throughout the greater Sacramento and northern California areas.