What is the fine-grained topic of the following text: Dr. Yousaf provides dental x-rays for the residents of Stafford, Quantico Base, Manassas, Woodbridge, Fredericksburg, Spotsylvania, Garrisonville, and Roseville, VA.
series of x­rays is equal to the amount a person receives in a single day from natural sources. Only return the topic.
Dr. Yousaf providing dental x-rays for various locations in Virginia