Radiation and its usage in diagnostic medicine was essentially initiated in 1895, when a German scientist experimenting with vacuum tubes discovered the first X-ray apparatus. Called "X-ray" because the type of ray was unknown to Roentgen, the man who discovered it, it paved the way for many other types of diagnostic imaging utilizing radiation. Throughout the early 20th century, the X-ray was used during war to expose the existence of shrapnel and bullets in wounded soldiers' bodies. Today, it is used to detect injuries and two-dimensional problems, such as broken or fractured bones or pulmonary concerns. Also, X-raying a patient more greatly prevented the need for exploratory surgery, which, in times when antisepsis was not as prevalent as it is today, could prove dangerous and uncomfortable for the patient. Much time, pain, and greater stress on the patient has been eliminated with the use of the X-ray.