Medical illustration is one well known human anatomy textbook that showcases a variety of anatomy depiction techniques. In 1895, Konrad Roentgen, a German physicist discovered the X-Ray. Internal imaging became a reality after the invention of the X-Ray. Since then internal imaging has progressed to include ultrasonic, CT, and MRI imaging. As a profession, medical illustration has a more recent history. In the late 1890s, Max Brödel, a talented artist from Leipzig, was brought to The Johns Hopkins School of Medicine in Baltimore to illustrate for Harvey Cushing, William Halsted, Howard Kelly, and other notable clinicians. In addition to being an extraordinary
Roentgen equivalent man sievert in 1980, but never accepted the use of the rem. The US National Institute of Standards and Technology (NIST) recognizes that this unit is outside the SI, but temporarily accepts its use in the US with the SI. The rem remains in widespread use as an industry standard in the US. The United States Nuclear Regulatory Commission still permits the use of the units curie, rad and rem alongside SI units. The following table shows radiation quantities in SI and non-SI units: Roentgen equivalent man The roentgen equivalent man (or rem) is an older, CGS unit of equivalent dose,