What is Radiology?
The branch of medicine concerned with the use of radiant energy (such as x-rays) in the diagnosis and treatment of disease.

What is a Radiologist?
A doctor who specializes in creating and interpreting pictures of areas inside the body. The pictures are produced with x-rays, sound waves, or other types of energy. A radialogist is trained in the diagnostic and/or therapeutic use of x-rays and radionuclides, and radiation physics; a diagnostic radiologist may also be trained in diagnostic ultrasound and magnetic resonance imaging and applicable physics.

Who was the first radiologist?
Radiology began in 1895 with Wilhelm Conrad Roentgen's discovery of the x-ray, a fuzzy, black and white picture.

Why is radiology important?
Radiology technology enables physicians to make accurate and early diagnoses, select the best treatment plans, and if the treatment involves surgery, even practice in advance. By using radiographic imaging and computers, surgeons can have a dress rehearsal. Three-dimensional images can be rotated; images can be manipulated to peel away organs and isolate a single structure - all on a computer screen. Today, 59% of the U.S. population receives imaging radiology service each year. Some of the most important and recent advances in medicine are occurring in neuroradiology. Interventional radiology is making minimally invasive surgery the option of choice. In it's first 100 years, radiology turned medicine upside down. In the next hundred years, radiology will turn medicine inside out!

Are we exposed to radiation in our everyday life?
Radiation is a natural part of life. Radiation is light, short radio waves, ultraviolet or x-rays. It has existed since the beginning of time and is an integral part of the universe in which we live. Life on earth has evolved in the presence of radiation. Radiation comes to us from many sources both natural and man-made. These sources include cosmic radiation from outer space, radiation from the soil and buildings, and natural isotopes in our own bodies. Cosmic radiation and terrestrial radiation vary with location.

How do you measure radiation?
There are a number of units to measure radiation dose and exposure:

rad or radiation absorbed dose
The amount of radiant energy absorbed in a certain amount of tissue.

rem or roentgen-equivalent-man
A unit of measurement that takes into account different biological responses to different kinds of radiation. The radiation quantity measured by the rem is called equivalent dose.

millirem
One thousandth of a rem, the unit for measuring equivalent dose.

roentgen (R, r) (rent-gen, rent-chen)
The international unit of exposure dose for x-rays or gamma rays. Roentgens are named after Professor Wilhelm Konrad Roentgen, the man who discovered x-rays in 1895.

sievert (Sv) (see-vert)
The unit for measuring ionizing radiation effective dose, which accounts for relative sensitivities of different tissues and organs exposed to radiation. The radiation quantity measured by the sievert is called effective dose.

millisievert (mSv) (mill-i-see-vert)
One thousandth of a sievert, the unit for measuring effective dose.

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