Radiation Exposure and Image Quality in X-Ray Diagnostic Radiology : Physical Principles and Clinical Applications

X-ray diagnostic radiology is a major world-wide activi- All doses due to medical exposure for radiological purposes ex- cept radiotherapeutic procedures . . . shall be kept as low as rea- ty. In Europe approximately 250 million X-ray examina- sonably achievable consistent with obtaining the required diag- tions are performed annually, and in the United States of nostic information, taking into account economic and social fac- America a similar level of radiological activity is under- tors taken. This results in the fact that the largest contribution to radiation exposure to the population as a whole is This concept is known as the ALARA principle (as low as known to be from man-made radiation sources arising in reasonably achievable), the form of diagnostic X-rays (UNSCEAR 2000). It is also In Article 4, 2(a), the MED states that: known that exposures vary widely, due to differences in Member States shall promote the establishment and the use of X-ray techniques and the level of skill of the operator of diagnostic reference levels for radiodiagnostic examinations the equipment. Consequently radiation protection of the patient is a major aim in modern health policy. The two Diagnostic reference levels are defined in Article 2 of the basic principles of radiation protection of the patient as MED as: recommended by the International Commission on Ra- Dose levels in medical radiodiagnostic practices . . .