Radiation dose optimisation in biomedical imaging and intervention

Situations in life are never simply black and white. There are many shades of gray. The gray zones provide a lot of playing ground for scientists engaged in optimisation. We all understand what is meant by optimisation, such as " the procedure or procedures used to make a system or design as effective or as functional as possible " or " making the best of anything ". Thus, the driving force is getting to the " best ". For example, in medical imaging, one attempts to choose certain parameters to optimise, such as image quality and patient dose. Both do not go in the same direction. If one increases image quality (which is desirable), one ends up increasing patient dose too (which is not desirable). For radiologists, image quality is the main focus. How often does one hear a radiologist asking, while reporting an imaging investigation, " how much radiation dose has been imparted to the patient " ? Similarly, physicists are concerned with radiation dose. It is again not common to see a physicist asking himself what image quality is associated with the dose he estimated in an imaging procedure. Optimisation, therefore, tends to imply the best image quality for a radiologist and the least radiation dose for a physicist. Neither is desirable without regard for the other. Thus, the dictionary meaning of " optimisation " , in particular " making the best of anything " is not meaningful in isolation. The best may be happening in both but what we want to achieve works in opposite directions for the two parameters. To make things simpler, it is somewhat similar to the quality of consumer goods that we buy and the price that we have to pay. Higher quality involves higher price but we want to create a balance between quality and affordable cost. In this special thematic issue of Biomedical Imaging and Intervention Journal (BIIJ), 12 papers contributed by authors from 11 countries have reviewed the situation in conventional and digital radiography, fluoroscopy, mammography, PET/CT, computed tomography and radiotherapy. Educational issues for cardiologist on radiation protection and accident prevention in radiotherapy, both of which have important role in optimisation, have also been covered. A good quality assurance (QA) program should reduce the need for monitoring. This has been documented by Vano and Fernandez in their paper on dose management in digital radiography. They present the experience on an …