Oftentimes, the man on the street does not know what radiology is; perhaps it's the study of radios. People may know what cardiology is, or ophthalmology or maybe microbiology. As a radiologist, I have the duty to explain what this word means.
Radiology is a branch of the art and science of Medicine pertaining with the use of ionizing (e.g., x and gamma rays) and non-ionizing (e.g., ultrasound) radiation, in the diagnosis and treatment of disease. Radio- obviously comes from radiation, that invisible energy out there. Previously this specialty was known as Röntgenology, in honor of Wilhelm Röntgen, the German physicist who discovered x rays back in 1895, for which he received a Nobel price. (Another name for x ray is Röntgen ray.)
One hundred ten years has elapsed since that time and now radiology is the fastest growing branch of medicine in the world. Among all specialties, it is also the most technology- and instrument-driven, reaping contributions from computer technology, electronics and communications and applied physics and chemistry. Because of this technological flowering, several braches or medicine want to get some of this treasure. One notable example of which that use ultrasound technology is OB-GYN. This practice is frowned upon by many of my colleagues in the field, but the fact is that all doctors are free to impinge on the other braches; we can't impose on others. For me, the only thing I request or wish on the non-radiologists doing radiology-related work is that the patient's welfare is paramount in their minds. The patient comes first. These doctors should be trained properly so that the radiologic reports are correct.
One thing I remember while still in training is that the cardiologists and urologists (e.g.) doing their fluoroscopic examinations didn't seem to know that x rays are used in the procedures. They continuously step on the pedal, instead of doing it sparingly or intermittently. You may 'fry' both the patient and the doctors, giving unreasonably large radiation doses. They don't seem to know the basics of radiation safety! I presume all radiology training institutions teach their residents the importance of radiation and instrument safety, not to mention the correct procedures in doing examinations, and the academic exposure to produce the best radiologists possible. I think radiology residency in the Philippines now requires 4 years to complete (from a previous 3). In like manner, all non-radiologists who use radiology in their practice should also be trained. This is not condescending on the others; safety should come first.
Nowadays radiology comprises a lot of different technologies or subspecialties: radiography (x rays as ordinary people are familiar), ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine (using radiopharmaceuticals), interventional (short of surgery), and a combination of all these. In the therapeutic side, we have radiation oncology (to give radiotherapy), including brachytherapy and giving isotopes; perhaps people are familiar with the gamma knife.
Doctors undecided in the specialty they wish to take should look in the direction of radiology... the final frontier.