Final answer:
The general rule in diagnostic radiology is ensuring the benefits of the diagnosis outweigh the risks by using the lowest possible radiation dose, following the ALARA principle. Chest X-rays, CT scans, and radiopharmaceuticals are used judiciously with advancements in technology helping to reduce radiation doses.
Step-by-step explanation:
The general rule in diagnostic radiology is the utilization of the lowest radiation dose possible while achieving the required diagnostic quality. Radiation is employed only when necessary, to ensure the benefits outweigh the low risks associated with the procedure. The principle of As Low As Reasonably Achievable (ALARA) is followed to minimize exposure.
For example, a chest X-ray administers about 0.1 mSv to the affected tissue, which is generally low. Other procedures, like computed tomography (CT) scans, can administer up to about 10 mSv. In the use of radiopharmaceuticals for medical imaging, such as thyroid scans with iodine isotopes like 131I or 123I, care is taken to use isotopes that limit exposure to the patient, favoring those with shorter half-lives when possible.
Advancements in medical imaging technology and techniques, such as the use of faster films, have contributed to reducing the dosages of radiation. Moreover, sophisticated imaging like CT scans can now produce three-dimensional images or depict body function, offering greater diagnostic capability.