Final answer:
In medical radiography, risk is carefully weighed against benefit by keeping diagnostic radiation doses low and using radiation only when necessary. Techniques have evolved to minimize exposure, while still providing detailed diagnostic information crucial for patient care.
Step-by-step explanation:
In medical radiography, the balance of risk versus benefit is critical in ensuring patient safety while obtaining diagnostic information. Diagnostic doses are kept as low as reasonably achievable, considering the tremendous benefits they provide in diagnosing various conditions. Radiation doses are carefully calculated, with procedures such as chest X-rays delivering as little as 0.1 mSv to targeted tissues, and sophisticated CT scans reaching around 10 mSv. It is important to note that doses from medical imaging, such as radiopharmaceuticals, typically range from 1 to 5 mSv, which are localized to specific tissues, apart from the special case of the thyroid scan using 131 I isotope, resulting in an exposure of about 0.75 Sv due to its longer half-life.
To minimize risk, imaging techniques have improved and faster films have been developed, and radiographers and patients alike are always mindful of the balance between the low risk of exposure and the high diagnostic value provided.