What is the purpose of a bone scan in medical diagnostics?

The purpose of a bone scan in medical diagnostics is to identify abnormal bone growth or abnormalities in the skeletal system. This imaging technique uses a small amount of radioactive material that targets areas of increased bone metabolism, which can indicate conditions such as infections, fractures, arthritis, or tumors. By highlighting these areas, a bone scan provides valuable insights into bone health and can help diagnose various orthopedic conditions.

The other options pertain to different diagnostic imaging techniques or assessments. For instance, measuring blood flow in the heart relates to cardiac imaging, which is typically done using methods like echocardiography, MRI, or PET scans. Analyzing brain activity usually involves techniques such as EEG or functional MRI, focusing on neurological function rather than bone health. Determining lung function is typically assessed through pulmonary function tests or imaging studies like chest X-rays or CT scans, which again do not pertain to examining bone structure. Therefore, the focus of a bone scan specifically on bone growth and abnormalities makes it the correct choice.