Final answer:
Brain imaging techniques such as CT scans, MRI, fMRI, PET scans, and ultrasound share features like non-invasiveness, the ability to visualize brain structures or functions, and the use of technology to detect tissue changes without direct access to brain tissue.
Step-by-step explanation:
Common characteristics among brain imaging techniques include the ability to visualize structures or functions of the brain, non-invasiveness, and the use of technology to detect changes in brain tissue. These techniques provide valuable insights into the brain's anatomy and physiology without requiring direct access to the brain tissue itself. CT scans, or computerized tomography, involve X-ray equipment to create detailed images of the brain, showing different degrees of tissue density. MRI, or magnetic resonance imaging, uses a strong magnetic field to generate signals from hydrogen atoms in the body, which are then translated into images. Its functional counterpart, fMRI, captures changes in brain activity over time by monitoring blood flow and oxygen levels, offering both anatomical and functional information. PET scans, or positron emission tomography, use radiopharmaceuticals to highlight areas of the brain with higher levels of activity, reflecting blood flow and metabolic processes. Lastly, ultrasound technology uses sound waves to generate images, typically used during pregnancies and is the least invasive method, posing no radiation exposure risks.