Which noninvasive imaging method provides structural detail of the brain without ionizing radiation?

• A. Angiography
• B. PET Scan
• C. EEG
• D. MRI

Answer: (D)

Structural imaging of the brain without ionizing radiation is best provided by MRI. MRI uses strong magnetic fields and radiofrequency pulses to produce high-resolution pictures of brain anatomy, clearly showing gray and white matter, cortical folds, and detailed structures without exposing you to X-ray–based radiation. This makes it ideal for assessing brain structure and identifying abnormalities like tumors, malformations, or demyelinating plaques.

Angiography involves X-rays and contrast to visualize blood vessels and can be invasive, with exposure to ionizing radiation. PET scans use radioactive tracers to map metabolic activity, which also involves radiation and focuses more on function than pure anatomy. EEG measures electrical activity and offers excellent temporal resolution, but it does not provide detailed structural images of the brain.