Magnetic Resonance Imaging

MRI works by placing the body in a strong magnetic field, which aligns the hydrogen atoms in the body's water molecules. Brief pulses of radio waves are then applied, causing those atoms to emit signals that vary depending on the type of tissue they are in. A computer translates these signals into highly detailed, three-dimensional images. Because MRI does not use ionizing radiation (unlike X-rays or CT scans), it is considered safe for repeated use and is preferred in situations where radiation exposure is a concern.

MRI is uniquely valuable for imaging soft tissues — including the brain and spinal cord, muscles, joints, abdominal organs, and breasts — because it produces far more contrast between different soft tissue types than X-ray-based imaging. In breast health, MRI is used when mammography and ultrasound need to be supplemented: it is recommended annually for high-risk women (including BRCA mutation carriers), used to assess the extent of disease before surgery, to evaluate response to neoadjuvant chemotherapy, and to investigate nipple discharge or other findings that standard imaging cannot fully characterize. A contrast agent (typically gadolinium, given intravenously) is often used in breast MRI to highlight areas of increased blood flow that may indicate cancer.

In neurology, MRI is the primary tool for diagnosing and monitoring multiple sclerosis, as it can detect the characteristic lesions (areas of demyelination) in the brain and spinal cord that define the disease. It is also essential in stroke evaluation, joint imaging, and detecting tumors in many parts of the body. The examination itself involves lying still inside a large, cylindrical magnet for 30 to 60 minutes; the machine makes loud knocking sounds during the scan, and some people find the enclosed space uncomfortable.

MRI is one of the most powerful diagnostic tools available, and for women at high risk of breast cancer, an annual breast MRI alongside mammography significantly improves detection compared to mammography alone. If you have a BRCA mutation, a strong family history, a history of chest radiation, or other high-risk factors, asking your provider whether breast MRI screening is appropriate for you is a worthwhile conversation.

For women with multiple sclerosis, MRI is not just a diagnostic tool — it is the primary way your neurologist monitors disease activity over time, even when you feel symptom-free. Understanding what your MRI results show, what 'new lesions' or 'stable disease' means in your specific case, and how those findings are influencing your treatment decisions helps you be an active participant in managing your condition. If you experience claustrophobia or anxiety about MRI scans, letting your provider know in advance is important — accommodations such as open MRI machines, anti-anxiety medication, or guided relaxation techniques can make the experience much more manageable.