Magnetic Resonance Imaging (MRI) uses a strong magnetic field and radio waves to create detailed images of the body’s internal structures. Because the machine operates on intense magnetic principles, metal near the scanner poses significant safety risks and interferes with image quality. Whether a wig can be worn depends entirely on if the hairpiece is completely non-ferromagnetic, meaning it contains absolutely no metal components. Even small, hidden pieces of metal can compromise safety and image integrity.
Why Wigs and MRI Machines Don’t Mix
The core issue stems from the MRI scanner’s superconducting magnet, which generates a field many thousands of times stronger than the Earth’s natural magnetic field. Ferromagnetic materials, such as iron, steel, and nickel, are violently attracted to this powerful static field. Any metallic object, including small clips or wires within a wig, could become a dangerous projectile, flying rapidly toward the center of the scanner bore. This projectile risk, often called the “missile effect,” is a major safety concern for both the patient and the equipment.
Metal objects can also absorb the radiofrequency (RF) energy transmitted by the MRI coils during the imaging sequence. This absorption causes the metal to heat up rapidly, creating a potential burn hazard on the patient’s skin or scalp. Even a tiny piece of metal, especially if shaped like a loop or wire, can concentrate enough RF energy to cause severe thermal injury.
Even if the metal is non-ferromagnetic or too small to cause a burn, its presence still degrades the quality of the diagnostic images. Magnetic susceptibility artifacts occur when the metal distorts the local magnetic field, appearing as large streaks and voids on the resulting scan. These artifacts can obscure the anatomy the doctor is trying to examine, potentially rendering the MRI procedure useless.
Identifying Hidden Metal Components
The most common culprits are the small, comb-like wig clips or pressure-sensitive fasteners used to secure the hairpiece. These clips are almost universally made of steel or another ferromagnetic alloy and are sewn into the wig cap’s perimeter. Patients should also inspect the underside of their wig for adjustable straps that utilize small metal buckles or hooks for sizing.
Certain synthetic or lower-quality wigs may contain a fine wire infrastructure to help maintain shape and volume, particularly around the hairline or crown. This internal wiring is often hidden and difficult to detect by sight alone. Furthermore, some older hair dyes or cosmetic glues used to attach the wig may contain trace amounts of metallic particles.
To determine if a wig is safe, a simple at-home test can be performed using a standard refrigerator magnet before the appointment. If the magnet visibly pulls, sticks to, or registers a slight attraction to any part of the wig, it must be left outside the MRI suite. This preliminary inspection helps patients avoid unnecessary delays and potential safety issues. The safest approach is to assume any pre-attached clip or fastener contains metal unless the manufacturer explicitly states otherwise.
Practical Steps and Alternatives for Your Scan
The most important preparatory step is to communicate openly with the MRI technologist or screening staff before the scan begins. Informing them about the wig immediately allows them to assess the risk and provide guidance specific to their facility’s protocols. They can also confirm if the specific type of scan, such as a head or neck MRI, necessitates the removal of all head coverings to ensure the magnetic field is unobstructed.
If the wig is deemed unsafe or must be removed for the best image quality, several non-metallic alternatives are available. A soft, non-metallic cotton or silk scarf can often be worn instead, provided it does not contain hidden hardware like pins or embellishments. Many facilities also provide a simple, disposable surgical cap, which is guaranteed to be entirely non-ferromagnetic and safe.
Facility staff understand the sensitivity surrounding head coverings and have procedures in place to protect patient privacy and personal belongings. Patients will be directed to a secure, private changing area to remove the wig and any other metal-containing items. These items are then stored safely outside the magnetic field. This ensures the patient’s comfort and dignity are respected throughout the preparation and scanning process.