A pattern of misinformation is circulating among hair salon professionals: Clients with sewn-in weft extensions are being told the extensions are safe for MRI because the attachment beads contain silicone. But this characterization isn't correct and has direct implications for patient safety and MRI screening accuracy.
Material composition of beaded weft foundations
Sewn-in weft extensions are not affixed by silicone alone. They rely on a beaded foundation, the composition of which varies by extension type. Common types include the following:
- Nano-bead extensions that use a metallic loop approximately 90% smaller than a traditional micro ring, typically made from copper or aluminum and designed for near-invisibility in fine hair.
- I-tip (also known as I-link) extensions, which consist of individual hair bundles with a plastic or metal tip threaded through a metal bead and clamped flat against the scalp, offering 360-degree movement.
- Flat-tip extensions, which are structurally similar to I-tips but which use a flattened tip for reduced profile against the scalp.
These microbeads are constructed with an inner silicone layer and an outer colored metallic layer, allowing them to be tightly crimped while blending in with the individual's hair color.¹ The silicone functions as an inner lining to protect the hair strand, while the outer shell is metal. Describing these devices as "silicone" to patients, without disclosing the metallic outer layer is inaccurate.
Kelly Brock
MRI hazard profile of common bead metals
In the MRI environment, metallic objects present two primary categories of risk: ferromagnetic attraction (projectile and displacement hazard) and radiofrequency (RF)-induced conductivity heating (thermal injury hazard). The two metals most-commonly used in hair extension beads -- copper and aluminum -- are highly conductive, nonferromagnetic metals. Their primary risk profile in MRI is thermal, not projectile.
The combination of synthetic hair extensions, hair sprays and gels, and overheating of metallic microbeads can potentially lead to burns by forming conductive loops, particularly when these objects are within the zone of radiofrequency excitation.¹ This risk is compounded when the imaging target is the head, neck, or cervical spine -- precisely the anatomical regions for which beaded extensions near the scalp are most relevant.
These metallic objects can also be made of various ferromagnetic materials, introducing the additional possibility of dislodgement.¹ The specific alloy composition of commercially-available hair extension beads is not standardized, and patients are generally not informed of the exact metallurgical makeup of their beads at the time of fitting.
A case example
A 33-year-old woman with chronic pain and claustrophobia required MRI under anesthesia to evaluate for cervical-spine metastasis of her leiomyosarcoma. Her MRI safety screening questionnaire revealed she had hair extensions attached via microbeads, but she was unaware whether these microbeads were metallic. A handheld screening magnet did not identify ferromagnetism, but a metal wand detector confirmed the objects were in fact metallic. Due to the quantity and configuration of the beads and the inability of the patient to remove them independently, x-ray imaging was required to characterize the objects prior to a risk determination. The patient was rescheduled and the extensions were removed by a hairdresser before the MRI could be safely performed.¹
Thermal events are the most commonly-reported serious injury in patients undergoing MRI, and metallic microbeads used for hair extensions represent an increasingly common trend that can potentially lead to such complications.¹ This case report, to the authors' knowledge, represents the first published report of a patient presenting with metallic hair extension microbeads for MRI.
Critically, the patient in this case did not know her beads were metallic. That information gap originated upstream -- at the point of installation.
Implications for MRI safety screening
Extensions that include metallic microbeads, rings, or clips should be removed before a scan. This includes I-tip extensions, microbead extensions, and volume weft with beads, including beaded rows, invisible wefts, and butterfly wefts.²
The MRI safety screening process depends on accurate patient self-reporting. When a patient is told by their stylist that their extensions are "just silicone," they have no basis to disclose a metal concern at intake. This creates a downstream failure in Zone II screening that is not the patient’s fault -- it is the result of inaccurate pre-procedural counseling.
Hair salon professionals are not MRI safety officers and are not expected to perform contraindication assessments. They are, however, capable of providing accurate material disclosures. The appropriate guidance to clients is straightforward: extensions contain metal beads. Before any MRI examination, patients should disclose this to the MRI technologist and specify the type of extensions and bead composition to the extent known.
References
1. Kapoor, R., Wang, J., Zavala, A. M., Truong, A. T., & Truong, D. T. (2022). Metallic microbeads for hair extensions: Hidden dangers for magnetic resonance imaging. Radiology Case Reports, 17(9), 3274–3276.
2. Doctored Locks. (May 8, 2025). Hair extensions and MRI scan images: Metallic microbeads.
Kelly Brock is a radiologic technologist and clinical supervisor of ambulatory imaging at Hackensack Meridian Health in Paramus, NJ.
The comments and observations expressed are those of the author and do not necessarily reflect the opinions of AuntMinnie.com.
