A Positron Emission Tomography (PET) scan is an imaging procedure that provides detailed pictures of organs and tissues in the body at a molecular level. It works by using a small, safe amount of a radioactive drug, called a tracer, to highlight areas of biological activity. Patients often have questions about preparation, especially concerning clothing, since the scan requires lying still inside a large machine. Understanding what to wear, and what to avoid, is important for ensuring the procedure is comfortable and the images are clear.
Why Clothing Restrictions Exist During PET Scans
The primary limitation on clothing during a PET scan relates to the presence of dense materials, particularly metal. Standard bras often contain metal underwires, adjusters, or clasps, which must be removed before imaging begins. This restriction prevents image distortions, known as artifacts.
When a PET scan is combined with a Computed Tomography (CT) scan—a common practice—metal components severely interfere with the CT portion of the imaging. The dense metal absorbs the X-rays, leading to bright streaks or shadows on the resulting image. These artifacts can obscure underlying tissue, potentially masking a finding or creating a false-positive area of concern.
The presence of metal can also interfere with the detection of the radiotracer by the PET scanner itself, though this effect is often more pronounced on the CT image. To ensure an accurate and reliable scan, all metallic items, including underwires, zippers, and snaps, must be removed from the scan field.
Acceptable Alternatives and Non-Metallic Options
Patients concerned about comfort or support have alternatives to a standard underwire bra. The most straightforward solution is wearing the hospital gown or scrubs provided by the facility, as these are guaranteed to be metal-free. If a patient prefers to wear their own clothing, it must be completely free of metal or other dense materials.
Acceptable garments include loose-fitting clothing like sweatpants, yoga pants, and t-shirts made from natural fabrics such as cotton or fleece. For upper-body support, a non-wire sports bra or a cotton camisole is usually permitted, provided it has no metallic clips, plastic components, or thick padding. Thick elastic or dense fabric can sometimes mimic tissue abnormalities on the scan, so comfort and simplicity are recommended.
General Preparation for Scan Day
Beyond specific clothing choices, successful PET scan preparation involves removing all accessories that could interfere with the imaging. Patients should leave all jewelry, including rings, necklaces, watches, and earrings, at home before arriving for the procedure. Hairpins, belt buckles, and removable dental work must also be taken off before entering the scanning room.
Patients should anticipate a potentially cool environment in the scanning room, as they will need to remain still for an extended period, often between 45 and 90 minutes. Maintaining stillness is important for image clarity, and comfort aids in this process. If a patient arrives wearing clothing with metal, they will be asked to change into a metal-free gown or scrubs provided by the facility before the injection of the radiotracer.