Computed Tomography (CT) is a diagnostic tool that uses specialized X-ray technology to create detailed cross-sectional images of the body. The scanner rotates around the patient, taking numerous images that a computer compiles into a three-dimensional view of internal structures. To obtain the clearest possible picture, medical facilities generally require patients to remove all external metal jewelry before the procedure. This protocol ensures the diagnostic quality of the images.
When a piercing is new, difficult to access, or impossible to remove, patients face a dilemma. Understanding the consequences of leaving metal in place during a scan is important for making an informed decision.
How Piercings Affect CT Scan Image Quality
Metal objects interfere with CT imaging because dense materials interact strongly with X-ray beams. The primary issue caused by metal jewelry is “metal artifact,” a distortion appearing on the final diagnostic image. This occurs because the dense metal completely absorbs or scatters the X-rays, preventing accurate data collection for that specific area.
The artifact typically manifests as bright, radiating streaks or dark shadows that fan out from the metal object, often called a “starburst” pattern. These streaks obscure the view of soft tissues and organs immediately surrounding the piercing site. For instance, a facial piercing can make a sinus or dental CT scan impossible to interpret, and a navel piercing can degrade abdominal wall image quality.
Significant artifact compromises the radiologist’s ability to accurately diagnose a condition, especially if the area of concern is near the piercing. An obscured image may be deemed non-diagnostic, necessitating a repeat procedure. While advanced software algorithms can partially reduce the severity of these artifacts, they cannot eliminate the distortion entirely.
Physical Risks of Wearing Metal During a Scan
Unlike Magnetic Resonance Imaging (MRI), which uses powerful magnetic fields, a standard diagnostic CT scan poses a very low physical risk from metal jewelry. The CT process relies on X-rays, which do not create the strong magnetic pull that can cause ferromagnetic metal objects to rapidly heat up or move violently. For a routine scan, the risk of a thermal burn caused by the CT machine itself is minimal.
A potential for localized heating may exist in certain highly specialized or interventional CT procedures, such as those that use CT-guided fluoroscopy where the X-ray beam is on for a longer, continuous duration. In these rare instances, highly conductive metal, especially large-gauge or closed-loop jewelry, could theoretically cause a minor localized thermal reaction. Any patient experiencing discomfort or warmth near the jewelry during the scan should immediately alert the technologist.
The main safety concern is less about the machine and more about the jewelry itself. Piercings that are loose or poorly secured could potentially move or fall out during the scan. The most significant consequence of leaving metal in remains the compromise to the medical image quality, rather than a direct threat to patient safety during a typical diagnostic CT.
Safe Alternatives When Piercings Cannot Be Removed
When a piercing is new or located in a difficult area, forcing its removal can lead to the piercing closing or causing trauma to the surrounding tissue. In these cases, the solution is to temporarily replace the metallic jewelry with a non-conductive, non-metallic retainer. These alternatives are designed to keep the piercing open while allowing the CT scanner to obtain clear images.
Medical-grade retainers are typically made from materials such as Polytetrafluoroethylene (PTFE), glass, or specific types of plastic, including Bioplast. These materials are radiolucent, meaning they are transparent to the X-rays used in the CT process and do not create the image-obscuring metal artifact. The small amount of artifact produced by these materials is generally negligible and does not interfere with diagnosis.
Patients should contact a professional piercer or the imaging facility ahead of their appointment to discuss inserting a non-metal retainer. This replacement must occur well before the scan to prevent irritation or swelling. If a non-metal alternative is not available, the patient must inform the CT technologist before the scan, allowing them to adjust the scanning protocols or consult with the ordering physician about postponing the scan or considering an alternative imaging modality.