Surgical sponges are not inherently visible on standard X-rays because cotton is radiolucent (transparent to X-rays). To prevent them from being left behind, modern surgical sponges are manufactured with a —usually a thin, blue strip made of barium sulfate.
: In long-term cases, the body may form a granuloma around the sponge, which can eventually calcify. Clinical Significance and Prevention Xray that includes sponges
: On an X-ray, this marker appears as a distinct, high-density linear or "ribbon-like" shadow. Surgical sponges are not inherently visible on standard