The test is requested when a healthcare provider suspects that a patient may have a fungal bone infection, which can cause severe pain, inflammation, and difficulty moving the affected limb. Fungal bone infections can occur as a result of direct contamination of the bone, such as through an open fracture, or through spread from another site of infection. The test may also be ordered if a patient has a weakened immune system due to conditions such as HIV/AIDS, cancer, or diabetes.