Chronic pain is a leading cause of disability worldwide, yet current treatments often provide only modest and short-lived relief, frequently accompanied by side effects. Chronic pain is also highly individual: different patients show distinct patterns of brain activity when their pain fluctuates, suggesting that a one-size-fits-all approach to neuromodulation is unlikely to work well for most people. This project aims to develop and test a personalised, non-invasive neuromodulation strategy for chronic low back pain using advanced MRI and focused ultrasound (FUS). Patients will undergo several functional MRI sessions while continuously rating the intensity of their natural, ongoing pain. These data will be used to identify the brain regions in each person where activity most closely tracks their own pain experience. In a subsequent intervention phase, FUS will be applied in three conditions: targeting each patient’s personalised pain-encoding region, targeting a common group-level region, and a sham control. Pain ratings and MRI measures of brain activity and connectivity will be collected before and after each FUS intervention to assess both clinical and neurophysiological effects. This study will determine whether individually targeted FUS can provide greater pain relief than conventional group-based targeting. By linking individual pain signatures to tailored neuromodulation, the project aims to lay the groundwork for future clinical trials of safer, more effective, and truly personalised treatments for chronic pain.