How do I determine whether an MRI is necessary for a patient with suspected musculoskeletal disorders?

To determine whether magnetic resonance imaging (MRI) is necessary for a patient with suspected musculoskeletal disorders, consider the following key points:

• Suspected spinal metastases or metastatic spinal cord compression (MSCC): Offer an MRI scan urgently if there is clinical suspicion of MSCC, to be performed as soon as possible and within 24 hours at a local hospital with imaging facilities. For suspected spinal metastases without MSCC suspicion, offer MRI within 1 week to guide treatment options ¹.
• Myeloma suspicion: Offer imaging to all people with a plasma cell disorder suspected to be myeloma, with whole-body MRI considered as first-line imaging ².
• Neurological symptoms suggestive of multiple sclerosis (MS): MRI is part of the diagnostic process combined with history, examination, and laboratory findings, especially when neurological symptoms consistent with MS are present ³.
• Contraindications and alternatives: If MRI is contraindicated, consider CT scanning for suspected spinal metastases or MSCC ¹.
• Do not use plain X-rays to diagnose or rule out spinal metastases or MSCC as they are not appropriate for this purpose ¹.

In general, MRI is necessary when clinical features suggest serious underlying pathology such as spinal metastases, MSCC, myeloma-related bone disease, or neurological conditions like MS. The decision should be guided by clinical suspicion, urgency of diagnosis, and availability of imaging modalities.