Which imaging modality is typically used as the initial study in suspected CRPS to identify soft tissue swelling and regional osteopenia?

• A. X-ray
• B. CT
• C. MRI
• D. Ultrasound

Answer: (A)

When CRPS is suspected, you want an imaging test that quickly screens for obvious bone injury and can show early soft tissue changes. A plain X-ray fits that role best as the initial study. It’s readily available, inexpensive, and fast, and it helps rule out fractures or other acute bone problems that could mimic CRPS. In the early phases, X-rays may reveal regional osteopenia and soft tissue swelling, which, while not specific to CRPS, can support the diagnosis and guide further workup. If X-ray findings are inconclusive, more sensitive imaging like MRI (which shows soft tissue edema and bone marrow changes) or bone scintigraphy can be pursued, but they are typically not the first step.