For further assessment of a suspected spinal compression fracture in a patient with significant back pain, which test is most appropriate?

In the context of assessing a suspected spinal compression fracture in a patient presenting with significant back pain, the most appropriate test is magnetic resonance imaging (MRI) of the spine. MRI is particularly beneficial for evaluating soft tissue structures, including the spinal cord, nerves, and surrounding tissues. It provides detailed images that can help identify not only the presence of a fracture but also potential complications such as hematomas, nerve impingement, and any underlying pathology such as tumors or infections that might contribute to the patient's symptoms.

In contrast, a CT scan can also reveal bone structures and fractures, but it does not provide as much detail about the soft tissues. A DEXA scan is primarily utilized for assessing bone density, which can help evaluate the risk for future fractures rather than diagnosing an acute one. A technetium-99m bone scan detects areas of increased bone metabolism, which can indicate stress fractures or other pathological conditions but lacks specificity for acute fractures and does not provide clear anatomical detail as an MRI would.

Thus, MRI is the most appropriate imaging modality for suspected spinal compression fractures to fully assess both the fracture and its potential implications on adjacent structures.