American Board of Internal Medicine (ABIM) Certification Practice Exam

Which imaging technique is most sensitive for detecting early inflammation in suspected spondyloarthritis?

1. CT scan

2. MRI

3. PET scan

4. X-ray

The correct answer is: MRI

MRI is the most sensitive imaging technique for detecting early inflammation in suspected spondyloarthritis. One of the primary reasons MRI is preferred is its ability to visualize changes in soft tissue structures and bone marrow edema, which are indicative of inflammatory processes. In spondyloarthritis, particularly in its early stages, these inflammatory changes may not be readily apparent on X-rays, which primarily capture bone changes rather than inflammation. Furthermore, MRI can detect sacroiliitis, a hallmark feature of spondyloarthritis, much earlier than traditional imaging modalities like CT or X-ray. While CT scans can provide detailed images of bone surfaces and may occasionally reveal changes, they do not assess soft tissue inflammation as effectively as MRI. PET scans, although useful in identifying areas of metabolic activity, are not typically used as a first-line imaging tool for spondyloarthritis diagnosis due to their higher cost and less availability. Therefore, MRI stands out as the optimal choice for early detection of inflammation associated with this condition.