Which imaging technique is least likely to be used for bone assessment?

Ultrasound is least likely to be used for bone assessment due to its inherent limitations in visualizing dense structures like bones. While ultrasound is effective for assessing soft tissue structures, fluid collections, and guiding certain interventional procedures, it does not penetrate bone well. Consequently, it is not typically used as a primary diagnostic tool for evaluating bone conditions such as fractures, lesions, or osteoarthritis.

In contrast, imaging techniques like X-rays, CT scans, and MRI are specifically designed to assess bone integrity and pathology. X-rays are the standard initial imaging modality for evaluating most bone-related problems due to their ability to clearly depict bone structure. CT scans provide detailed, cross-sectional images of bones and are particularly useful for complex fractures or when assessing bone tumors. MRI is also valuable for evaluating bone marrow and surrounding soft tissues, making it a good choice for conditions that might involve both bone and soft tissue, such as infection or tumors.

Thus, given the specific function and limitations of ultrasound in bone assessment, it is the least suitable option compared to the other imaging techniques available.