Which structure is seen on both ultrasound and mammography according to the material?

Which structure is seen on both ultrasound and mammography according to the material?

• A. Pectoralis muscle
• B. Lymph nodes
• C. Rib
• D. Ducts

Answer: (A)

The main idea is recognizing structures that appear on both ultrasound and mammography and understanding why they’re visible across modalities. The pectoralis muscle lies just behind the breast and forms the posterior boundary seen by both imaging methods. On ultrasound it appears as a distinct muscular layer with characteristic fibrous striations and a clear posterior margin beneath the breast tissue. On mammography, it shows up as the posterior chest-wall boundary, most evident on views that help outline the back edge of the breast. This makes it a reliable cross-modality landmark, which is why it’s the best pick. Lymph nodes aren’t consistently visualized on mammography, ribs are bone structures and not the typical cross-modality landmark, and ducts aren’t regularly seen as discrete structures on mammography.

The main idea is recognizing structures that appear on both ultrasound and mammography and understanding why they’re visible across modalities. The pectoralis muscle lies just behind the breast and forms the posterior boundary seen by both imaging methods. On ultrasound it appears as a distinct muscular layer with characteristic fibrous striations and a clear posterior margin beneath the breast tissue. On mammography, it shows up as the posterior chest-wall boundary, most evident on views that help outline the back edge of the breast. This makes it a reliable cross-modality landmark, which is why it’s the best pick. Lymph nodes aren’t consistently visualized on mammography, ribs are bone structures and not the typical cross-modality landmark, and ducts aren’t regularly seen as discrete structures on mammography.