Final answer:
When a breast lesion is seen only on breast ultrasonography, ultrasonography should be used to perform the biopsy.
Step-by-step explanation:
When a breast lesion is seen only on breast ultrasonography, the modality that should be used when performing a biopsy of the lesion is ultrasonography. Ultrasonography is a noninvasive imaging technique that uses high-frequency sound waves to generate real-time images of anatomy. It is the least invasive of all imaging techniques and is frequently used for biopsy guidance. By using ultrasonography, healthcare professionals can visualize the breast lesion in real-time and guide the biopsy needle accurately to the target area.