Bone mineral densitometry (BMD) is a diagnostic method that determines the presence of osteoporosis based on numerical values. However, the images acquired during BMD can provide additional valuable information about the patient beyond bone density, so careful attention to image interpretation is essential. We report a case involving a 47-year-old woman with a history of breast cancer, in whom an abnormal lesion in the left femur was incidentally identified during a BMD scan. Subsequent PET/CT and bone scintigraphy confirmed bone metastasis. This case highlights the importance of image interpretation during BMD examinations. During a BMD examination, radiologic technologists should provide relevant information to the attending physician—and to the patient if necessary—when abnormalities are detected in the imaging data, in order to support accurate diagnosis and appropriate treatment.