Final answer:
The contrast differences observable in mammograms, often clearer in women with higher fatty tissue content in their breasts, are instrumental in distinguishing between benign and malignant tumors. Supplementary imaging methods like MRI are used to enhance mammogram detection accuracy and reduce false positives. Regular mammographic screening is advised for women over 50.
Step-by-step explanation:
The most reliable feature for determining benign vs. malignant lesions on mammography involves the evaluation of contrast differences due to varying tissue densities. Mammograms can provide evidence of a lump or region of increased density within the breast, which could be suggestive of cancer. However, since X-ray absorption by different soft tissues is similar, making contrasts challenging, additional imaging techniques such as MRI (Magnetic resonance imaging) may be used to supplement x-rays and improve the accuracy of detection.
Women with denser breasts, often younger women, may have less obvious contrasts, while older women, with more fatty tissue in the breast, typically present clearer contrasts against potential tumors in mammograms. Therefore, MRI has become a valuable tool to reduce false positives and provide a clearer image for diagnosis. Annual mammograms are generally recommended for women aged 50 and older as a routine screening to catch breast cancer early.