This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Why is the sensitivity of Mammography low in young females? 
Select and explain. 
A. Because of less glandular tissue and more fat, B. Because of less fat content, C. Young breast have dense tissue, D. Young females are less cooperative
C: Young breast have dense tissue
Answer: C: Young breast have dense tissue 
Explanation: Currently mammography is the principal screening modality for breast cancer. It has low sensitivity in breasts with considerable fibroglandular tissue paicularly in young women and in those on hormone replacement therapy. Digital mammography is useful in imaging dense breast tissue. Mammography has a sensitivity of 90% and specificity of 94%. The commonest mammographic abnormality of DCIS is microcalcification other features include asymmetric density and mass. High grade DCIS is associated with linear and branching calcification whereas low grade DCIS is associated with fine and granular calcification. Invasive cancer appear as a speculated mass. Ref: Oxford Desk Reference Oncology By Thankamma V. Ajithkumar, Page 152