MGD can be calculated from measurements made with poly(methyl methacrylate) (PMMA) blocks.
It is often used to compare typical doses to patients between different centres or internationally, and is the preferred measure of the potential risk from mammography.
converts from incident air kerma to MGD, with a glandularity of 50%, based on breast thickness and HVL.
[4][5] MGD is typically used to define limits on mammography exposures by national and international organisations such as the European Union and International Atomic Energy Agency, at <2.5 milligray (mGy) per exposure to a standard breast (4.5 cm PMMA).
[6] In routine quality assurance testing of mammographic equipment, MGD measurements for a range of effective breast thicknesses with PMMA, and from real patient exposures, is widely recommended.