How can I convince my mother to get tested for Alzheimer's?

My mother is at risk for developing Alzheimer's disease. Her mother, grandmother and aunts all died of the disease. My mom, although still quite active and healthy, has started to show signs of memory loss. I know the earlier a diagnosis is made the better in taking steps that could possibly prolong her quality of life. However, my mother does NOT want to know if she has the disease and refuses to get tested. She gets extremely angry and upset when I bring it up--even though I desperately want her to take any steps she can to prolong a healthy mental state. Do you have any advice for convincing her to get tested? She is quite capable, active and aware of her environment and surroundings--so I cannot "trick" her into getting tested nor even attempt to reach her doctor behind her back. She is also quite aware of how the disease progresses as she nursed my grandmother for the last 10 years of her life as she suffered with Alzheimers. Any advice would be greatly appreciated.