For women who have had breast implants, how do doctors go about doing a breast scan??

My mum went for one recently, they asked if she has breast implants they needed to know for some reason and i just wondered why they ask that and if the scan is done differently because of that how they go about it. Thanks.
Answer:
Yes, breast implants impair the ability of the scan to pick up abnormalities so X-ray is the second choice. Here's breastcancer.org's take on it:
http://www.breastcancer.org/breast_impla...

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