Hi Vince,
I can only speak for myself. I had the needle biopsy under CT Scan on my liver. And it really was a piece of cake. But, that was because they gave me a drug that was the equivalent of about 4 or 5 Margaritas..and if I said anything they gave me more. I just this week was speaking to another lady that had it done and she said the same thing.
Wish I could tell you what it was, but evidently it doesn't have a long lasting effect. The recovery area only looked to make sure I wasn't bleeding and was coherent, then they sent me home.
Hope it goes that well for your Mom.
Take care,
Dinah