I saw the painting at my doctor's office and asked him where he got it. He said friends of his were in Bologna, Italy, on vacation and bought it for him. I asked him the name of the painter and he said he didn't know. We looked closely at the signature but it was just too wavy to read.

The painting wasn't holographic or anything but it was kinda 3D. The picture came outwards, literally. Maybe the guy used paper machet? It looked like a hallway/corridor outside and it started large at the front and got smaller and smaller "into" the painting.

I want to find out for myself who this painting is by so I can get it for myself, but my doctor said if I find out who did it, to let him know, and we are good friends, so I just want to know in that respect too. If you have any idea, please let me know.

I looked up Bologna, Italy, on wikipedia and looked at many people from the city, but nearly all of the painters had pictures of Jesus, Mary, and the Crucifixion.

I am afraid it is most unlikely that you are going to find the name of the person who painted this picture. If someone bought it for your doctor - unless he is very wealthy - it is most probably that it was painted by a contemporary artist from Bologna, or its surroundings, whose work is not well known but attractive and marketable.
As you know in holiday cities, outdoor display of pictures, are a regular sight. And it may well be that the man who bought it for the doctor, struck by its original format and unusual appearance, purchased it there.
If it had been painted by a well -known artist, then wouldn't the person who gave it to your doctor - have told him so proudly?