Is there any legal way for me to dispute all those useless services and that huge bill that the hospital charges me for my CT scan?

After an auto crash, I suffered head concussion. I was shocked and incoherent so they took me to the emergency, where I asked a CT scan just for the head because nothing else was hurting. Instead, while I was under shock and confused they gave lots of things to sign saying that is consent forms without explaining anything. When I got the bill it was over $17,000. I learned that they did CT scans all over the body- head, thorax, cervical, abdomen, and pelvis, everything. I now, live with that huge fear after all that radiation. I know they wanted to get as much as possible from the insurance. The problem is that the police report (that was ready only after almost a month) stated that it was my fault for being rear ended, and according to my auto insurance, the emergency room was paid only $5000. Had no active health insurance at that time how on earth I will deal with that $12,000bill that was useless. All I asked for was a head CT scan and they irradiated me all over. After I rested a little and became aware I heard the doctor saying that he has an order for to X-ray my shoulder for no reason, because nothing was hurting and I was able to move freely, so I refused. Now, I barely able to pay bills month to month and that bill am impossible to fit in even with a payment agreement. More that I feel that was over extensive and useless investigation.