I didn't read all the responses on the thread so this may have already been covered. I used to work for a med-mal attorney. A good med-mal attorney will consult with you, for free, and tell you up front if the case is worth pursuing or not. If the case is worth pursuing, they will work on a contingency basis.Never sued anyone in my life. It would be for my wife, anyway. About a year ago she was having some pains in her ankle. She went to a specialist who took an x-ray, didnt see a fracture, but said "Lets just go ahead and treat it like one." Bought special insoles for her shoes, had to wear a boot for 8 weeks, etc. Nothing really worked...in fact the pain got a bit worse.
Fast forward to today and she finds out she has a huge ass lesion that has eaten away all the cartilage in her ankle and now they have to decide whether they can go in and insert new cartilage, or simply replace the entire fuggin ankle. The lesion could have been spotted easily by a simple MRI scan.
Needless to say were not pleased.
Just playing devil's advocate here, depending on your insurance, don't be too pissed at the doctors. If she didn't really bitch and gripe at the doctor that the pain wasn't improving then they wouldn't know to put her through an MRI

Additionally, HMOs will refuse payment for imaging studies without sufficent cause. If she had suffered some sort of trauma and wasn't in the doctors office complaining about unremitting pain ... see where I'm going? Malpractice lawsuits shouldn't be so much about missing a diagnosis that could have easily slipped under the radar, but more about really fucking up (i.e., ob/gyn dropping the baby at delivery, surgeon leaving a clamp inside someone, etc.).
Anyway, a good attorney will be honest with you. Best of luck.