Is a liver biopsy accurate? the livers pretty big, so isnt it likely it could miss something? how can the doctor be sure hes getting a sample of the damaged part?

If : If the goal is to get a general sample of liver tissue to evaluate for cirrhosis, venous obstructive disease, abnormal deposits of iron, or similar organ-wide problems, then a biopsy is pretty easy and "missing something" is unlikely. The bigger the liver, the easier it is. On the other hand, if there is one specific spot in the liver that's abnormal, and your doctor is aiming for just that spot, then missing the target is more likely. In such situations, we usually have a pathologist present during the biopsy to look at the tissue as we collect it. The pathologist will not be able to make a final diagnosis in real time, be he or she should be able to say whether or not the tissue that's been collected will be adequate for making that final diagnosis.

Liver biopsy: Many diseases that affect the liver, involve the liver uniformly so that a biopsy of a "random" area should show pertinent changes. If there is a specific mass lesion that is being targeted, it is important to have the biopsy performed with some type of imaging guidance to insure obtaining pertinent tissue.