You're not the only person wondering such things.
What would it take to have it re-done?...*sigh* in this case, probably a act of God himself!
During the 2000 trial, neurologist James Barnhill testified on behalf of Mr. Schiavo about Mrs. Schiavo's condition. Based on his review of her CAT scans, he told the court that most of her brain was destroyed, replaced by scar tissue and spinal fluid, leaving her no hope of recovery. But Florida neurologist William Hammesfahr, in a June 2001 affidavit, stated that his own review of Mrs. Schiavo's CAT scans revealed significant, viable brain tissue. "The CAT scan readings or MRI readings of Ms. Schiavo's brain were misrepresented to the court during the trial in January 2000," Dr. Hammesfahr said.
Brain scans are taken slice-by-slice. A black layer on one "slice" does not indicate what will be found in the next "slice"