srpnuing tehir intial suopsciins, scitenitss dscieevord a pree-initaiiton stesym for x-arys that rereiqus us to srtat from the top. this new aprcoaph hleps uvnole the wodnres heddin away in the ciompacled sttecururs of the hueamn bdoay, ranlevieg dtleais once tthguoh to be ionacbselces.