 measur pericardi fluid correl -cholografin ihsa heart scan 23 patient undergo open-heart surgeri pericardi content accur measur 11 addit patient examin autopsi pericardiocentesi isotop photoscan heart correl accur diagnosi pericardi effus ratio maximum transvers cardiac diamet scan roentgenogram patient 100 cc pericardi fluid ratio greater 0 80 case effus 200 cc measur differ diamet visibl separ cardiac blood pool pulmonari vasculatur liver aid diagnosi pericardi effus 200-300 cc greater detect isotop photoscan cardiac dilat hypertrophi decreas sensit techniqu definit diagnosi pericardi effus cardiomegali exist 