text_1: 目前 已经 确定 , 如果 患者 的 肺栓塞 C - PTP 低且 d - 二聚体 水平 低于 500 ng / mL , 则 认为 肺栓塞 可 排除 1 - 3 , 5 , 8 .
  
text_2: it is now well established that pulmonary embolism can be considered to be ruled out if patients have a low C @-@ PTP for pulmonary embolism and a d @-@ dimer level of less than 500 ng per milliliter.1 @-@ 3,5,8
  