text_1: 回顾性 分析 提示 , 临床 验前 概率 ( C - PTP ) 低 的 患者 如果 d - 二聚体 水平 低于 1 , 000 ng / mL , C - PTP 中等 的 患者 如果 d - 二聚体 水平 低于 500 ng / mL , 则 可 排除 肺栓塞 .
  
text_2: retrospective analyses suggest that pulmonary embolism is ruled out by a d @-@ dimer level of less than 1000 ng per milliliter in patients with a low clinical pretest probability ( C @-@ PTP ) and by a d @-@ dimer level of less than 500 ng per milliliter in patients with a moderate C @-@ PTP .
  