text_1: 我们 开展 了 一项 前瞻性 研究 , 本 研究 认为 C - PTP 低且 d - 二聚体 水平 低于 1 , 000 ng / mL 或者 C - PTP 中等 且 d - 二聚体 水平 低于 500 ng / mL 的 门诊患者 可 排除 肺栓塞 , 而 不 需要 进一步 检查 .
  
text_2: we performed a prospective study in which pulmonary embolism was considered to be ruled out without further testing in outpatients with a low C @-@ PTP and a d @-@ dimer level of less than 1000 ng per milliliter or with a moderate C @-@ PTP and a d @-@ dimer level of less than 500 ng per milliliter .
  