had a 40ish year old guy the other day with left lower extremity pain and swelling, as well as tachycardia to the 120s. he didn't have any risk factors for PE, and had no chest pain or dyspnea, so i decided i would get a d dimer, and based on that, rule him out. my attending adds on a venous duplex, which is obviously appropriate. however, it's read as no signs of DVT. meanwhile, his dimer comes back >1000. attending tells me to d/c the patient without the scan, because a negative venous study "rules out PE." i didn't fight back, but i feel like i should have. in the face of tachycardia and an elevated dimer in a patient with a painful, swollen leg, do you really send them out without spinning their chest? regardless of what the venous study shows?