Diagnostic of acute pulmonary embolism is

Ans. d (D-dimer assay). (Ref. Harrison, Medicine, 18th/Chapter 103; fig. 58-2)EVALUATION OF ACUTE PULMONARY EMBOLISM# ECG may show RV hypertrophy with strain, RBBB, increased HR and T-wave inversion in V1 to V4.# CXR is frequently normal. However Palla sign (enlarged right descending pulmonary artery) or Westermark's sign (decreased pulmonary vascular markings peripherally) or Hampton's hump.# If clinical likelihood is low, then d-dimer, ELISA and USG lower extremities are done# D-dimer is elevated in number of conditions other than pulmonary embolism, however, a negative D-dimer assay suggests that likelihood of PE is low. Patients with a low likelihood of DVT or a low-to-moderate likelihood of PE can undergo initial diagnostic evaluation with d-dimer testing alone without obligatory imaging tests. If the d-dimer is abnormally elevated, imaging tests are the next step# VP lung scans are done in any stable patient with suspicion of PE and are investigation of choice.# CT with contrast may be helpful, and may supplement VP Scan in coming days.# Pulmonary arteriography is 'gold-standard' and definitive