Sethwala A, et al. - The clinical parameters for advising a Computer Tomography Pulmonary Angiogram (CTPA) were comprehensively inspected in this study. Furthermore, this study strived to establish which among these were related to the presence of pulmonary embolism (PE). The findings supported the negative predictive value of the D-dimer at excluding PE. The strongest pre-test predictors of PE in the study cohort were a prior history of venous thromboembolism (VTE), risk factors for VTE and elevated troponin. It was noted that neither parameters generating requests for CTPA, such as vital signs or the presence of chest pain, correlated with the presence of PE.