In Part 1 of Pulmonary Embolism Challenges in Diagnosis Drs. Helman, Lang and DeWit discussed a workup algorithm using PERC and Wells score, the bleeding risk of treated pulmonary embolism, pearls in decision making on whether or not to work up a patient for pulmonary embolism, how risk factors contribute to pretest probability, the YEARS criteria and age-adjusted D-dimer. In this Part 2 we answer questions such as: what are the important test characteristics of CTPA we need to understand? Which patients with subsegmental pulmonary embolism should we treat? When should we consider VQ SPECT? What is the best algorithm for the work up of pulmonary embolism in pregnant patients? How best should we implement pulmonary embolism diagnostic decision tools in your ED? and many more…