Question category: Respiratory
A 28 year old female presents with acute onset of shortness of breath and pleuritic chest pain. She has just recently flew back from Australia . She has no past medical history although she is on the contraceptive pill. On examination there is evidence of a swollen tender left calf. On auscultation of the chest it is clear however she is tachycardic. A CXR reveal nil focal. What is the most likely diagnosis?