35 year old male with history of 4 weeks of immobilization for fracture femur developed sudden onset of chest pain and hemoptysis.  ECG shows s1 Q3 T3 pattern. Diagnosis?
Ref. Grainger and Allison's Diagnostic Radiology. Page. 50
 
Pulmonary embolism (PE) usually arises from a venous thrombosis in the pelvis or legs

Risk factors include any cause of immobility or hyper coagulability .
Clinical features include :pleuritic chest pain ,sudden onset of breathlessness (most common),hemoptysis ,dizziness ,syncope .
ECG findings include sinus tachycardia (most common ) , S1Q3T3 (Most characteristic)
Acute myocardial infarct
COPD
Pulmonary embolism
Cor pulmonale