Pulmonary embolism is best diagnosed by

D i.e. CT Scan Investigation of choice (IOC) is CT angiography (contrast CT) followed by pulmonary aeriography followed by a ventilation - perfusion scanQ. Advantages & Disadvantages of various tests for DTE Dx Test Advantages Disadvantages 1. Plasm D-dimer ELISA Normal results make PE highly unlikely Level is elevated in various systemic illnesses 2. Lung (V-P) Scanning Standard initial imaging test for Most scans are neither high probability nor PEQ. High probability scans are reliable for detecting PE normal/near normal scans are reliable for precluding PE normal/near normal; most are equivocal 3. Pulmonary angiography Gold standard for diagnosisQ Invasive, Costly & Uncomfoable ; so not a first line investigation 4. CT angiography (helical) - Noninvasive, widely available test - Initially it was a sensitive method of that has replaced pulmonary detecting central segmental, lobar & main angiography (conventional) as the pulmonary aery emboli upto 4th order vessel main stay investigation for PEQ. (-- 7mm diameter) i.e., from aoic arch to - Stratifies risk, obtains images of inferior pulmonary vein. However, with RV & LV advent of helical & multidetector CT (MDCT) has improved resolution of peripheral aeries upto 6th order.