Most reliable sign of injury to intrathoracic aorta is -

Ans. is 'c' i.e., Obliteration of aortic knob contour * Several findings on the chest X ray are associated with the blunt injury to the intrathoracic great vessels.* The most reliable of these signs for the blunt aortic injury is loss of the aortic knob contour.Finding on Chest X-Ray Associated with Blunt Aortic InjuryPresence of widened mediastinum (> 8 cm at the aortic knob in adults)Deviation of the trachea, nasogastric tube, or endotracheal tube to the rightPresence of an apical cap of pleural fluidDepression of the left mainstem brochus > 140deg from trachea Obliteration of aortic knob contour"Funny" looking mediastinum