True about ARDS is all except

A less severe form is called acute lung injury (ALI).A PaO2/FiO2ra of less than 300 mm Hg with bilateral infiltrates indicates acute lung injury (ALI). ARDS is characterized by:Acute onsetBilateral infiltrates on chest radiograph sparing costophrenic anglesPulmonary aery wedge pressure< 18 mmHg (obtained by pulmonary aery catheterization if PaO2:FiO2< 200 mmHg (26.7 kPa) To summarize and simplify, ARDS is an acute (rapid onset) syndrome that affects thelungs widely and results in a severe oxygenation defect, but is not due to hea failure.