Severe shortness of breat...

A 60-year-old man with severe shortness of breath and an ineffective cough arrives at the emergency department. He was treated three weeks ago at a nearby hospital for congestive heart failure. Upon examination, he exhibits normal vital signs and obvious bilateral pitting oedema in the lower limbs. The chest radiograph shows the opacity in this picture. The technician advises giving diuretics and taking another chest radiograph the next day.