hello. I have 8 year son. he has got cough. doctor examined him by stethoscope and told me chest is clear ,cough is in his throat.but when I gave him my son's chest x ray ,he told me that yes, infection is there. my question is how stethoscope couldn't detect chest infection? why x ray detected it? is it possible that chest infection is detected by x ray and stethoscope fail to detect chest infection????