Hi, Hilum are basically present on the right and left side of the midline. They are the indicators where our bronchi (smaller airwyas) arise from the trachea (main central airway). There are various causes for prominant hilum-
In your wife's case most probably according to her symptoms she might be having prominant hilum on both sides of chest. Mostly the prominant hilum are seen due to enlareged lymph nodes. The cause of this is usually some infection. That is what your doctor wants to comfirm by repeating the X-ray at a different angle. The cause will be confirmed after the second X-ray, depending whether any blood tests are needed or not. There is normally nothing to worry about, as the cause is usually easily treatable. I would advise you to get the second X-ray done and then consult your doctor. In the mean time there is no need to panic.
Please remember to accept the reply if you find it useful. A BONUS and a positive rating would be duly appreciated,regardsDr. Gupta