thanks for writing us on HCM
parahilar and paracardiac shadows may be seen in many conditions but most commonly in heart failure
premature baby can frequently go to heart failure but along with x-ray features there will also be clinical features like pedal swelling, engorged neck vein, tachycardia
this shadow again may be due to recurrent chest infections
in a premature baby for that the baby is needed to treat with proper antibiotics and pediatric intensive care.