Hi thanks for contacting HCM... As your child having chronic headache you have advised investigation with MRI... Usually other common causes ruled out first and then if needed MRI like higher investigation done .... Here search for /chronic sinus infection/tooth infection / ear infection / hypertension / dehydration or flu ruled out first ..... For that physical examination done and if needed specific investigation done .... Treated then accordingly ...... Sometime anemia could be cause for headache for which CBC done .... If needed for that iron and vitamin supplementation given .... You can post follow up reports for more guidance after getting examined. Take care