If intracranial pathology is still suspected after a normal head CT, an MRI is necessary.
Brain MRI can usually provide more information than brain CT, is a clearer imaging test, has a high degree of soft tissue resolution, some abnormalities can not be seen on CT, but can be shown clearly on MRI, and thus often more effective and earlier detection of lesions than CT.
Moreover, in many cases, CT is unable to visualize the lesion in the short term, so further MRI is required.
One of the disadvantages of MRI is its high cost, so doctors do not always prescribe MRI at the first visit for all patients.
Therefore, MRI is necessary if the CT of the head is normal and the presence of intracranial lesions is still suspected in view of the clinical symptoms, signs and progression of the disease.