Fall leads to CT scan then MRI now I am worried.

[Pack2u]

My wife fell and hit her head.  We went  to the ER 2 days later just to make sure she was ok. The PA examined her and recommended a CT scan (she vomited once after the fall that was his reason for the CT scan) The CT scan came back with some questions (some white areas that the PA was unsure about) He recommended we see a neurologist look at the CT scan (neurologist not on site during visit to ER) We went the the Neurologist the next  day and he review the scan from a CD disk we had been given at ER. The neurologist seemed like the questioned areas that the PA saw (some white areas, possible swelling) were not a major concern but told us she should get an MRI. He wanted a clearer picture then the what the CT scan had shown.  She had no symptoms or issues before the fall. He gave us no indications on what he thought it was on the CT scan. We are both nervous and looking for any advice on what may be wrong. Thanks in advance for any information. She has the MRI in a few days ( 1 1/2 weeks from the fall). If he were that concerned wouldn't he have  had her do an MRI right away?? Since the fall she has been getting better everyday and seems to be her regular self.