Why in the age of CT scans and MRIs is a brain tumour mistaken for a psychiatric illness

The first author of this paper operated on two patients with brain tumour, who had been undergoing long-term treatment for depression. In the age of CT scans and MRIs, why are there still cases in which a brain neoplasia is mistaken for a psychiatric condition with consequent serious delays in diagnosis? In this article, we have highlighted what in our experience are three noticeable obstacles in achieving the right diagnosis.