Endovascular Surgical Neuroradiology (ESN), also known as Neurointerventional Surgery (NIS), Interventional Neuroradiology (INR), and Endovascular Neurosurgery, is a medical subspecialty of Radiology, Neurosurgery, and Neurology specializing in minimally invasive image-based technologies and procedures used in diagnosis and treatment of diseases of the head, neck, and spine. History Diagnostic angiography Cerebral angiography was developed by Portuguese neurologist Egas Moniz at the University of Lisbon, in order to identify central nervous system diseases such as tumors or arteriovenous malformations. [Source: Wikipedia ]