An image processing apparatus and method take as input a pre-op reference image (OP) and a stream (A) of angiographic images (A1-A3). Based on multiple pre-defined regions of interest (ROIa-c) in the pre-op reference image (PO), the angiographic image best showing when displayed a respective one of the regions of interest (ROIa-c) is detected from among the stream (A) of angiographic images (A1-A3). The detected angiographic image is associated with the region of interest to form an associative data structure (DS). A graphical user interface (GUI) is generated that allows based on the associative data structure (DS) to retrieve the associated angiography upon a user selecting any one of the regions of interest (ROIa-c) on the graphical user interface (GUI).