A successful neuroendovascular procedure depends on accurate anatomical understanding of a target vessel in relation to surrounding anatomical structures or endovascular devices, such as coils and stents. During an endovascular procedure, with conventional or three dimensional (3D) rotational angiography, this type of information is extremely difficult to obtain in a timely manner. To overcome this drawback, a DynaCT was combined with low dose contrast injection to create CT angiography (CTA)-like images (DynaCTA). The images obtained were similar to those of conventional CTA but with better quality in analyzing vessels to surrounding anatomical structures and endovascular devices while the patient was on the table. The authors present three illustrative cases in which information added by the DynaCTA helped improve understanding of anatomy, and affected our clinical decision-making. Although better quality images may be obtained by other imaging modalities or careful angiographic interpretations, DynaCTA can be an easy and effective rescue technique worth keeping in mind in clarifying the relation of a vessel to surrounding anatomy.