**7. Intravascular ultrasonography (IVUS)**

IVUS is an intracoronary imaging technique which provides qualitative and quantifiable features of the coronary anatomy in ANOCOR. Its high spatial resolution about 0.15 mm achieves a good anatomic visualization of the coronary artery wall. Other imaging modalities are not too competitive to analyse the shape and area of the ectopic orifice, and to identify an intramural segment. In this field, the contribution of the group of Angelini has been essential with a routinely use of IVUS in ANOCOR with a suspected intramural course (Angelini et al., 2003, Angelini et al., 2006, Angelini, 2007, Angelini & Flamm, 2007). In ANOCOR with intramural segment, IVUS imaging often visualizes the aortic wall at the level of the ectopic orifice. Several features, similar to histological and anatomical characteristics of ANOCOR with an intramural course, are well depicted by IVUS. Pharmacologic provocative tests may be associated during IVUS procedure. IVUS use is mentioned in ACC/AHA 2008 guidelines for adults with congenital heart disease, with a recommendation of class IIa and a level of evidence C, in order to delineate potential mechanisms of flow restriction (Warnes et al., 2008). Angelini et al. have defined several consistent IVUS characteristics regarding to ANOCOR with intramural segment (Angelini & Flamm, 2007).
