3D quantitative coronary angiography

Conventional coronary angiography is a two dimensional visualization of coronary anatomy. There are inherent limitations to this like foreshortening which results from angiographic views which are not perpendicular to coronary segments being visualized. This is taken care of by taking multiple orthogonal views so that significance of a lesion is not missed by foreshortening in one view. Various three dimensional (3D) reconstruction softwares have been developed to overcome this problem. But these have not become part of routine coronary angiographic practice unlike in neuroimaging where 3D reconstruction of cerebral angiography is routine practice and has been built into modern angiographic equipment. This is mainly due to limitation in case of coronary imaging due to the constant motion as a result cardiac action where as cerebral vessels are relatively immobile and allows easy 3D reconstruction during a single shot of rotational angiography with automatic delivery of contrast and gantry rotation. One of the software systems for 3D coronary imaging (CardiOp-B) has real time and off line analysis with 3D reconstruction using all the information from two 2D angiograms into one 3D image [Gradaus R et al. Clinical assessment of a new real time 3D quantitative coronary angiography system: evaluation in stented vessel segments. Catheter Cardiovasc Interv. 2006;68:44-9]. This system derived measurements correlated well with predefined measures of stents at designated inflation pressures. Another study compared 3D imaging system with intravascular ultrasound (IVUS) measurements [Tu S et al. A novel three-dimensional quantitative coronary angiography system: In-vivo comparison with intravascular ultrasound for assessing arterial segment length. Catheter Cardiovasc Interv. 2010;76:291-8]. They could demonstrate good correlation between IVUS derived measurements and 3D quantitative coronary angiography.