[Modern angiographic diagnostic techniques in the catheter laboratory]

Even at the beginning of the twenty-first century angiography still is the gold standard for imaging coronary arteries. Many limitations of this technique have facilitated advancements, such as quantitative coronary angiography and 3-dimensional reconstruction. The use of intravascular ultrasound has enabled a transmural in vivo imaging of the coronary arteries while creating cross-sectional images of the vessel wall. This led to a better evaluation of vascular plaques and the surrounding structures of the vessel. Optical coherence tomography is a new modality based on infrared light, which provides intraluminal and extraluminal imaging of vessels with a resolution of 10-20 µm, which is better than intravascular ultrasound (IVUS). However even this modern diagnostic tool is limited in the assessment of the relevance of an epicardial stenosis. Evaluation of the fractional flow reserve is a pathophysiological test, which measures the pressure before and after an epicardial stenosis and is able to assess the functional condition of a vessel with a high sensitivity and specificity. The so-called C-arm computed tomography (CACT; DynaCT Cardiac; Siemens, Erlangen, Germany) is a new application of an intraprocedural technique based on rotation of an x-ray source around a patient. It is able to generate information similar to that created by conventional computed tomography (CT) scans and offers the possibility to significantly enhance angiographic diagnostic modalities.