Overview
Considerable progress has also been made in reducing the radiation dose. This means that the coronaries can be visualized with a dose of less than 1 mSv using state-of-the-art equipment.
Dynamic CT angiographies of the heart, which are required to assess the success of interventional closure of the left atrial appendage, or CT examinations following interventional repair of the mitral valve are now also possible with a very low radiation dose.
Last year, clinical research focused on so-called “kidney-friendly” CT angiography, in which only small amounts of iodine-containing contrast agents are used. The specific attenuation behavior of iodine as a function of the energy of the X-rays is used here.
Today, for example, CT pulmonary angiography for the diagnosis of pulmonary embolism uses only approx. 20 ml of contrast medium, and ECG-triggered CT angiography of the aorta for planning a TAVI (transcatheter aortic valve implantation) or an endovascular intervention is now performed with only 30 ml of contrast medium.
Due to the frequency of renal insufficiency in patients qualifying for TAVI and endoaortic procedures, this reduction in the amount of contrast medium is a major advantage.
Precise pre-interventional visualization of the anatomy is essential for planning TAVI interventions. CT can be used to measure the aortic annulus and the distance between the coronary ostia and the annulus plane with a high degree of accuracy, which is crucial for selecting the correct prosthesis size. In addition, CT allows precise visualization and quantification of the diameter of the pelvic vessels for planning the approach (femoral vs. transapical).
