CO2 angiography and enlarged CO2 angiography in cardiology

CO2 angiography is a simple, easy and absolutely safe method. Gaseous contrast is obtained by means of pure CO2, which is soluble in the blood. The gas is injected by hand into a peripheral vein, which is not exposed. Catheterization is not required, special preparation is unnecessary and standard radiological equipment is used. The method is free from the disadvantages of exploration with iodinated contrast medium and is a valuable addition to the latter since it can fill in lacunae, alleviate contraindications or deficiencies. As regards its clinical applications, the method has remained restricted to examination of the right atrial wall, where its main interest resides in the possibility of distinction between dilatation of the myocardium, pericardiac thickening or effusion in cases of cardiomegaly. By increasing the dose of CO2 and using adequate projections the authors developed a new method in 1968. This was called 'enlarged CO2 angiography' and permitted for the first time a constant visualization of the subhepatic veins and verification of portocaval and splenorenal anastomoses. The method also permits demonstration of the vena cava superior and inferior and renal veins. The results obtained with enlarged CO2 angiography have led to valuable clinical applications, for the main part already known, which have shown the advantages of the method. The new method was subsequently used for demonstration of the complete right cardiac cavities. In this manner certain disorders could be demonstrated. The use of CO2 permits further exploration in cardiology. On the basis of more than 1600 examinations a report is given on the technique, indications and results obtained with CO2 angiography and enlarged CO2 angiography in cardiology.