[The significance of the half axial projection in coronary angiography (author's transl)].

The proximal segments of the left coronary artery are foreshortended in the usual projections. By additional cranio-caudal (half axial) projections the X-ray beam can be directed perpendicular to these segments. In some patients lesions especially of the left main coronary artery or the proximal LAD can be seen or accurately evaluated only in the half axial projection, as demonstrated by examples. The clinical implications are discussed.