Evaluation of AAC

A standard (posterior-anterior) chest radiograph (40 × 40 cm; Curix HT 1.000G Plus, Agfa, Mortsel, Belgium) was acquired with the patients standing up (Thoramat, Siemens, Erlangen, Germany). The focus-patient distance was set at 150 cm. An automated exposure control having a fixed tube voltage of 117 kV was used. AAC was graded as follows: grade 0, no visible calcification; grade I, small spots of calcification or thin calcification on the aortic knob; grade II, one or more areas of thickened calcification; and grade III, circular calcification on the aortic knob [11] (Fig. ​(Fig.1).1). Two examiners, who were blinded to the findings of RRI, reviewed AAC on the chest radiograph. One hundred chest radiographs, randomly selected for the evaluation of AAC, were assessed independently by two cardiologists to assess the reliability of AAC diagnosis. The kappa value was detected to be 0.781 and p to be < 0.001.

Grading of aortic arch calcification.