The effect of rotation from a primary PA projection on PSD for female patients: (A) LAO/RAO rotation and (B) CRA/CAU rotation. The effect of rotation from a primary PA projection on PSD for female patients: (A) LAO/RAO rotation and (B) CRA/CAU rotation. Vertical bold lines indicating the AAO. The results for each format group represent the X-ray field format and size from the group that required the largest AAO (AAO, angle to avoid overlap; PSD, peak skin dose; CAU, caudal; CRA, cranial; LAO, left anterior oblique; PA, posteroanterior; RAO, right anterior oblique). Alexander S Pasciak et al. Open Heart 2014;1:e000141 ©2014 by British Cardiovascular Society