Fig. 2

Low-dose, low-contrast CTPA and conventional-dose, conventional-contrast CTPA. A–C shows the axial image (A), coronal multi-plane reconstruction image (2B), and three-dimensional reconstruction image (C) of low-dose and low-contrast CTPA. The image has more noise, but it can meet the diagnostic requirements, and the subjective overall image quality score is 3 points. The red arrowhead indicated the location of the thrombus. The short red arrow indicated a pulmonary artery and the long red arrow showed a pulmonary vein, Arterial and branch scores were 4 points. D–F showed the Axial images (D), multiplane reconstructed coronal images (E), and three-dimensional reconstructed image (F) undergoing conventional CTPA. The image noise is low, and the subjective overall image quality score is four points. Yellow arrowhead indicated the location of the thrombus. The short yellow arrow indicated a pulmonary artery and the long yellow arrow showed a pulmonary vein, Vascular contrast was low, indistinguishable from pulmonary veins, and arterial and branch scores were three points