Zhang YF, et al. - Researchers here sought radiographic indications and relevant clinical symptoms of retrograde systemic-to-pulmonary artery shunt (RSPAS). Chest computed tomography angiography (CTA) was performed on 46 consecutive patients, with transpleural systemic arterial supply to the lung confirmed by surgery or conventional angiography. Comparison was performed between patients with the finding of RSPAS in CT scans vs those among whom no retrograde systemic-to-pulmonary artery shunt (NRSPAS) was present. CTA detected RSPAS in 20 patients (8 left and 12 right) and NRSPAS in 26 patients (14 left and 12 right). In RSPAS vs NRSPAS, more frequent occurrence of hemoptysis and sputum was reported. In NRSPAS, they more frequently identified single systemic supplying artery while in RSPAS, they more frequently identified multiple systemic arteries. The mean diameter of systemic arteries was significantly larger in RSPAS vs NRSPAS. The anatomic location of systemic arteries crossing the thickened pleura distributed more intensively in apical and costal pleura in RSPAS vs NRSPAS. Findings thus suggest differences in radiographic features of RSPAS vs NRSPAS. RSPAS may include enlarged and multiple systemic supplying arteries. And that may indicate higher risk of hemoptysis.