Congenital Absent Pulmonary Valve Syndrome (APVS) is a rare heart defect often associated with other cardiac anomalies, with approximately 5.5% of cases related to trisomy 13. This case report describes a fetus with trisomy 13, presenting with the rare combination of absent pulmonary and aortic valves, along with an interrupted aortic arch. The patient was a 34-year-old pregnant woman with an otherwise normal pregnancy. At 12 weeks, ultrasound examination revealed thickened nuchal translucency (NT), ethmocephaly with proboscis, and a heart showing a single large vessel with alternating red and blue blood flow. Fetal autopsy confirmed the interrupted aortic arch and the absence of both valves. Chromosomal analysis revealed trisomy 13, supporting the genetic diagnosis. The combination of APVS with absent aortic valve and trisomy 13 is extremely rare, highlighting the importance of early prenatal diagnosis and genetic screening. Although the pregnancy ended in termination, early diagnosis allowed the family to understand the prognosis and make informed decisions, underscoring the critical role of ultrasound screening and genetic testing in prenatal diagnosis.

Conotruncal anomalies, also referred to as outflow tract anomalies, are congenital heart defects that result from abnormal septation of the great vessels' outflow tracts. The major conotruncal anomalies include tetralogy of Fallot, double-outlet right ventricle, transposition of the great arteries, truncus arteriosus, and interrupted aortic arch. Other defects, which are often components of the major anomalies, include pulmonary atresia with ventricular septal defect, pulmonary valve agenesis, aortopulmonary window, and double-outlet left ventricle. CT has emerged as a robust diagnostic tool in preoperative and postoperative assessment of various congenital heart diseases, including conotruncal anomalies. The data provided with multidetector CT imaging are useful for treatment planning and follow-up monitoring after surgery or intervention. Unlike echocardiography and MRI, CT is not limited by a small acoustic window, metallic devices, and need for sedation or anesthesia. Major advances in CT equipment, including dual-source scanners, wide-detector scanners, high-efficiency detectors, higher x-ray tube power, automatic tube current modulation, and advanced three-dimensional postprocessing, provide a low-risk, high-quality alternative to diagnostic cardiac catheterization and MRI. This review explores the various conotruncal anomalies and elucidates the role of CT imaging in their pre- and postoperative assessment. Keywords: CT, CT Angiography, Stents, Pediatrics © RSNA, 2022.