1-Day-old male with complex congenital heart disease including left atrial isomerism and interrupted IVC underwent CCTA for anatomic definition of the cardiothoracic artery anatomy. Contrast was injected by hand through an UVC (white arrow). The tip of the catheter which was positioned in the sinus venosus just below the level of the atrium is obscured by the dense contrast material which has refluxed into the hepatic veins (HVs). The opacified morphologic left atrium (mLA) to the right of midline has an appendage with left sided morphology (black arrow) with a narrow orifice. Though much of the contrast volume is left in the atrium and hepatic veins the left ventricle (LV) and aortic arch (AA) are adequately opacified