The Hot Quadrate Sign on a Ventilation-Perfusion (V/Q) Scan.

The hot quadrate sign is defined as an intense arterial enhancement in the hepatic quadrate lobe, most frequently encountered on CT angiograms in patients with central venous occlusion. It has also been described as focal uptake on technetium-99m (Tc99m) sulfur colloid scans. We present an unusual case of focal uptake in the hepatic quadrate lobe on a ventilation-perfusion (V/Q) scan, corresponding to the hot quadrate sign in a 42-year-old patient with chronic kidney disease and central venous occlusion.