CT quadrate lobe hot spot sign

ABSTRACT

A 14-year-old girl visited our hospital with pyrexia of unknown origin. In view of suspicion of tuberculosis, various haematological and radiological investigations were done. Further examinations revealed titres positive for lupus anticoagulant syndrome. Contrast-enhanced computed tomography [CT] of the chest and abdomen was also advised for further evaluation, which revealed type II superior vena cava obstruction. Contrast-enhanced CT of the abdomen revealed an interesting observation in the left lobe of the liver, which is known as the hot spot sign. CT quadrate lobe hot spot sign' was first described by Ishikawa in 1983. It manifests as an area of intense focal wedge-shaped enhancement of the quadrate lobe [functionally a part of the left lobe of the liver and designated segment IVb in the Bismuth-Couinaud classification system] of the liver in the arterial and venous phase [figure 1].1 This hot spot sign was initially observed on 99mTc sulphur colloid scan of the liver as a focal area of increased radiopharmaceutical uptake and was diagnostic of superior vena cava syndrome.2 Hot spot sign is caused by portosystemic venous shunting between the superior vena cava and the left portal vein via the internal mammary and paraumbilical veins along the ligamentum teres, secondary to superior vena cava obstruction