A 57y.o. presents with a cold pulseless R leg, a CT is done to ro aortic dissection. There is no dissection but the finding below is seen. What does it mean?

There is no PE.

dye is refluxing into the liver and there is a "half-moon" sign in the vena cava.

Our patient had dependent layering of contrast in the inferior vena cava which is a sign of cardiogenic shock.  This also occurs if a patient arrests during a CT and involves not only the IVC but the major tributaries of the hepatic veins.

Indeed,  our patient had cardiogenic shock along with an acute occlusion of the R common femoral vein.  She had a heart rate of 40 with complete heart block n the ED and a transvenous pacemaker was floated.  The patient was taken to the OR for her ischemic leg  and then to the cath lab where she was noted to have a right coronary occlusion and RV failure.  A right ventricular assist device was placed. Interestingly, the pacemaker placed correctly in the ED became completely entangled in the RV assist device.

In spite of milrinone, vasopressin , norepinephrine and a right ventricular assist device, the patient could not maintain her BP and expired.

An addendum was made to the original CT done in the ED stating the R coronary was occluded.  Her initial trop had been normal and peaked at 30.

Roth,  C, Sneider M, Bogot N, Todd M , Cronin.  Dependent Venous Contrast Pooling and Layering: A sign of Imminent Cardiogenic Shock.  American Journal of Radiology. 2006. 186:1116-19.

Tsai PP, chen JG, Huang JL, Shen WC.  Dependent pooling : a contrast-enhanced sign of cardiac arrest during CT. AJR. 2002;178:1095-99.

Jana M, Gamnagatti SR, Kumar A. Case series: CT scan in cardiac arrest and imminent cardiogenic shock. Indian J Radiol Imaging. 2010;20:150-53.