Clinical and radiological pitfalls in Isolated cortical venous thrombosis. Don’t miss the “last slice”

A brain CT scan without contrast revealed on the last slice, a hyperdense serpiginous vessel in the left frontal lobe, ie a “cord sign”, thus suggesting a diagnosis of a thrombosed frontal cortical vein (Figure 1a, arrow). On brain MR imaging on a 3T scan the conventional sequences were normal: T1-weighted-image (T1WI), T2-weightedimage (T2WI), fluidattenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI). Susceptibility-weighted imaging (susceptibility-weighted angiography, SWAN sequence) (Figure 1b), showed a dark serpiginous vessel in the area relative to that of the “cord sign” on the non-contrast CT, confirming the diagnosis of thrombosed frontal vein. 3-Dimmensional contrast-enhanced T1WI MRI sequence (CE 3D T1) showed on multiformat reformat (MPR) an intraluminalfilling defect surrounded by contrast in a left frontal vein at the same level (Figure 1c, arrow), suggestive of an intraluminal thrombus.