Different examples of swirl sign and swirl sign mimics. Axial images of 6 different patients with ICH. (a–c) Show different forms of swirl sign; well defined in a, irregular in b, and streak-like in c. (d) Shows homogeneously hyperattenuated left-sided putaminal haemorrhage with no swirl sign. (e) Shows right-sided subacute frontal haemorrhage with lower attenuation (black arrow) at the outer posterior portion indicating beginning resorption (clot retraction) that should not be addressed as swirl sign. (f) Shows left-sided subacute frontal haemorrhage with multiple blood-fluid levels (short arrows) that should not be addressed as swirl sign.
Selariu et al. BMC Neurology 2012 12:109 doi:10.1186/1471-2377-12-109