Accuracy of unenhanced CT in the diagnosis of cerebral venous sinus thrombosis

Objectives To evaluate the diagnostic performance of unenhanced brain CT (NECT) in identifying patients with cerebral venous sinus thrombosis (CVT). Methods Forty-eight consecutive patients with CVT and 48 healthy controls were included in our retrospective study. All patients underwent NECT and CT/MR angiography within 24 h. Two radiologists independently evaluated NECT images for the presence of sinus hyperdensity; discrepancies were solved by consensus. Sinus attenuation was measured in seven sites. The obtained data were compared with the presence of CVT at CT/MR angiography and with patients' hematocrit. Results Interobserver agreement in sinus hyperdensity detection was good (k = 0.64). The presence of sinus hyperdensity at NECT enabled to detect patients with CVT with 81% sensitivity, 77% specificity, 78% PPV, and 80% NPV. Mean attenuation was significantly higher in sinus segments involved by CVT than in patent ones (62.4 +/- 10 versus 55.6 +/- 6 HU,p < 0.0001). ROC analysis showed that a cutoff value of 63 HU enables to detect patients with CVT with 52% sensitivity and 88% specificity. Hematocrit values were significantly correlated with patent sinus segments attenuation (r = 0.19). Conclusions The presence of sinus hyperdensity at NECT enables to detect patients with CVT with 81% sensitivity and 77% specificity. A sinus attenuation cutoff value of 63 HU can be used in order to increase specificity, but lowering sensitivity.