Septic thrombosis of the transverse and sigmoid sinuses: imaging findings.

The purpose of this study was to evaluate the contribution of magnetic resonance imaging (MRI) to the diagnosis of septic thrombosis of transverse and sigmoid sinuses to analyze the different steps of the diagnosis and to identify the origin of the difficulties in diagnosis. This retrospective study included eight patients aged 53-81 years (mean age: 61.9 years) with proven or highly probable septic thrombosis of transverse and sigmoid sinuses. All patients underwent a pre- and post-contrast enhancement brain CT scans and MRI. MR venogram (n=4) and HRCT of the temporal bone were performed when diagnosis was under discussion. After admission, the delay in diagnosis of lateral sinus thrombosis ranged from 8 to 60 days, with an average of 27 days (SD: +/-12.8). The delay in diagnosis was mainly due to non focused CT scans (6/8) or MR images performed at the initial presentation and absence of systematic radiological reading of the related fatty spaces and of skull base in bone windows (3/8). Diagnosis of septic origin of the thrombosis is of great importance, as it completely modifies the therapeutic planning of the patients. However, it remains a difficult challenge due to its lack of suggestive neurological or otolaryngologic symptoms.