Magnetic resonance imaging (MRI) versus computed tomographic scan (CT scan) of brain in evaluation of suspected cavernous sinus syndrome.

Background And Purpose: The cavernous sinus is a unique region owing to anatomical factors and the pathologies affecting it. The diagnosis of cavernous sinus syndrome (CSS) predominantly relies on clinicoradiological correlation. We studied the utility of computed tomographic (CT) scan versus magnetic resonance imaging (MRI) in the diagnosis of CSS.

Methods: A prospective observational study was conducted in a tertiary care center in north India. All patients presenting with a clinical syndrome of cavernous sinus involvement with radiologically confirmed lesions were enrolled in the study. MRI and CT scan with cavernous sinus cuts were done and reviewed by experienced neuroradiologists for cavernous sinus lesions and compared with the final diagnosis. Sensitivity and specificity were calculated.

Results: We included 48 patients in our study. A final diagnosis was achieved in 41 out of 48 (85.6%) patients. Fungal infections (16 (33.3%)) constituted the commonest cause of CSS, followed by neoplastic involvement (13 (27.1%)) and Tolosa-Hunt syndrome (12 (25%)). Vascular involvement was seen in three (6.3%) patients. Other rare causes were seen in four (8.3%) patients. CT scan had an overall sensitivity of 14.6% in achieving a final diagnosis, whereas MRI had an overall sensitivity of 70.7%, with a statistically significant difference ( < 0.001).

Conclusions: Although CT scan is a relatively cheap and accessible resource, its role in CSS diagnosis and management is limited because of poor yield. Hence, it is prudent to do an MRI as an initial investigation in cases of CSS.