Dong Hoon Lee, Presenter: Nothing to Disclose

Eunhee Kim MD, Abstract Co-Author: Nothing to Disclose

Hyung-Jin Kim MD, Abstract Co-Author: Nothing to Disclose

Han Bee Lee MD, Abstract Co-Author: Nothing to Disclose

Sung Tae Kim MD, Abstract Co-Author: Nothing to Disclose

Yoon Duck Kim, Abstract Co-Author: Nothing to Disclose

CT of the orbit in direct coronal plane is a useful technique for diagnosing orbital varix. Sometimes, the superior ophthalmic vein (SOV) is substantially dilated on direct coronal CT scans, which might lead to the misdiagnosis of varix. The purpose of this study is to investigate the degree of distensibility of the SOV on direct coronal CT scans and also to identify if this distensibility is linked to aging.

From Jan 2009 to Feb 2010, we retrospectively reviewed contrast-enhanced CT scans of the orbit in 517 patients (261 males, 256 females; age range, 7-82 years; mean age, 46 years) who underwent CT for evaluating various ophthalmologic problems. The patients with the lesions that might compromise the drainage through the SOV, eg marked thyroid orbitopaphy, large orbital tumor, orbital varix, dural AV fistula, and cavernous sinus thrombosis were excluded from the study. Direct coronal CT scans were obtained with the patients in supine position with the neck hyperextended. We compared the SOV diameter on axial CT scans with that on direct coronal CT scans, measured at the approximately same position in all patients, ie, midway through the intraconal space between the superior rectus muscle and the optic nerve. Correlation between the degree of SOV distension and the patients’ age were performed by Pearson correlation analysis.

The mean diameters of both of the right and left SOVs on axial and direct coronal CT scans were 1.2 mm and 2.5 mm, respectively. The maximum diameters of the right and left SOVs on axial CT scans were 2.7 mm and 2.4 mm, respectively, while those on direct coronal CT scans were 6.8 mm and 7.1 mm, respectively. The mean differences in the SOV diameters between axial and direct coronal CT scans were 1.1 mm on both sides with the maximum differences being 5.3 mm in the right and 5.9 mm in the left. There was no significant correlation between the degree of SOV distension and the age of the patients.

The SOVs can be dilated normally with various degrees on direct coronal CT scans. The degree of distension of the SOVs seems to be unrelated to aging. Knowledge of this finding would prevent the radiologist from the overdiagnosis of orbital varix.

Knowing that the superior ophthalmic veins can be dilated normally with various degree on direct coronal CT scans would avoid the overdiagnosis of orbital varix.

Lee, D, Kim, E, Kim, H, Lee, H, Kim, S, Kim, Y, The Superior Ophthalmic Vein: The Degree of Distensibility on Direct Coronal CT of the Orbit.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9010235.html