NEURORADIOLOGY


Case 35 :
A 60-year-old presents with blunt eye trauma, of 2 weeks duration. Membrane is noted on B scan, with undulating movements on eye movements. What is the diagnosis?

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Fig 1.

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Diagnosis

Posterior vitreous detachment with subvitreal collection, and minimal vitreous hemorrhage

Discussion

Vitreous hemorrhage is a common finding in patients with trauma. US is useful in detecting the density and location of hemorrhage. In fresh, mild hemorrhage, dots and short lines are displayed on B-scan and a chain of low amplitude spikes is found on A-scan. The more dense the hemorrhage, more opacities are seen on B-scan and higher is their reflectivity on A-scan. If the hemorrhage spreads diffusely, it creates scattered low amplitude echoes. Organization of blood creates interfaces that may have a pseudomembranous appearance on B-scan and variable reflectivity on A-scan. Variable degrees of posterior vitreous detachment (PVD) usually accompany vitreous hemorrhage. On B-scan, detached vitreous is usually smooth and may be thick posteriorly when blood is layered along its surfaces. Reflectivity in cases of PVD varies from extremely low as in the normal eye to extremely high as in the case of dense hemorrhage. Kinetic US typically shows an undulating after-movement on B-scan, which normally allows the PVD to be distinguished from less mobile retinal and choroidal detachments. On A-scan, PVD typically exhibits marked horizontal and vertical spike after movement. However, there are situations in which the acoustic behavior of PVD is similar to retinal detachment, so the distinction of PVD from retinal detachment may be quite challenging


Dr. Rahul Sachdev, BR Diagnostics, Delhi