Optic nerve sheath diameter measurement by ultrasound after moderate traumatic brain injury

Abstract

We recently reviewed an article by Torabi et al. [1] in your journal concerning evaluation of optic nerve sheath diameter (ONSD) by ultrasound after moderate traumatic brain injury [1]. The article is noteworthy for its intriguing idea, but we would like to raise several concerns.In the study, the authors utilized a 7.5 MHz linear probe to perform ONSD measurements in axial and coronal sections, most likely using the ultrasound B-scan technique. The B scan is very

Carotid-Cavernous Fistulas: The Utility of Ocular Echography in Their Differentiation [Letter]

“…3 However it has also been suggested to rapidly detect and differentiate between dural and direct CCFs since late 1970s with the so called standardized echography by KC Ossoinig 4 utilizing B scan together with an A scan with an 8 MHz non-focused probe with S-shaped amplification that provides more accurate information and measurements of structures than the B-scan technique alone. 5 In case of direct CCFs, ultrasound detects dilation of the superior ophthalmic vein with pulsation of the walls, vertical veins, and sometimes the inferior ophthalmic vein due to arterialization and increased flow within these vessels. A low and regular reflectivity, weak sound attenuation with an angle k lower than 30°, and the presence of rapid spontaneous movements in the lumen of these vessels indicating flow arterialization.In cases of dural CCFs, A-scan ultrasound shows thickening of all orbital structures, particularly the extraocular muscles and optic nerve sheaths due to venous congestion in the orbit.…”