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The purpose of this review is to provide an update on technology related to Transcranial Color Coded Doppler Examinations. Microvascularization (MicroV) is an emerging Power Doppler technology which can allow visualization of low and weak blood flows even at high depths, thus providing a suitable technique for transcranial ultrasound analysis. With MicroV, reconstruction of the vessel shape can be improved, without any overestimation. Furthermore, by analyzing the Doppler signal, MicroV allows a global image of the Circle of Willis. Transcranial Doppler was originally developed for the velocimetric analysis of intracranial vessels, in particular to detect stenoses and the assessment of collateral circulation. Doppler velocimetric analysis was then compared to other neuroimaging techniques, thus providing a cut-off threshold. Transcranial Color Coded Doppler sonography allowed the characterization of vessel morphology. In both Color Doppler and Power Doppler, the signal overestimated the shape of the intracranial vessels, mostly in the presence of thin vessels and high depths of study. In further neurosonology technology development efforts, attempts have been made to address morphology issues and overcome technical limitations. The use of contrast agents has helped in this regard by introducing harmonics and subtraction software, which allowed better morphological studies of vessels, due to their increased signal-to-noise ratio. Having no limitations in the learning curve, in time and contrast agent techniques, and due to its high signal-to-noise ratio, MicroV has shown great potential to obtain the best morphological definition., (Copyright © 2018 by the American Society of Neuroimaging.)

Background: Recent studies suggest that alterations in the cerebrospinal venous system may play a role in multiple sclerosis (MS) and that chronic cerebrospinal venous insufficiency correlates with clinical features of MS patients., Objectives: To evaluate the vascularization of optic nerve (ONr) and measure ONe thickness by color Doppler ultrasonography in MS patients with and without previous optic neuritis (ONe)., Subjects and Methods: We assessed flow variables in the ophthalmic artery, central retinal artery, and central retinal vein and measured the diameter of ONe in 46 relapsing-remitting MS patients and 37 healthy controls (HC). Twenty-two MS patients had previous ONe and 24 MS patients had not. Patients with acute ONe were not included. We examined and compared 63 unaffected and 29 affected eyes of MS patients with 74 control eyes., Results: Regarding flow variables, we did not find any significant difference between HC, MS affected, and unaffected eyes. Comparing ONr diameters, we found a progressive significant thinning of the ONr from HC to MS patients without and with past ONe., Conclusions: We found no significant alteration in the arterial-venous vascularization of both affected and unaffected ONr compared with HC. We demonstrated the possibility to detect ONr atrophy in MS patients., (Copyright © 2012 by the American Society of Neuroimaging.)