Imaging of the Internal Carotid Artery: The Dilemma of Total versus Near Total Occlusion

Abstract

Assuming US is the initial imaging examination, when occlusion is diagnosed, MR angiography can depict it. If occlusion is confirmed, no further imaging is necessary. US performed well in helping to differentiate vessels with focal severe stenosis from those with diffuse disease. MR angiography added little in this group. Catheter angiography remains beneficial for vessels with diffuse nonfocal narrowing.

Carotid Near-Occlusion: A Comprehensive Review, Part 1—Definition, Terminology, and Diagnosis

“…Images from Sekhar et al can be called "near-occlusion with full collapse." "Pseudo-occlusion" has been used for the appearance of a collapsed artery, [1][2][3][4][5][6][7][8][9]11,[13][14][15][16][17][18][19][20][45][46][47][48][56][57][58][59][60][61][62][65][66][67][68][69][70] but also quite literally when diagnosis changed from occlusion to patent after re-review (not necessarily with distal collapse. 10,12,55,63,64,81 String Sign.…”

“…1 Various terms have been used to describe near-occlusion, which can mislead students or those doing literature searches: near-occlusion (or "near total occlusion" [45][46][47][48][49][50][51] ), pseudo-occlusion, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]43,45,47,48,50-70 string sign, 1-5,7,9-13,16,18-20,22,24,26,30, 11,12,18,45 99% stenosis, 66 hairline residual lumen, 20,43 and incomplete occlusion. 1 Calculating percentage stenosis for carotid near-occlusion is fallacious, and near-occlusion assessment is advised before measuring for percentage stenosis.…”

“…Perhaps the commonly used additional method, power Doppler, may better detect slow flow, but only 2 small studies analyzed this. 5,17 Adding transoral sonography to also assess distal artery patency at the level of the pharynx shows promising initial findings. 8 Contrast-enhanced sonography might also increase the accuracy, but this has not been evaluated.…”

CT and Ultrasound in the Study of Ulcerated Carotid Plaque Compared with Surgical Results: Potentialities and Advantages of Multidetector Row CT Angiography

“…Moreover, conventional angiography is also associated with an increased risk of thromboembolic events. 19 Consequently, noninvasive techniques, such as ultrasound (US) echo color Doppler (US-ECD), 20,21 MR, 22,23 and CT angiography (CTA) 18,24 have been more and more frequently used to study carotid artery pathology.…”

Window Settings for the Study of Calcified Carotid Plaques with Multidetector CT Angiography

“…The value was calculated by comparing the stenosed segment diameter with the more distal normal one, in which stenosis was absent. Every time a near-occlusion condition 36,37 was detected, the above-described method was not applied; thus these patients were directly included in NASCET V group. In our final analysis, NASCET I (absence of plaque) and NASCET VI (complete occlusion) were excluded.…”