2 research outputs found
Combined use of transcranial magnetic stimulation and metal electrode implants: a theoretical assessment of safety considerations
Accuracy of a novel risk index combining degree of stenosis of the carotid artery and plaque surface echogenicity.
Background and Purpose—The purpose of this study was to determine the accuracy of a risk index in symptomatic or
asymptomatic carotid stenoses.
Methods—Consecutive patients presenting 50% to 99% carotid stenoses were included. A semiautomated gray scale-based
color mapping (red, yellow, and green) of the whole plaque and of its surface was achieved. Surface was defined as the
region located between the lumen (Level 0) and, respectively, 0.5, 1, 1.5, and 2 mm. Risk index was based on a
combination of degree of stenosis and the proportion of the red color (reflecting low echogenicity) on the surface or on
the whole plaque.
Results—There were 67 (36%) symptomatic and 117 (64%) asymptomatic carotid stenoses. Risk index values were higher
among symptomatic stenoses (0.46 mean versus 0.29; P,0.0001); on receiver operating characteristic curves, risk index
presented a stronger predictive power compared with degree of stenosis or surface echogenicity alone. Also, in a
regression model including age, gender, degree of stenosis, surface echogenicity, gray median scale of the whole plaque,
and risk index, risk index measured within the surface region located at 0.5 mm from the lumen was the only parameter
significantly associated with the presence of symptoms (OR, 4.89; 95% CI, 2.7– 8.7; P50.0000002). The best criterion
to differentiate between symptomatic and asymptomatic stenoses was a risk index value .0.36 (sensitivity and
specificity of 78% and 65%, respectively).
Conclusions—Risk index was significantly higher in the presence of symptoms and could therefore be a valuable tool to
assess the clinical risk of a carotid plaque. (Stroke. 2012;43:1260-1265.