[Evaluation of atherosclerotic carotid plaque composition with magnetic resonance imaging using different sequences].

OBJECTIVE

To evaluate the capability of magnetic resonance imaging (MRI) using different sequences in displaying atherosclerotic carotid plaque composition.

METHODS

Thirty-five patients received pre- and post-contrast carotid MRI examination on a 3.0T scanner. TOF, T(1)W, T(2)W, PDW and CE-T(1)W were used for identifying the positive and negative cases for the plaque composition (lipid-rich necrotic core, intraplaque hemorrhage and calcification), and their respective sensitivity, specificity and Cohens κ with 95% CI for displaying the components of the plaques were calculated.

RESULTS

A total of 74 plaques were found in the 35 patients, and after exclusion of 6 plaques for a thickness below 3 mm, 68 plaques were included for the analysis. Lipid-rich necrotic core were found in 57 plaques, intraplaque hemorrhage in 30 plaques, and alcification in 43 plaques. CE-T(1)W was the optimal sequence for displaying lipid-rich necrotic core with a sensitivity of 100%, specificity of 90.9%, and κ value of 0.944. Both T(1)W and TOF reliably showed the intraplaque hemorrhage, but the former had a greater sensitivity (100%), specificity (92.1%), and κ value (0.911). Of all the 5 sequences, TOF was the best to show calcification with high sensitivity (100%), specificity (92%), and κ value (0.936).

CONCLUSION

CE-T(1)W is the best sequence to show lipid-rich necrotic core with high sensitivity and specificity. T(1)W and TOF show a high level of agreement with the standard to show the intraplaque hemorrhage. TOF is more sensitive and accurate than the other sequences in displaying calcification. The combination of T(1)W, TOF and CE-T(1)W allows accurate evaluation of each component of the plaque.