Article Figures & Data
Figures
- Fig 1.
The relationship between contrast ratio from each MR sequence for plaque imaging and the development of microembolic signals during exposure of the carotid arteries. Dashed horizontal lines denote the cutoff points lying closest to the left upper corners of the receiver operating characteristic curves in predicting the development of MES during exposure of the carotid arteries. The horizontal line denotes the cutoff points lying closest to the left upper corners of the ROC curve in predicting the development of ≥6 MES during exposure of the carotid arteries.
- Fig 2.
ROC curves used to compare accuracy among contrast ratios in each MR image for predicting the development of MES during exposure of the carotid arteries. Pair-wise comparison analysis shows a significantly greater area under the ROC curve for nongated SE compared with AUCs for BB-FSE, MPRAGE, or SI-MRA.
- Fig 3.
Comparisons of contrast ratios in each MR image and the number of MES in patients with MES during exposure of the carotid arteries. In negative binominal regression analysis, CR was associated with the number of MES only in nongated SE. The dashed horizontal line denotes 6 MES as the optimal cutoff point for predicting the development of new postoperative ischemic events.34
- Fig 4.
The relationship between the percentage area of each component in quantitative color-coded MR plaque imaging and the development of MES during exposure of the carotid arteries. The dashed horizontal lines denote the cutoff points lying closest to the left upper corners of the ROC curves in predicting the development of MES during exposure of the carotid arteries.
- Fig 5.
ROC curves used to compare accuracy among percentage areas of each component in quantitative color-coded MR plaque imaging for predicting the development of MES during exposure of the carotid arteries. Pair-wise comparison analysis shows significantly greater AUCs for hemorrhage or fibrous tissue than for lipid/necrosis.
- Fig 6.
Four kinds of MR plaque images (upper) and quantitative color-coded MR plaque image (right lower) in the symptomatically stenosed (95%) right internal carotid artery of a 72-year-old man showing MES during exposure of the carotid arteries in endarterectomy. A larger FOV image (left lower) indicates anatomic relationships among each vessel (arrow, internal carotid artery; yellow circle, lumen of the internal carotid artery filled with plaque; single arrowhead, internal jugular vein; double arrowhead, external carotid artery; and white square, FOV identical to that of other images). Signal intensities of the plaque in the internal carotid artery (arrows) relative to those of the sternocleidomastoid muscle (asterisks) are, in ascending order, BB-FES, MPRAGE, SI-MRA, and nongated SE. The plaque comprises mainly red and partially yellow areas on the color-coded MR plaque image. On the basis of contrast ratios, hemorrhage, lipid/necrosis, and fibrous tissue are displayed as red, yellow, and green, respectively.
Tables
Risk factors related to the development of MES during exposure of the carotid arteries
Factors Development of MES P Value Yes (n = 23) No (n = 57) Age (yr) (mean) 69.8 ± 5.6 69.2 ± 7.3 .5507 Male sex 22 (95.7%) 55 (96.5%) >.9999 Hypertension 18 (78.3%) 46 (80.7%) >.9999 Diabetes mellitus 6 (26.1%) 20 (35.1%) .5989 Dyslipidemia 7 (30.4%) 14 (24.6%) .5867 Symptomatic lesions 19 (82.6%) 31 (54.4%) .0223 Degree of ICA stenosis (%) (mean) 86.8 ± 9.3 88.8 ± 8.1 .4913 Length of stenotic lesion (mm) (mean) 52.2 ± 11.3 54.3 ± 11.9 .4003 Height of distal end of stenotic lesion relative to cervical vertebra (mean) 2.8 ± 0.9 2.9 ± 0.8 .6046 Tortuosity of stenotic lesion (mean) 107.0° ± 23.3° 111.1° ± 24.0° .4755 Ulceration of stenotic lesion 12 (52.2%) 15 (26.3%) .0372
