Carotid plaque morphology: correlation of duplex sonography with histology

This study attempted to determine whether images obtained during preoperative duplex scanning correlated with histologic studies of carotid endarterectomy plaque and, therefore, might be useful in subsequent studies of the importance of plaque morphology and intraplaque hemorrhage. Forty-six endarterectomy specimens from 44 patients with satisfactory preoperative images were evaluated. The plaques were marked for orientation at the time of removal, and each plaque was imaged by duplex scanning in a saline bath. Magnification radiographs were made. Specimens were embedded in paraffin and slices 6 mu thick were made for staining with hematoxylin and eosin, Masson's trichrome, a modified Verhoeff-vanGieson stain, and von Kossa's stain. Overall, correlation between the preoperative images and the histologic specimens were good to excellent in 42 of 46 specimens. Scanning did not identify three cases of extensive recent intraplaque hemorrhage, however, and one instance of plaque calcification was missed. We conclude that duplex images correlate well with histologic studies except in some cases of recent intraplaque hemorrhage. Duplex imaging is valuable in the correlation of plaque morphology with symptoms for long-term studies. The accuracy of the technique may be improved by using post-processing on static images and in vitro scanning of endarterectomy specimens.