Ultrasonographic confirmation of carotid artery atheromas diagnosed via panoramic radiography.
Studies have shown that panoramic radiographs can capture images of calcified atheromas in the internal carotid artery (ICA) in some neurologically asymptomatic patients receiving routine dental care. However, the prevalence of these hemodynamically significant lesions--that is, those causing greater than 50 percent vessel lumen occlusion with the consequent heightened risk of stroke--has been evaluated rarely. The purpose of this study was to use Doppler ultrasonography (DUS) to determine the prevalence of large occlusive lesions detected initially via panoramic radiography. Aggressive medical and surgical interventions directed toward these large lesions have been shown to moderate the risk of stroke. The authors analyzed the panoramic radiographs of 1,548 consecutively treated, neurologically asymptomatic dental patients who were 50 years or older. Those with presumptive atheromas underwent DUS for confirmation of the diagnosis and for determination of the degree of stenosis. The radiographs of 65 patients (4.2 percent) showed at least one ICA atheroma. Thirty-eight patients had bilateral opacities and 27 had unilateral opacities. DUS evaluation of the 103 sides of the neck with a radiographically identified atheroma revealed that none of the ICAs were normal, 81 (79 percent) had less than 50 percent stenosis, 18 (17 percent) had 50 to 69 percent stenosis and four (4 percent) had 70 percent or greater stenosis. Four of the ICAs on the 27 sides without calcifications were deemed normal and 23 had less than 50 percent stenosis. These results demonstrate that a subset of patients (15 [23 percent] of 65) with an occult atheroma discovered on panoramic radiography had significant (> 50 percent) levels of ICA stenosis. Dentists should refer all patients with radiographically identified atheromas to a physician for confirmation of the diagnosis and a determination of the magnitude of disease, because antiatherogenic interventions have been shown to prevent a stroke.