Detection of carotid artery stenosis and obstruction by cerebral radionuclide angiography.

CA and RA were performed in 140 patients suffering either from TIAs (n = 43; mean age 59 +/- 9.7 years) or from RIND (n = 97; mean age 58 +/- 13 years). Completed stroke was excluded from this study. Criteria of abnormality of RA were determined from a normal control group (n = 100; mean age 37 +/- 17 years). Overall detection rate of extracranial carotid artery lesions of any size was 63% (42:66). False negative results were reviewed. Within the same group of patients, DU was positive in 76%. The addition of RA and DU enhanced the detection rate to 88%. In the subgroup with normal extracranial carotid arteries, RA accounted for 6.7% of false positive results. Intracranially, RA was able to demonstrate a significant asymmetry of perfusion in good correlation with clinical examination in 65% of the cases (91: 140), whereas CA was found positive in only 26% of the patients. It is concluded that RA is best suited for documentation of intracranial carotid artery territory disease and for studying intracranial consequences of extracranial lesions. In contrast, DU is preferred for detection of extracranial lesions. However, the addition of both techniques enhances the power of non-invasive detection of carotid artery stenosis and obstruction.