111In platelet scintigraphy for the noninvasive detection of carotid plaque thrombosis.
OBJECTIVE
Thrombosis on atherosclerotic lesions in the large extracranial arteries is the main cause of embolization in the distal cerebral circulation and thus is involved in the pathogenesis of ischemic stroke. The assessment of biological characteristics of lesions that are predictive of thrombotic complications might help in stratification of the risk for stroke but is currently imperfect.


METHODS
We compared the performance of (111)In-platelet scintigraphy with blood pool subtraction, ultrasound-based tissue texture analyses, and transcranial Doppler techniques in their ability to predict the occurrence of superficial thrombosis or the presence of a lipid pool in carotid artery plaque specimens removed at the time of carotid endarterectomy in 22 patients with unilateral carotid artery stenosis of >70%.


RESULTS
Positivity at (111)In-platelet scintigraphy was present in 8 patients and correctly identified the presence of thrombosis superimposed on a complicated plaque. Neither tissue texture analysis nor emboli detection by transcranial Doppler, performed in 12 patients, significantly identified plaque thrombosis. None of the techniques used were able to detect the presence of a significant lipid pool inside the plaque.


CONCLUSIONS
Indium-platelet scintigraphy is an accurate noninvasive diagnostic tool to detect thrombotic complications in carotid plaques. Prospective studies should assess its ultimate value in risk stratification, possibly to guide the decision of whether to perform endarterectomy in selected patient categories.
Division of Nuclear Medicine, University of Pisa, Pisa, Italy.
G
G
Manca
G
G
Parenti
R
R
Bellina
G
G
Boni
M
M
Grosso
W
W
Bernini
C
C
Palombo
M
M
Paterni
G
G
Pelosi
M
M
Lanza
N
N
Mazzuca
R
R
Bianchi
R
R
De Caterina
D000368:Aged; D015901:Angiography, Digital Subtraction; D001792:Blood Platelets / Q000000981:diagnostic imaging*; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D002341:Carotid Artery Thrombosis / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D015637:Gated Blood-Pool Imaging; D006801:Humans; D007205:Indium Radioisotopes; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D013667:Technetium; D018616:Ultrasonography, Doppler, Duplex; D017585:Ultrasonography, Doppler, Transcranial
D007205:Indium Radioisotopes; D008055:Lipids; D013667:Technetium