Values Of CTA Delayed Scan In The Diagnosis Of Carotid Plaque

ObjectiveTo evaluate the value of CT angiography(CTA)delayed scan in detecting and diagnosing carotid plaque,aiming at providing more clues for the prevention of ischemic stroke.Methods65 patients with carotid plaques were included and underwent CTA scan.Extra two delayed phases(40s and 60 s after contrast injection)were obtained from patients after the conventional arterial phase was completed.The quality of the images was scored according to the clarity of the plaque contour,the plaque thickness was measured in three phases.The image scores and the thickness of plaques in different sizes were compared in each phase.ResultsThe 40 s and 60 s delayed images showed clearer plaque contour than the arterial images,and could distinguish the outer membrane of the vessel wall from the surrounding fat,muscle and vessels.For the image scores in the small or moderate plaque,it was higher in the delayed phase(40s and60s)than the arterial phase(P < 0.01),while there was no statistic difference between 40 s and 60 s delayed phase(P > 0.05);In addition,the thickness of the small plaque was thicker in delayed phase(40s and 60s)than that in arterial phase(P < 0.05),while there was no significant plaque thickness difference in three phases between the moderate plaque and large plaque(P > 0.05).ConclusionCTA delayed scan can show the plaque contour and composition more clearly and help measure the plaque thickness more accurately,which has a significant advantage in detecting and diagnosing early carotid plaque.