Carotid CT-angiography: low versus standard volume contrast media and low kV protocol for 128-slice MDCT

Abstract

Availability and utilization of computed tomography angiography has been increasing recently. We aimed to assess the effectiveness of low amount of contrast media and low kV value in order to reduce possible side effects of contrast media and to provide optimization of kV value in the evaluation of the carotid artery with multi-detector computed tomography angiography. Forty one patients were randomized into two groups. Contrast media was administered at a dose of 1 ml/kg in group A patients and of 0.5 ml/kg in group B patients. kV value of 120 in group A and 100 in group B were chosen. Bolus tracking technique was used. Attenuation values of certain arterial segments were measured, and values over 200 HU were considered as significant. North American Symptomatic Carotid Endartherectomy Trial criteria were utilized in the evaluation of stenosis. Image quality in arterial segments of all cases was found to be sufficient for diagnosis. Arterial attenuation values were found to be higher in group B than group A. When compared separately in all arterial segments, there was no statistically significant difference between the groups. For stenosis, 615 arterial segments were evaluated. Moderate stenosis in eight segments and severe stenosis in three segments were identified in group A. Occlusion in three segments, severe stenosis in three segments, and moderate stenosis in 25 segments were detected in group B. Better image quality can be obtained, and the amount of contrast media can be reduced using low kV technique in carotid artery multi-detector computed tomography angiography examination.