Effects of iodinated contrast media on common carotid and brachial artery blood flow and wall shear stress

Abstract

The aim of our study was to evaluate the effect of the intravenous contrast media iomeprol on wall shear stress, blood flow and vascular parameters in the common carotid and brachial artery. Thirty outpatients undergoing thoracic or abdominal spiral CT scans were studied. The internal diameter and flow velocity of the common carotid and brachial artery were evaluated by ultrasound, and blood viscosity was measured before and after low osmolality iomeprol (Iomeron 350) injection. The wall shear stress, blood flow and pulsatility index were calculated. To test the differences between groups, the Wilcoxon rank test and Mann Whitney U test were applied. Blood viscosity decreased slightly, but significantly after contrast media (4.6+/-0.7 vs. 4.5+/-0.7 mPa.s, P = 0.02). Contrarily, blood flow and wall shear stress did not change in the common carotid artery, but significantly decreased in the brachial artery (0.9+/-0.4 vs. 0.6+/-0.3 ml/s, P < 0.0001, and 41.5+/-13.9 vs. 35.3+/-11.0 dynes/cm2, P < 0.002, respectively), whereas the pulsatility index significantly increased in the brachial artery (5.0+/-3.3 vs. 7.5+/-5.3, P < 0.001). Iomeprol injection causes blood flow and wall shear stress reduction of the brachial artery; the rise in the pulsatility index suggests an increase in peripheral vascular resistance. Further investigation is needed to evaluate whether these modifications can be clinically relevant.

The Evaluation of Endothelial Functions in Patients with Celiac Disease

“…Cardiovascular risk factors are more associated with microvascular endothelial dysfunction than with macrovascular endothelial dysfunction. [17][18][19][20][21][22][23] This leads to the hypothesis that small vessels become affected earlier by atherosclerosis compared to large vessels. Microvascular function can be evaluated by pulse arterial tonometer (PAT) and shear stress test.…”

Quantitative Myocardial Perfusion with Dynamic Contrast-Enhanced Imaging in MRI and CT: Theoretical Models and Current Implementation

“…The diffusion constants for MRI and CT contrast agents are roughly similar: 2.7 × 10 −2 m 2 /s for gadolinium dimeglumine, and 2.5 × 10 -2 m 2 /s for iohexol [ 13 , 14 ]. Although the nonionic iodine contrast agents typically have a much higher viscosity compared to gadolinium, neither CT nor MRI contrast agents have significant effects on the viscosity of the blood stream [ 15 , 16 ]. Gadolinium-based contrast agents have limited linearity of contrast enhancement to contrast concentration, with higher dose resulting in blood signal saturation [ 17 , 18 ].…”