In our present study we have demonstrated that measuring IMT in
postmortem arterial specimens by US is a reliable and reproducible method, which could be used for US standardization in subsequent studies. Hence, in vitro US measured IMT could be used to develop, improve, compare or validate new imaging techniques (e.g. fast three dimensional imaging techniques), automated IMT measurement algorithms, or new softwares for ultrasound methods. Carotid IMT is strongly determined by genetic factors acting independently of traditional cardiovascular risk factors [35] and [36]. A heritability range of 20–40% has been estimated by studies in unselected subjects, twins, and people with type II diabetes [36], [37], [38], [39] and [40]. Genes related to hemostasis, lipid and lipoprotein levels, extracellular matrix remodeling, antioxidation, renin–angiotensin system, endothelium function, Sirolimus Olaparib inflammation have been associated with
carotid IMT changes [34] and [41]. On the other hand, laminar flow and oscillatory shear stress trigger diverse local endothelial responses and altered gene expressions and result in an atherogenic phenotype [26], [42], [43] and [44] which may vary in different carotid segments with a possible impact on IMT. Our results implicate that in vitro US including IMT provide valuable information about autopsied arterial specimens. These, afterwards, can be stored and made available in tissue banks for a wide IKBKE range of ‘-omics’ investigations. In addition, in vitro US of arterial specimens could serve as a guide to identify the most appropriate region of an intact autopsied vascular tissue for histological sampling. Furthermore, Liao et al. (2008) applied the gene risk score (GRS) to estimate a cumulative effect of genes significantly associated with IMT and emphasize
the importance of future gene-IMT association studies on different populations. The use of the GRS may simplify an assessment of multiple gene effects in complex diseases and may provide a better estimate of individual susceptibility to atherosclerosis [26]. The accuracy and utility of GRS can possibly be improved by including an US artifact free postmortem IMT measurements of different parts of arterial wall (e.g. ‘far wall, near wall’, etc.). GRS combined with IMT could improve the precision and reliability of prognosis determination models for a complex disease like atherosclerosis. In the present study we measured arterial IMT applying in vitro US and compared it to in vivo determined IMT, histological IMT and average arterial wall thickness. We demonstrate that for microscopic IMT determination purposes cutting and processing frozen arterial sections after in vitro US is a suitable histological technique which has advantages compared to use of formalin fixed paraffin embedded (FFPE) slides.