Segmentation of wall and plaque in in vitro vascular MR images

The potential of MR for plaque imaging and characterization is huge, due to its high spatial resolution, three-dimensional data acquisition and ability for tissue characterization. One of the major limitations, however, for the widespread use of this technique in large trials is the time consuming postprocessing which is often done on a manual basis. It is well known, that quantification improves reproducibility of imaging results, optimal reproducibility is reached, when only minimal user interference is required. This holds true not only for plaque imaging, but also for the assessment of regional wall motion [1–5] or perfusion [6–8], just to name a few. In this edition of the International Journal of Cardiovascular Imaging, Yang et al. describe a new, mainly automated method for the segmentation of arterial wall layers and plaques. They applied their method in T1-weighted MR images of human ilio-femoral arteries in vitro and determined vessel outline, the lumen, as well as the internal elastic lamina and the external elastic lamina. With their method, they found a mean difference between automatically detected plaque borders and manually drawn borders of approximately one pixel. Such an accuracy may be regarded as sufficient and probably as good as it may get. Before this method can be applied in human in vivo studies, however, several questions remain and need to be shown in future studies.