Generally, using precise semantics is fundamental to guarantee the reliability of automated data processing, as well as the consistency of information recorded in databases, and their meaningful statistical exploitation. In medicine, this issue has been addressed for many years using standard terminologies such as MeSH or SNOMED. In medical imaging, and especially in the field of Computer Assisted Detection (CAD), information semantics is defined through DICOM Structured Reports that organise relevant information in reference to terminological resources specified in the DICOM standard (DICOM Part 16). This course explains the limitations of this approach, as well as the added value that could be brought in the future by semantic web technologies and especially ontologies. This added value concerns primarily: (1) more effective decision support, thanks to the more precise definition of involved information, e.g. the quantitative markers extracted from the images, (2) enhanced possibilities regarding integration of data from various institutions, e.g. in the context of large clinical trials, or for data mining in the context of translational research and (3) enhanced possibilities in terms of database querying, thanks to the use of the knowledge embedded in referred ontologies (e.g. properties of "is-a" and "part-of" relationships). The presentation will introduce the basic ideas There have been considerable advances in the imaging tools available for imaging the supra aortic vessels, specifically the carotid arteries. Developments ranging from rotational DSA (allowing for accurate delineation of vascular disease) to improvements in CTA and MRA (particularly Gadolinium enhanced studies) have greatly improved our diagnostic armamentarium. In addition there is increased understanding that atheromatous disease localised to the carotid bifurcation is only part of the problem with cerebrovascular disease. Increased coverage of the arch and intracranial circulation are becoming increasingly important requiring greater spatial coverage. In the future imaging of the wall components may become important. For the moment, however, management remains dependent on the accurate assessment of luminal stenosis. The greatest evidence suggests that contrast-enhanced MRA is the investigation of choice. However, CTA is extremely popular especially with clinicians, particularly as it allows algorithms for including or excluding calcification. There is a lesser evidence base, although the relentless progress of technology such as dual beam techniques makes it difficult to provide timely evidence. There are pros and cons for all methodologies, which will be addressed.