Artifacts associated with MR neuroangiography.

Neurovascular MR angiography (MRA) is rapidly gaining greater clinical acceptance. To provide functional information, novel techniques of acquisition, information processing, and display are used, generating a new set of artifacts. The purpose of this paper is to outline the causes, provide examples, and note clinical problems associated with MRA artifacts by grouping them into six common types: 1) poor visualization of small vessels, 2) overestimation of stenosis, 3) view-to-view variations, 4) false positives, 5) false negatives, and 6) vessel overlap. This in turn will lead to four generalized solutions: 1) optimize acquisition parameters, 2) edit volume boundaries before performing maximum intensity projection reconstructions, 3) refer to the individual source images, and 4) use alternative image processing. By organizing and simplifying both clinical problems and solutions into major categories, a greater understanding of the current clinical indications and the overall goals of MRA can be achieved.