ARTIFACTS AND PITFALLS IN MR-IMAGING OF THE ORBIT - A CLINICAL REVIEW

High-resolution magnetic resonance (MR) imaging of the orbit has becom e widely accepted as a valuable diagnostic technique, However, there a re a number of artifacts and pitfalls associated with orbital MR imagi ng, Chemical shift artifacts may be induced by orbital fat or silicone oil used to treat retinal detachment, Motion artifacts are caused pri marily by unavoidable globe motion during imaging, Artifacts due to a nonuniform magnetic field are particularly noticeable at air-tissue in terfaces but may also be caused by incomplete fat saturation or highly magnetic materials near the orbit, Protocol errors may cause artifact s such as saturation, phase wraparound, truncation, shading, and parti al-volume artifacts, This information can be used to improve orbital i mage quality and avoid misinterpretation of image artifacts, Use of fa t saturation, silicone saturation, and careful patient screening for m etal near the eyes and innnd tnk ing the test, the struction to reduce motion can help reduce the occurrence of artifacts, In addition, opti mal imaging technique is essential and should include use of proper su rface coils, plane of section, and pulse sequences.