Application of Basic Physics Principles to Clinical Neuroradiology: Differentiating Artifacts From True Pathology on MRI

Abstract

MRI is one of the most commonly used techniques in neuroradiology. Unfortunately, MRI is prone to image distortion and artifacts that can be difficult to identify. Using the provided case illustrations, practical clues, and relevant physical applications, radiologists may devise algorithms to troubleshoot these artifacts.

Synthetic MRI for Clinical Neuroimaging: Results of the Magnetic Resonance Image Compilation (MAGiC) Prospective, Multicenter, Multireader Trial

“…5,[15][16][17][18] Synthetic imaging exhibited characteristic hyperintense artifacts in FLAIR views, corroborating previous reports that further work will be necessary before synthetically generated FLAIR views can fully replace conventional FLAIR in practice. 5,6 While FLAIR artifacts contributed to lower overall image quality scores (because all views were considered in this composite primary end point), the overall impact of FLAIR artifacts on diagnosis was inherently limited by the nature of the synthetic views, in which immediate cross-comparison with other contrast views is possible.…”

Artifacts in Magnetic Resonance Imaging

“…Apart from these three groups of artifacts mentioned above, we may also be forced to deal with artifacts, the occurrence of which indicates a failure of the MRI system [ 3 ], e.g. many a time we dealt with artifacts that indicated the failure of coils or the ones that occurred during GRE/T2* sequence and informed us about the failure of the magnet cooling system.…”

“…They appear as multiple, alternating bright and dark lines – “ringing”. They can be misinterpreted as a syrinx in the spinal cord ( Figure 1 ) [ 3 ] or a meniscal tear in the knee.…”

“…Aliasing artifacts occur when the anatomical structures located outside the field of view are mapped at the opposite end of the image. One can eliminate them by increasing the field of view (FOV) [ 3 ] ( Figure 7A, 7B ).…”

“…They tend to by less prominent on T1-weighted images than on T2-weighted images. Interestingly, these artifacts have been used as a diagnostic aid [ 3 ], to confirm the presence of fat within lesions, e.g. in adrenal adenomas (Dual echo sequences/out-of-phase images – Figure 8A ) or to accentuate the fat-water interfaces at visceral margins Figure 8B ), thus helping in the evaluation of peripheral tumors for possible extravisceral extension [ 5 ].…”