Metallic artifacts on MR images of the postoperative spine: reduction with fast spin-echo techniques.
OBJECTIVE
To determine whether the relative insensitivity of T2-weighted fast spin-echo (FSE) techniques to magnetic susceptibility can be exploited to reduce metallic artifacts on images of the postoperative spine and, thus, improve the interpretation of the postoperative study.


METHODS
Three neuroradiologists retrospectively evaluated sagittal T2-weighted conventional spin-echo and FSE images obtained in 15 patients with metallic artifacts from various sources including drill particles from anterior cervical diskectomy, posterior fixation wires, fixation rods or plates, and an inferior vena cava filter. The amount of artifact present and whether these artifacts affected image interpretation were evaluated.


RESULTS
Among the 45 paired evaluations, the artifact was judged to be less apparent with FSE sequences in 39. In eight of 45 evaluations (18%), the interpretation of the area of interest was possible only on the FSE images.


CONCLUSIONS
FSE imaging, especially when performed with shorter echo spacing, increases the amount of T2-weighted information in the presence of metallic artifact because it decreases magnetic susceptibility effects.
Tartaglino
L M
LM
Department of Radiology, Jefferson Medical College, Philadelphia, PA.
Flanders
A E
AE
Vinitski
S
S
Friedman
D P
DP
D016477:Artifacts; D001860:Bone Plates; D001864:Bone Wires; D017586:Diskectomy; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008670:Metals; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion; D013131:Spine / Q000000981:diagnostic imaging* / Q000601:surgery
D008670:Metals