Jiang Du1,
Kelly Borden1, Eric Diaz1, Mark Bydder1, Won
Bae1, Shantanu Patil2, Graeme Bydder1,
Christine Chung1
1Radiology, University of California,
San Diego, CA, United States; 2Shiley Center for Orthopedic
Research and Education, La Jolla, CA, United States
Magnetic
resonance imaging (MRI) near metal implants suffers from severe artifacts due
to large metal-induced field inhomogeneities. The steep field gradients near
metal implants result in increased intra-voxel dephasing and a much shortened
T2*. Clinical gradient echo (GE) sequences suffer from large signal loss.
Spin echo (SE) type sequences only partly refocus the dephased spins,
resulting in spatially dependent signal voids and pile-ups. Here we present a
3D ultrashort TE (UTE) sequence which employs short hard pulse excitation and
3D radial sampling with a nominal TE of 8 s to image metallic implants with
markedly reduced artifact.