A multispectral three‐dimensional acquisition technique for imaging near metal implants

TLDR

Metallic implants in bone and joint arthroplasty create severe spatial perturbations of the B0 field, distorting slice‑selection and frequency‑encoding in conventional 2‑D MRI and impeding complication diagnosis. The authors aim to develop a method that acquires multiple 3‑D fast‑spin‑echo images using discrete RF transmission and reception frequency offsets. This approach employs a multi‑acquisition variable‑resonance image combination technique to mitigate magnetic field inhomogeneities. The technique produces composite images free of slice‑plane distortion and with markedly reduced readout‑direction distortion even near metallic implants. Published in Magn Reson Med 61:381–390 (2009) © Wiley‑Liss, Inc.

Abstract

Abstract Metallic implants used in bone and joint arthroplasty induce severe spatial perturbations to the B 0 magnetic field used for high‐field clinical magnetic resonance. These perturbations distort slice‐selection and frequency encoding processes applied in conventional two‐dimensional MRI techniques and hinder the diagnosis of complications from arthroplasty. Here, a method is presented whereby multiple three‐dimensional fast‐spin‐echo images are collected using discrete offsets in RF transmission and reception frequency. It is demonstrated that this multi acquisition variable‐resonance image combination technique can be used to generate a composite image that is devoid of slice‐plane distortion and possesses greatly reduced distortions in the readout direction, even in the immediate vicinity of metallic implants. Magn Reson Med 61:381–390, 2009. © 2009 Wiley‐Liss, Inc.