MR imaging of soft tissues adjacent to orthopaedic hardware: Techniques to minimize susceptibility artefact

Eustace, Stephen; Goldberg, Ronald P.; Williamson, Daniel; Melhem, Elias R.; Oladipo, O.; Yucel, E K; Jara, Hernán

doi:10.1016/s0009-9260(97)80250-4

Cited by 54 publications

(36 citation statements)

References 7 publications

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“…Some techniques to minimize the susceptibility artifact were used consistently for all of the scans (1,(11)(12)(13). The long axis of the metal component was aligned with the frequency encoding axis because this is the direction in which the field distortions are the most prominent.…”

Section: Discussionmentioning

confidence: 99%

Quantitative evaluation of metal artifact reduction techniques

Kolind

MacKay

Munk

et al. 2004

Magnetic Resonance Imaging

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Purpose: To develop a technique to quantify artifact, and to use it to compare the effectiveness of several approaches to metal artifact reduction, including view angle tilting and increasing the slice select and image bandwidths (BWs), in terms of metal artifact reduction, noise, and blur. Materials and Methods:Nonmetallic replicas of two metal implants (stainless steel and titanium/chromium-cobalt femoral prostheses) were fabricated from wax, and MR images were obtained of each component immersed in water. The differences between the images of each metal prosthesis and its wax counterpart were measured. The contributions from noise and blur were isolated, resulting in a measure of the metal artifact. Several off-resonance artifact reduction techniques were assessed in terms of metal artifact reduction capability, as well as signal to noise ratio and blur.Results: Increasing the image BW from Ϯ16 kHz to Ϯ64 kHz was found to reduce the artifact by an average of 60%, while employing view angle tilting (VAT) alone was found to reduce the artifact by an average of 63%. The metal artifact reduction sequence (MARS), which combines several susceptibility artifact reduction techniques, resulted in the least amount of image distortion, reducing the artifact by an average of 79%. Conclusion:The results indicate that while VAT alone (with an image BW of Ϯ16 kHz) resulted in the smallest amount of total energy and no reduction in the signal-tonoise ratio compared to a conventional spin-echo pulse sequence, MARS resulted in significantly less artifact and dramatically less blur. IMAGE DISTORTIONS caused by differences in magnetic susceptibility have long been a problem in clinical imaging, especially in the presence of metal prostheses. Several techniques are commonly used to reduce the severity of metal susceptibility artifact, including simple concessions such as increasing the frequency encoding bandwidth (BW), or orienting the long axis of the metal along the frequency encoding direction (1). A clever technique still not in common usage is view angle tilting (VAT) (2), which has been demonstrated to be clinically useful for reducing the distortion in images when imaging patients with metal implants (3-5) and during interventional MRI where inserted needles distort the local magnetic field (6). VAT results in a marked reduction in the severity of the metal susceptibility artifact, and can be employed without increasing the imaging time. Unfortunately, it introduces blurring, and only reduces the artifact in one direction. These deficiencies are lessened in the metal artifact reduction sequence (MARS), which involves VAT and increased slice select and image BWs. The effectiveness of MARS in reducing susceptibility artifacts in a clinical scan is illustrated in Fig. 1.It is difficult to evaluate quantitatively the competence of a given metal artifact reduction technique. Each method has drawbacks that can mask its ability to reduce metal artifact, and it is necessary to quantify the disadvantages as well as the advantages ...

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Section: Discussionmentioning

confidence: 99%

Quantitative evaluation of metal artifact reduction techniques

Kolind

MacKay

Munk

et al. 2004

Magnetic Resonance Imaging

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“…These sequences, which are based on view angle tilting, smaller interecho spacing, increased readout bandwidth and frequency-encoding direction oriented away from the tissues of interest, can conveniently be used in conjunction with any spin-echo sequence and requires minimal additional imaging time. [6][7][8][9][10][11][12][13][14][15] Despite this, MR imaging in MoM hip replacements has been relatively unexplored and the purpose of this study is to show that MRI is feasible in patients with MoM hips and to provide an insight into the MR imaging features of the various complications associated with MoM hips.…”

Section: -7mentioning

confidence: 99%

Magnetic Resonance Imaging of Metal on Metal Implants: A Breakthrough

Pilania¹,

Jankharia²

2014

Nep J Radiology

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Background: Metal-on-metal (MoM) hip replacement, a durable alternative to conventional metal -on-polyethylene hip replacement, is increasingly common nowadays. There is a 4-8% incidence of pain and complications which usually go undetected on radiographs. MRI has a vast potential for early diagnosis in these cases. Aim: To evaluate the feasibility of MR imaging in MoM hips and to review the MR imaging features of various complications associated with metal on metal hip implants. Materials and Methods: 41 patients with 52 replaced hips using MoM prostheses underwent MRI on a 1.5T scanner using standard clinical protocols optimized to minimize metallic susceptibility artifact, known as metal artefact reduction sequences (MARS). A standardized reporting was done with specific comment on periprosthetic osteolysis, loosening, periprosthetic soft tissue mass, gluteal muscle atrophy, iliopsoas atrophy, muscle edema, muscle/ tendon tear and lymphadenopathy. Results: Diagnostic images were obtained in all patients. Of the 52 hips, 32 had total hip replacement (THR) and 20 had resurfacing. The following abnormalities were found. Periprosthetic osteolysis (5), Periprosthetic soft tissue mass (24), Gluteal muscle atrophymoderate to severe (15), Iliopsoas atrophy (15), Muscle edema (0), Muscle / tendon tear (0), Lymphadenopathy (5). Conclusion: MRI on a 1.5T scanner is a viable technique to image the MoM hip and shows well the various complications associated with post arthroplasty hips.

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“…1,2) However, MRI near metallic implants is inhibited by severe artifacts, since metallic implants, such as stainless steels, CoCr alloys, and Ti alloys, become magnetized in the intense magnetic field of the MRI instrument.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Mechanical Properties of Large-Scale Ingots of the Zr-1Mo Alloy

et al. 2015

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A large-scale ingot of Zr-1Mo alloy was produced for industrial manufacturing to investigate whether it is possible to produce an ingot with homogeneity. The homogeneous ingot with a chemical composition of Zr-1 mass%Mo was prepared successfully. The microstructure, mechanical properties, and magnetic susceptibility were evaluated. The microstructure showed a coarse colony structure of a plate-like ¡ phase and a thin ¢ phase. An ½ phase precipitation was observed in the ¢ phase. Elongation of 23% and magnetic susceptibility of 12.4 © 10 ¹9 m 3 kg) were achieved. We found that it is possible to produce a homogeneous large-scale ingot of Zr-1Mo with high elongation and low magnetic susceptibility.

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MR imaging of soft tissues adjacent to orthopaedic hardware: Techniques to minimize susceptibility artefact

Cited by 54 publications

References 7 publications

Quantitative evaluation of metal artifact reduction techniques

Quantitative evaluation of metal artifact reduction techniques

Magnetic Resonance Imaging of Metal on Metal Implants: A Breakthrough

Microstructure and Mechanical Properties of Large-Scale Ingots of the Zr-1Mo Alloy

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