Leaps in Technology: Advanced MR Imaging after Total Hip Arthroplasty

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Promising outcomes of hip replacement interventions in this era of aging populations have led to higher demands for hip arthroplasty procedures. These require effective methods and techniques for the detection of postoperative outcomes and complications. Based on the presence or absence of radiographic findings, magnetic resonance imaging (MRI) and computed tomography (CT) may be required to detect and further characterize different causes of failing implants. Yet metal-related artifacts degrade image quality and pose significant challenges for adequate image quality. To mitigate such artifacts in MRI, a set of techniques, collectively known as metal artifact reduction sequence (MARS) MRI, were developed that optimize the framework of the conventional pulse sequences and exploit novel multispectral and multispatial imaging methods such as Slice Encoding for Metal Artifact Correction (SEMAC) and Multi-Acquisition Variable-Resonance Image Combination (MAVRIC). Metal-induced artifacts on CT can be effectively reduced with virtual monochromatic reconstruction of dual-energy CT data sets, metal artifact reduction reconstruction algorithms, and postprocessing image visualization techniques.

Section: Metal-related Mri Artifactsmentioning

confidence: 99%

Section: Advanced Techniques Of Mri Metal Artifact Reduction View Angmentioning

confidence: 99%

Metal About the Hip and Artifact Reduction Techniques: From Basic Concepts to Advanced Imaging

Khodarahmi

Isaac

Fishman³

et al. 2019

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“…20 MRI allows for excellent evaluation of osseous, implant, and soft tissue structures, provided that metal artifact reduction techniques are used successfully. 22 Strategies for decreasing metal artifact include imaging at 1.5 T instead of 3 T, employing a wide receiver bandwidth, decreasing slice thickness, and increasing the number of excitations. Inversion recovery fat suppression is superior to frequency selective fat saturation in the presence of metal.…”

Section: Imaging Modalitiesmentioning

confidence: 99%

Imaging of Hip Arthroplasties: Normal Findings and Hardware Complications

Deshmukh

Omar

2019

Hip arthroplasty is a common and largely successful surgical procedure, often used for the treatment of advanced osteoarthritis. Imaging plays a key role in routine postoperative imaging surveillance as well as the evaluation of post-arthroplasty pain. Radiographs are the first-line imaging modality and may be followed by computed tomography (CT), ultrasound, and/or magnetic resonance imaging (MRI). Recent advancements in imaging techniques allow for metal artifact reduction on CT and MRI. A variety of complications can arise in the setting of arthroplasty: mechanical loosening, component wear-induced synovitis and osteolysis, adverse local tissue reaction, infection, periprosthetic fracture, implant dislocation and/or component displacement, tendinopathy, and neurovascular injury. This article reviews normal and abnormal imaging findings of hip arthroplasty.

“…Various artifacts have been described in association with MRI of metal implants. 33 Signal loss occurs because of large intravoxel magnetic field variation and the resultant dephasing. It is also in part due to lack of excitation of those spins that resonate outside the radiofrequency bandwidth.…”

Section: Magnetic Resonance Imaging Artifactsmentioning

confidence: 99%

Dedicated CT and MRI Techniques for the Evaluation of the Postoperative Knee

Khodarahmi

Fishman

Fritz

2018

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Advances in surgical techniques, orthopaedic implant design, and higher demands for improved functionality of the aging population have resulted in a high prevalence of patients with metallic implants about the knee. Total knee arthroplasty, knee-replacing tumor prostheses, and osteosynthesis implants create various imaging artifacts and pose special challenges for the imaging evaluation with computed tomography (CT) and magnetic resonance imaging (MRI). CT artifacts can be effectively mitigated with metal artifact reduction reconstruction algorithms, dual-energy data acquisition with virtual monoenergetic extrapolation, and three-dimensional postprocessing techniques, such as volume and cinematic rendering. Artifacts related to metal implants on MRI can be reduced via optimization of the scan parameters and using advanced techniques such as multi-acquisition variable-resonance image combination, and slice encoding for metal artifact correction.