Imaging near orthopedic hardware

Abstract

Over one million total joint replacement surgeries were performed in the US in 2013 alone, and this number is expected to more than double by 2030. Traditional imaging techniques for post-operative evaluation of implanted devices, such as radiography, computerized tomography or ultrasound utilize ionizing radiation, suffer from beam hardening artifact, or lack the inherent high contrast necessary to adequately evaluate soft tissues around the implants, respectively. Magnetic resonance imaging (MRI), due to its ability to generate multi-planar, high contrast images without the use of ionizing radiation is ideal for evaluating peri-prosthetic soft tissues but has traditionally suffered from in-plane and through-plane data misregistration due to the magnetic susceptibility of implanted materials. A recent renaissance in the interest of imaging near arthroplasty and implanted orthopaedic hardware has led to the development of new techniques which help to mitigate the effects of magnetic susceptibility. This paper will describe the challenges of performing imaging near implanted orthopaedic hardware, how to generate clinically interpretable images when imaging near implanted devices, and how the images may be interpreted for clinical use. We will also describe current developments of utilizing MRI to evaluate implanted orthopaedic hardware.

18F-FDG PET for Diagnosing Infections in Prosthetic Joints

“…5,15 CT 16 and magnetic resonance imaging (MRI) using metal artifact reduction sequences may be more accurate, because they can detect soft tissue abnormalities associated with PJI, included among which are periarticular fluid collections, joint effusion, synovitis, lymphadenopathy, and sinus tracts. [17][18][19] The accuracy of these cross-sectional imaging modalities, however, has not yet been widely validated. Granulomatous reactions to wear, the concurrence of adverse local tissue reaction and PJI, and underlying rheumatoid diseases may impede assessment by CT and MRI.…”

Future Perspective of the Application of Positron Emission Tomography-Computed Tomography-MR Imaging in Musculoskeletal Disorders

“…5,15 CT 16 and magnetic resonance imaging (MRI) using metal artifact reduction sequences may be more accurate, because they can detect soft tissue abnormalities associated with PJI, included among which are periarticular fluid collections, joint effusion, synovitis, lymphadenopathy, and sinus tracts. [17][18][19] The accuracy of these cross-sectional imaging modalities, however, has not yet been widely validated. Granulomatous reactions to wear, the concurrence of adverse local tissue reaction and PJI, and underlying rheumatoid diseases may impede assessment by CT and MRI.…”

Advanced MRI Techniques for the Hip Joint: Focus on the Postoperative Hip

“…This results in field inhomogeneities that distort regional anatomy and reallocate signal from its proper position to overlie like frequency spins, generating areas of signal pileup around areas of signal loss [3, 4], with resultant misregistration artifacts in both the slice selection and readout directions during signal encoding [2, 5]. Metallic implants also accelerate proton dephasing, which degrades the periprosthetic signal [6].…”

“…Furthermore, MAVRIC SL, a fusion MAVRIC-SEMAC sequence, merges the high signal-to-noise ratio and resolution associated with the MAVRIC sequence with the slice location selectivity that accompanies the SEMAC sequence. This hybrid sequence can acquire not only proton density– and T1-weighted images but also STIR images, allowing homogeneous fat suppression in the presence of metal [3]. Cross-talk artifacts have presented a challenge when it comes to 3D multispectral imaging, because spectral overlap is necessary to reduce gaps between the aforementioned spectral frequency bins.…”