CT of the Hip Prosthesis: Appearance of Components, Fixation, and Complications

Abstract

Multidetector computed tomography (CT) is an excellent way to supplement the radiographic evaluation of problematic hip prostheses. Multidetector CT is well suited for assessing periprosthetic bone, determining precise acetabular cup position, and evaluating periprosthetic fluid collections or ossified masses. Metal implants pose a number of challenges in the performance and interpretation of CT examinations. However, metal artifacts can be minimized by decreasing the detector collimation and pitch, increasing the kilovolt peak and milliampere-seconds, and using appropriate reconstruction algorithms and section thickness. Image interpretation requires a basic understanding of hip reconstruction and hip implants, as well as use of a systematic method of analysis that incorporates prior radiographic findings and CT findings. Radiologists must be familiar with the normal and abnormal CT appearances of hip prostheses and be able to recognize common complications on CT scans.

Reduction of Metal Artifacts from Hip Prostheses on CT Images of the Pelvis: Value of Iterative Reconstructions

“…In computed tomography (CT), the metal of hip prostheses causes considerable artifacts due to photon starvation and beam hardening (2). Thus, visualization of both adjacent and distant tissue, including pelvic organs, may typically be limited in patients with hip prostheses, which impairs the diagnostic confidence of the examination and potentially results in missed findings (3).…”

Metal artifact reduction (MAR) based on two-compartment physical modeling: evaluation in patients with hip implants

“…Although technical improvements like integrated circuit detectors and iterative reconstructions have led to an improved image quality in CT while radiation dose could be markedly reduced, artifacts due to implanted metal-containing materials such as endoprostheses and coils are an enduring challenge in CT examinations and University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany can hamper clinical diagnosis (1)(2)(3). Besides image interpretation, artifacts from high-density objects represent a severe problem for radiation therapy planning and attenuation correction in positron emission tomography CT (PET-CT) (4)(5)(6)(7).…”

Visibility of bony structures around hip prostheses in dual‐energy CT: With or without metal artefact reduction software

“…In our institution, among the total 55 hip joints with total hip replacement that underwent pelvic bone GSI‐DECT, only seven hip joints of seven patients had a metallic prosthesis made of cobalt chrome alloy. It is well known that titanium and cobalt chrome alloy induce a different degree of artefact . Therefore, we excluded patients who had a metallic hip prosthesis made of cobalt chrome alloy.…”

“…In addition, the appearance of multidetector CT can provide better images around the prosthesis with high-resolution images reformatted in any plane. [5][6][7] When orthopaedic metallic implants are evaluated on the CT, the metal-related artefact is a major distraction.…”