Diagnostic accuracy of 99mTc-antigranulocyte SPECT/CT in patients with osteomyelitis and orthopaedic device-related infections: A retrospective analysis

Comparison of diagnostic efficacy between 99mTc-methylene diphosphate SPECT/CT and MRI for bone and joint infections: a multicenter retrospective analysis

Objective

There is currently no non-invasive examination that can fully determine the diagnosis of osteomyelitis. SPECT/CT tomographic fusion imaging can provide both local metabolic activity and anatomical information to determine the condition and location. This study evaluates the diagnostic efficacy of 99mTc-MDP SPECT/CT in bone infections, compared to MRI.

Methods

In this multicenter retrospective study, 363 patients with suspected bone and joint infections or osteomyelitis were included. Participants underwent 99mTc-MDP SPECT/CT and/or MRI examinations, supplemented by pathogenic bacterial cultures and histopathological analysis.

Results

Only SPECT/CT was tested in 169 patients, and only MRI was used in 116. 78 people have implemented both inspections and have detailed information. The diagnostic sensitivity and specificity of SPECT/CT for infection were 96% and 92% respectively, with an accuracy of 96%. For MRI, these figures were 88%, 84%, and 87% respectively.

Conclusion

This represents the largest global study to date evaluating osteomyelitis and bone infection diagnosis using 99mTc-MDP SPECT/CT tomographic fusion imaging. The findings indicate that 99mTc-MDP SPECT/CT fusion imaging offers superior diagnostic accuracy compared to MRI. This is particularly evident in cases involving metallic implants and chronic infections. 99mTc-MDP SPECT/CT fusion imaging emerges as a highly suitable non-invasive diagnostic modality, facilitating enhanced clinical follow-up and treatment.

Magnetic Resonance Imaging of Total Ankle Arthroplasty: State-of-The-Art Assessment of Implant-Related Pain and Dysfunction

Total ankle arthroplasty (TAA) is an effective alternative for treating patients with end-stage ankle degeneration, improving mobility, and providing pain relief. Implant survivorship is constantly improving; however, complications occur. Many causes of pain and dysfunction after total ankle arthroplasty can be diagnosed accurately with clinical examination, laboratory, radiography, and computer tomography. However, when there are no or inconclusive imaging findings, magnetic resonance imaging (MRI) is highly accurate in identifying and characterizing bone resorption, osteolysis, infection, osseous stress reactions, nondisplaced fractures, polyethylene damage, nerve injuries and neuropathies, as well as tendon and ligament tears. Multiple vendors offer effective, clinically available MRI techniques for metal artifact reduction MRI of total ankle arthroplasty. This article reviews the MRI appearances of common TAA implant systems, clinically available techniques and protocols for metal artifact reduction MRI of TAA implants, and the MRI appearances of a broad spectrum of TAA-related complications.

An Atypical Presentation of Early Periprosthetic Infection After Cervical Disc Arthroplasty: A Case Report

CASE

A 22-year-old woman with Klippel-Feil syndrome who underwent cervical disc arthroplasty (CDA) presented 3 months postoperatively with worsening neck pain and radiculopathy. Work-up was negative for infection, but single-photon emission computed tomography revealed increased metabolic activity in the vertebral body below the implant. During revision, the implant was grossly loose and multiple cultures grew Cutibacterium acnes. She was treated with an antibiotic course and conversion to anterior fusion without recurrence.

CONCLUSION

This report highlights the rare presentation of an early periprosthetic infection after CDA caused by C. acnes.

Fluorodeoxyglucose PET/Computed Tomography in Evaluation of Prosthetic Joints and Diabetic Foot: A Comparative Perspective with Other Functional Imaging Modalities

Infection imaging has been an important part of nuclear medicine practice. Infections in prosthetic joints and diabetic foot are associated with devastating complications, posing substantial challenge for both diagnosis and overall management. For many years, conventional nuclear medicine techniques have been used to frame a painful joint arthroplasty or diabetic foot infection. The various functional nuclear imaging modalities used include labeled leukocyte imaging, combined leukocyte-marrow scintigraphy, antigranulocyte antibody scintigraphy, 3-phase bone scintigraphy, and fluorodeoxyglucose PET/computed tomography, yet no single method has proved to be highly sensitive and specific and at the same time safe, simple, and time-effective.

The Temporal Impact of Prosthesis Implantation and Semi-Quantitative Criteria on the Diagnostic Efficacy of Triple-Phase Bone Scanning for Periprosthetic Joint Infection

Objective

To evaluate the diagnostic efficacy of triple‐phase bone scanning and the temporal impact of prosthesis implantation on the diagnostic efficacy of triple‐phase bone scanning for periprosthetic joint infection (PJI).

Methods

Patients who were admitted to our hospital for joint pain and dysfunction after total joint arthroplasty between 2014 and 2020 were retrospectively included. Triple‐phase bone scanning was performed, and the blood pool images were evaluated to obtain the semi‐quantitative criteria. The patients were then grouped into six groups according to the time interval from index primary arthroplasty to triple‐phase bone scanning. We examined whether there were significant differences in sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy between the groups.

Results

Overall, 66 patients who underwent total hip arthroplasty (THA) and 74 patients who underwent total knee arthroplasty (TKA) were analyzed. No significant differences were observed between visual analysis and semi‐quantitative measurement in terms of sensitivity, specificity, PPV, NPV, and accuracy. For patients with a time interval from prosthesis implantation to bone scanning of >1 year, visual analysis had a higher PPV (100%) in patients who underwent THA and the use of semi‐quantitative criteria had a higher NPV (85.7%) in patients who underwent TKA.

Conclusion

The semi‐quantitative criteria showed no advantages in the diagnosis of PJI. In addition, triple‐phase bone scanning demonstrated good clinical diagnostic efficacy when the time interval from prosthesis implantation to bone scanning was >1 year.

The Role of 99mTc-antigranulocyte SPECT/CT In Community-Acquired Diabetic Foot Osteomyelitis: A Clinical Experience

BACKGROUND

Magnetic resonance imaging (MRI) is the actual gold standard for the radiological diagnosis of diabetic foot osteomyelitis (DFO).

MATERIALS AND METHODS

MRI is not always available and many patients have contraindications. We evaluated the clinical value of 99mTc-antigranulocyte SPECT/CT (AGS) in eight DFO patients who underwent MRI before.

RESULTS

The goal was to have a better clinical view on the extent of bone infection and to ameliorate the surgical approach for DFO. However, this additional scintigraphy did not change anything in the clinical approach.

CONCLUSION

We shared our experience with AGS for clinical management of complex DFO cases.

Hybrid imaging of complicating osteomyelitis in the peripheral skeleton

Diagnosing complicating osteomyelitis (COM) is clinically challenging. Laboratory tests are of limited utility, and other than isolation of the offending organism, diagnostic imaging tests are of paramount importance. Nuclear Medicine techniques play an important role in noninvasive evaluation of osteomyelitis, using both single-photon emission tomography (SPECT) and positron emission tomography (PET) radiopharmaceuticals. It is well-known that those conventional imaging modalities are not performing well in the distinction between soft-tissue and deep bone infection due to the lack of anatomical information. These difficulties have been overcome, to a great extent, with the introduction of in-line SPECT-CT and PET-CT systems which have revolutionized the field of diagnostic medical imaging. Hybrid imaging is especially useful in sites of suspected COM with underlying structural bone alterations. The first clinical studies with these integrated hybrid machines in the field of COM, including metallic implants imaging, are highly promising. In summary, WBC/AGA SPECT-CT and FDG-PET-CT seem to be the most accurate hybrid imaging modality for COM of the peripheral bone. However, there are still false positives, especially in aseptic tibial nonunions and/or metallic implants, as well as in the immediate postoperative setting. Furthermore, there is a lack of well-designed large multicentre prospective studies. Hopefully, in the future, the complementary use of morphological and functional hybrid imaging modalities may overcome some of the challenges faced in the assessment of COM.

The Role of Imaging Techniques to Define a Peri-Prosthetic Hip and Knee Joint Infection: Multidisciplinary Consensus Statements

Diagnosing a peri-prosthetic joint infection (PJI) remains challenging despite the availability of a variety of clinical signs, serum and synovial markers, imaging techniques, microbiological and histological findings. Moreover, the one and only true definition of PJI does not exist, which is reflected by the existence of at least six different definitions by independent societies. These definitions are composed of major and minor criteria for defining a PJI, but most of them do not include imaging techniques. This paper highlights the pros and cons of available imaging techniques—X-ray, ultrasound, computed tomography (CT), Magnetic Resonance Imaging (MRI), bone scintigraphy, white blood cell scintigraphy (WBC), anti-granulocyte scintigraphy, and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), discusses the added value of hybrid camera systems—single photon emission tomography/computed tomography (SPECT/CT), PET/CT and PET/MRI and reports consensus answers on important clinical questions that were discussed during the Third European Congress on Inflammation/Infection Imaging in Rome, December 2019.