Synopsis

Keywords: Musculoskeletal: Knee, Musculoskeletal: Joints, Musculoskeletal: Cartilage

The RSNA Quantitative Imaging Biomarker Alliance (QIBA) mechanism serves to establish and standardize imaging biomarkers. To date there is only one musculoskeletal QIBA committee that works on standardizing the application of T1ρ and T2 imaging as biomarkers for the quantification of cartilage composition. The committee has established claims for these biomarkers and composed a profile which includes requirements and recommendations for MRI acquisition, image analysis, participant handling, image quality assurance, and image interpretation. Currently the QIBA MSK biomarker committee is in the process of testing the profile to document clinical feasibility and assessing performance at different imaging institutions.

Purpose: To outline the RSNA Quantitative Imaging Biomarker Alliance (QIBA) mechanism to approve biomarkers and to report the efforts of the musculoskeletal QIBA committee to standardize the application of T1ρ and T2 imaging as biomarkers for the quantification of cartilage composition.
Summary: Cartilage loss is irreversible and up to now no effective pharmacotherapies are available to protect or regenerate cartilage. Quantitative or compositional MR imaging techniques have been developed to characterize the cartilage matrix quality at a stage where degenerative disease is at an early and potentially reversible stage, allowing prevention and life style interventions to halt disease progression (1). Studies have shown that cartilage quantitative imaging biomarkers allow earlier diagnosis, better prediction and more sensitive monitoring of early osteoarthritis of the knee (2, 3). The key advantage of these biomarkers is earlier detection before cartilage loss has happened and providing a truly quantitative, reproducible measurement. To date T1ρ and T2 relaxation time measurements are the most frequently used cartilage compositional imaging biomarkers with the best available reproducibility data.
To better standardize quantitative imaging biomarkers, the Radiological Society of North America launched the Quantitative Imaging Biomarkers Alliance (QIBA) in 2007. QIBA aims to "improve the value and practicality of quantitative imaging biomarkers by reducing variability across devices, sites, patients, and time" (4) and to "unite researchers, healthcare professionals and industry to advance quantitative imaging and the use of imaging biomarkers in clinical trials and clinical practice" (https://www.rsna.org/en/research/quantitative-imaging-biomarkers-alliance).
The QIBA Musculoskeletal (MSK) Committee aims to standardize the application of T1ρ and T2 imaging as biomarkers for the quantification of cartilage composition. To implement this task, the QIBA MSK Committee has worked on requirements and recommendations for acquisition devices, technologists, radiologists, reconstruction software, and image analysis tools involved in study participant handling, image acquisition, image data reconstruction, image quality assurance, and image interpretation. The requirements are focused on achieving sufficient reproducibility for the longitudinal evaluation of cartilage composition by using different MRI scanners.
In this presentation we will discuss the work of the musculoskeletal QIBA committee to standardize the application of T1ρ and T2 imaging as biomarkers for the quantification of cartilage composition. It should be noted that an outline of the QIBA profile has also been published in Radiology in 2021 (5).
The QIBA process has several steps and stages to establish an imaging biomarker which will be outlined:
(i) Claim: First a claim needs to be developed which can be either cross-sectional or longitudinal. A cross-sectional claim describes the imaging procedure’s ability to measure the imaging biomarker at one time point, while a longitudinal claim describes the ability to measure the change in the imaging biomarker over multiple time points. For cartilage compositional imaging the biomarker committee has chosen a longitudinal claim focusing on reproducibility including test-retest variability and minimum detectable change.
(ii) Profile Development: Using the QIBA template the committee develops a profile which centers around the claim and describes the requirements necessary to achieve the claim. The profile also includes assessment procedures and conformance. The MSK profile provides information on image data acquisition, analysis, and interpretation and assessment procedures for T1ρ and T2 cartilage imaging and test-retest conformance.
(iii) Public Comment and Consensus: As a next step the profile is distributed to experts in the field for review and comments. These comments are reviewed by the committee and addressed in the profile, thus obtaining a consensus document. The final version of the profile is reviewed and approved by the parent MRI Biomarker Committee and the Coordinating Committee. Once approved the profile is published.
(iv) Clinical feasibility and confirmation: The final steps include testing the profile to document clinical feasibility at different sites and assessing performance at the different sites. The QIBA cartilage compositional imaging profile is currently in these final stages.

Acknowledgements

I would like to acknowledge support through RSNA/QIBA and my QIBA Co-Chair Dr. Xiaojuan Li as well as NIH/NIAMS funding (R01AR077452, R01AR064771, R01AR078917, OAI).