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Quantitative multiparametric UTE-MRI sequences for early cartilage degeneration corresponding to biochemical components——an in vivo study
Xiaolian Su1, Lidi Wan1, Yitong Wang1, Jieying Chen1, Qingqing Wen2, Pu-Yeh Wu2, and Guangyu Tang1
1Radiology, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai, China, 2MR Research，GE Healthcare, Beijing, China

Synopsis

Keywords: Cartilage, Cartilage

Motivation: The detection of early cartilage degeneration by UTE-MRI has been demonstrated in many in vitro experiments but lacks validation in in vivo studies.

Goal(s): To explore the feasibility of UTE-MRI quantitative imaging in the diagnosis of early cartilage degeneration in vivo, compare the diagnostic efficacy of various sequences and explore their corresponding pathological and biochemical basis.

Approach: Volunteers were recruited preoperatively to perform MRI for comparison with postoperative pathology.

Results: UTE-MRI values have shown greater in vivo diagnostic value for early cartilage degeneration compared to conventional T2 and T1ρ values, and mainly reflect different aspects of cartilage degeneration.

Impact: Validating the clinical utility of UTE-MRI in vivo for diagnosing early cartilage degeneration contributes to the early detection and intervention of articular cartilage degeneration in osteoarthritis patients.

Introduction

In clinical studies, non-invasive conventional MRI protocols such as T1ρ, T2 mapping, and T2* mapping are often utilized to detect early cartilage degeneration (1). However, they may not capture signals from all layers of cartilage, especially the calcified and deep layers, due to their relatively long echo times. Ultra-short echo time (UTE) sequences have been developed and increasingly employed to overcome the aforementioned shortcomings, with echo times as short as 8 μs (2). And there are few reports on using UTE-MRI quantitative imaging to detect early cartilage degeneration in vivo, especially the research on the pathophysiological and biochemical basis of imaging is rare. Therefore, it is necessary to compare the advantages and disadvantages of various UTE-MRI quantitative imaging techniques in the early diagnosis of cartilage degeneration in vivo and explore its pathological and biochemical basis.

Methods

Twenty volunteers with osteoarthritis (OA) for total knee arthroplasty (TKA) at Shanghai Tenth People's Hospital were prospectively recruited between June 2020 and August 2021. UTE-MRI sequences (UTE-MT, UTE-AdiabT1ρ and UTE-T2* mapping) and conventional sequences (CubeQuant-T2 and CubeQuant-T1ρ) were performed one day before the operation of the affected knee cartilage. Seven regions of interests (ROIs) were manually drawn on the mid-sagittal section of the tibial plateau and four ROIs on lateral femoral condyle images for each patient to calculate the UTE-MRI quantitative values. During TKA, cartilage samples (including the replaced lateral femoral condyle and tibial plateau) were collected in strict accordance with the preset positions corresponding to MRI images. Then, the pathological and biochemical components of the corresponding ROI were obtained, including histological grading (Mankin scores), glycosaminoglycan (GAG) content (constituting PG), collagen structural integrity and water content of the cartilage. The integrity of collagen structure was assessed using the PLM-CO scores, which range from total disorganization (score 0) to healthy zonal architecture (score 5) (3). The receiver operating characteristic (ROC) was conducted to evaluate the performance of three UTE-MRI quantitative imaging techniques.

Results

91 ROIs from volunteers of 7 males (age range: 68 to 78 years; 74±3 years) and 13 females (age range: 57 to 79 years; 67±6 years) were evaluated, and divided into four groups according to Mankin score: normal cartilage (grade 1 for scores 0-1, n=17); mild degeneration (grade 2 for scores 2-5, n=38); moderate degeneration (grade 3 for scores 6-9, n=28); and severe degeneration (grade 4 for scores 10-14, n=8) (Fig. 1). UTE-based magnetization transfer ratio (UTE-MTR) (r=-0.619, P <.001), UTE-AdiabT1ρ (r=0.568, P <.001), and UTE-T2* values (r=-0.495, P <.001) showed higher correlation with Mankin scores than T2 values (r=0.287, P=.006) and T1ρ values (r=0.435, P<.001) (Fig. 2). Of them, UTE-MTR had the highest diagnostic performance on early cartilage degeneration (AUC=0.824, P<.001) (Fig. 3). UTE-MTR values performed moderate correlation with PLM-CO (r=0.536, P<.001), UTE-AdiabT1ρ value performed moderate correlation with GAG content (r=-0.652, P<.001), while UTE-T2* value performed moderate correlation with W/D ratio (r=-0.518, P<.001).

Discussion

It is found that three quantitative UTE-MRI sequences all showed the higher correlation with Mankin scores than T2 and T1ρ value. And UTE-MTR and UTE-AdiabT1ρ values were able to distinguish normal cartilage from mildly degenerated cartilage, while UTE-T2* and T2 and T1ρ values lacked the ability. UTE-MRI enables the full-layer evaluation of cartilage that cannot be displayed by conventional MRI sequences (4). Additionally, the magic angle effect still had an impact on UTE-T2* and UTE-T1ρ quantitative analysis (5, 6). The value influenced by the magic angle may obscure the effect of cartilage degeneration, thereby impacting the accuracy of the results. However, it has been confirmed that UTE-MT and UTE-AdiabT1ρ exhibited reduced sensitivity to the magic angle effect and will help to improve the robustness of quantitative UTE-MRI sequences (7, 8). UTE-MTR and UTE-AdiabT1ρ values respectively performed moderate correlation with PLM-CO and GAG content. The biochemical alterations of early cartilage degeneration existed in the extracellular matrix (ECM), including the loss of normal collagen network structure and reduction of PG, instead of cartilage fibrillation and fragmentation which happened in the advanced OA (9).UTE-T2* values performed moderate correlation with W/D ratio and this may be why UTE-T2* values failed to distinguish normal and mild cartilage degeneration, but performs well in mild to moderate and mild to severe cartilage degeneration.

Conclusion

Quantitative UTE-MRI values have shown greater in vivo diagnostic value for early cartilage degeneration compared to conventional T2 and T1ρ values. Of them, UTE-MTR has the highest efficiency in diagnosing early cartilage degeneration. UTE-MTR、UTE-AdiabT1ρ and UTE-T2* values can mainly reflect different aspects of cartilage degeneration, namely integrity of collagen structure, PG content and water content, respectively.

Acknowledgements

No acknowledgement found.

References

1. Palmer AJ, Brown CP, McNally EG, et al. Non-invasive imaging of cartilage in early osteoarthritis. The bone & joint journal. 2013;95-b(6):738-46. doi:10.1302/0301-620x.95b6.31414

2. Siriwanarangsun P, Statum S, Biswas R, Bae WC, Chung CB. Ultrashort time to echo magnetic resonance techniques for the musculoskeletal system. Quant Imaging Med Surg. 2016;6(6):731-43. doi:10.21037/qims.2016.12.06

3. Changoor A, Tran-Khanh N, Méthot S, et al. A polarized light microscopy method for accurate and reliable grading of collagen organization in cartilage repair. Osteoarthritis Cartilage. 2011;19(1):126-35. doi:10.1016/j.joca.2010.10.010

4. Afsahi AM, Sedaghat S, Moazamian D, et al. Articular Cartilage Assessment Using Ultrashort Echo Time MRI: A Review. Front Endocrinol (Lausanne). 2022;13:892961. doi:10.3389/fendo.2022.892961

5. Du J, Chiang AJ, Chung CB, et al. Orientational analysis of the Achilles tendon and enthesis using an ultrashort echo time spectroscopic imaging sequence. Magn Reson Imaging. 2010;28(2):178-84. doi:10.1016/j.mri.2009.06.002

6. Du J, Statum S, Znamirowski R, Bydder GM, Chung CB. Ultrashort TE T1ρ magic angle imaging. Magn Reson Med. 2013;69(3):682-7. doi:10.1002/mrm.24296

7. Wu M, Ma YJ, Kasibhatla A, et al. Convincing evidence for magic angle less-sensitive quantitative T(1ρ) imaging of articular cartilage using the 3D ultrashort echo time cones adiabatic T(1ρ) (3D UTE cones-AdiabT(1ρ) ) sequence. Magn Reson Med. 2020;84(5):2551-60. doi:10.1002/mrm.28317

8. Ma YJ, Shao H, Du J, Chang EY. Ultrashort echo time magnetization transfer (UTE-MT) imaging and modeling: magic angle independent biomarkers of tissue properties. NMR Biomed. 2016;29(11):1546-52. doi:10.1002/nbm.3609

9. Qian Y, Williams AA, Chu CR, Boada FE. Multicomponent T2* mapping of knee cartilage: technical feasibility ex vivo. Magn Reson Med. 2010;64(5):1426-31. doi:10.1002/mrm.22450

Figures

Figure 1. Box-plot diagrams illustrating UTE-MRI values including UTE-MTR (a), UTE-AdiabT1ρ (b) and UTE-T2* (c) between different Mankin grades. UTE-MTR, ultrashort echo time-based magnetization transfer ratio; UTE-AdiabT1ρ, ultrashort echo time-based adiabatic T1ρ; UTE-T2*, ultrashort echo time-based T2*. ns, nonsignificant; **,0.001≤P<0.05; ***, P<0.001.

Figure 2. The correlation among quantitative MRI examination and Mankin scores. UTE-MTR (r=-0.619, P<.001) and UTE-AdiabT1ρ (r=0.568, P<.001) values showed moderate correlation with Mankin scores. The UTE-T2* showed low correlation with Mankin scores (r=-0.495, P<.001). T1ρ and T2 values showed low and negligible correlation with Mankin scores, respectively. UTE-MTR, ultrashort echo time-based magnetization transfer ratio; UTE-AdiabT1ρ, ultrashort echo time-based adiabatic T1ρ; UTE-T2*, ultrashort echo time-based T2*.

Figure 3. ROC curves of quantitative UTE-MRI sequences for the diagnosis of mild cartilage degeneration. The AUC of UTE-MTR (AUC =0.824, 95% CI: 0.706 to 0.943; P<.001) and UTE-AdiabT1ρ (AUC =0.796, 95% CI: 0.675 to 0.917, P=.001) were higher than that of UTE-T2* (AUC =0.635, 95% CI: 0.461 to 0.808; P=.113). AUC, area under the curve; CI, confidence interval; ROC, receiver-operating characteristic; UTE-MTR, ultrashort echo time-based magnetization transfer ratio; UTE-AdiabT1ρ, ultrashort echo time-based adiabatic T1ρ; UTE-T2*, ultrashort echo time-based T2*.

Proc. Intl. Soc. Mag. Reson. Med. 32 (2024)
4812
DOI: https://doi.org/10.58530/2024/4812