4209

Monitoring changes of knee with Amateur Marathon athletes using Synthetic Magnetic Resonance Imaging ：A preliminary study
Yijie Fang1, Wenjun Yu1, Long Qian2, and Shaolin Li1
1The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China, 2MR Research, GE Healthcare, Beijing, China

Synopsis

To explore the value of Synthetic magnetic resonance imaging (Sy MRI) in the quantitative monitoring of knee joint structural changes and cartilage of amateur marathon runners before and after the whole marathon. Twenty-six knee joints of healthy volunteers who took part in the marathon were scanned by Sy MRI technology one week before the race and within 48 hours after the race. The values of T1, T2 and PD of knee cartilage in whole and different regions before competition were higher than those of 48 hours after the marathon, and the difference was statistically significant

Introduction

Marathon is very common, and it brings various sports injuries, especially knee joint injuries1-3.Previous literature has shown that Synthetic magnetic resonance imaging (Sy MRI) can obtain quantitative images of morphology and function in one scan, and has good consistency with conventional MRI in knee joint4,5.This reasearch was to explore the value of Sy MRI in the quantitative monitoring of knee joint structural changes and cartilage of amateur marathon runners before and after the whole marathon.

Methods

Twenty-six knee joints of healthy volunteers who took part in the marathon were scanned by Sy MRI technology one week before the race and within 48 hours after the race. The conventional contrast weighted images Sy MRI-T1WI, Sy MRI-T2WI, Sy MRI-IW, Sy MRI-STIR and T1, T2, PD maps were obtained. 3D-CUBE-PD sequence was used as a reference to evaluate the detection of knee joint lesions6. The dynamic monitoring of knee articular cartilage before and after the whole marathon was carried out by Sy MRI quantitative maps, and the value of monitoring the dynamic changes of extracellular matrix of cartilage was evaluated. The knee joint articular surface was divided into CMFC, PMFC, CLFC, PLFC, MTP, LTP, Patella and Trochlear. The consistency between groups was tested by intra-group correlation coefficient (ICC). Paired t-test was used to compare the values of T1, T2 and PD of cartilage before and after competition.

Results

The two radiologists had good consistency in the measurement of T1, T2 and PD values of Sy MRI (ICC > 0.91). Except for the increase of knee joint effusion, there was no significant change in knee joint structure before and after exercise. The detection rate of Sy MRI sequence for cartilage injury and joint effusion was 100%, and the detection rate of meniscus lesions was 77.8%. The values of T1, T2 and PD of knee cartilage in whole and different regions before competition were higher than those of 48 hours after the marathon, and the difference was statistically significant (P < 0.001).

Discussion

In this study, it was found that the conventional contrast weighted images and quantitative pseudo-color maps obtained by SyMRI had a higher detection rate of knee joint lesions.
This study found that SyMRI can reflect the dynamic changes of global and local knee cartilage before and after the whole marathon, and the T1, T2 and PD values of knee cartilage after exercise are lower than those before exercise, and there is statistical significance.

Conclusion

Synthetic MRI technique has a good display of knee joint structural lesions, and is of high value in monitoring the dynamic changes of knee cartilage extracellular matrix in amateur marathon athletes.

Acknowledgements

NO

References

[1] Fredericson M, Misra AK. Epidemiology and aetiology of marathon running injuries[J]. Sports Med, 2007, 37(4⁃5):437⁃439.

[2] Alentorn⁃Geli E, Samuelsson K, Musahl V, et al. The association of recreational and competitive running with hip and knee osteoarthritis: a systematic review and meta⁃analysis [J]. J Orthop Sports Phys Ther, 2017, 47(6): 373⁃390.

[3] Fredericson M, Misra A K. Epidemiology and Aetiology of Marathon Running Injuries[J]. Sports Medicine, 2007, 37(4-5):437-439.

[4] Kumar N M, Benjamin F, Stern S E, et al. Synthetic MRI of the Knee: Phantom Validation and Comparison with Conventional MRI[J]. Radiology, 2018:173007-.

[5] Marion Roux, Tom Hilbert, Mahmoud Hussami, etal. MRI T2 Mapping of the Knee Providing Synthetic Morphologic Images: Comparison to Conventional Turbo Spin-Echo MRI[J]. Radiology. 2019;293(3):620-630.

[6] Richard Kijowski, Kirkland W. Davis, Michael A. Woods, M. Knee joint: comprehensive assessment with 3D isotropic resolution fast spin-echo MR imaging--diagnostic performance compared with that of conventional MR imaging at 3.0 T[J]. Radiology, 2009, 252(2):486.

Figures

Male, 35 years old, participated in the full marathon twice, and his medial half month later his foot was torn horizontally. Fig. ① - ⑧ showed 3d Cube-Pd and Magic (T1WI, IW, T2WI, stir, t1mapping, pdmapping, T2mapping) respectively. ① 3D cube-pd showed linear hyperintensity in the posterior horn of the medial meniscus, magiciw, T2WI and stir sequences showed mild hyperintensity in the posterior horn of the meniscus. figure ⑦ Pd-mapping. The signal intensity of medial meniscus was slightly increased in T1 mapping and figure ⑧ in T2WI mapping.

Male, 45 year old, participated in the whole marathon for 5 times, suffered from patellar cartilage injury. Fig. ① 3D cube-pd shows the absence of the inferior part of patellar cartilage, bone marrow edema under the articular surface, magec T1WI sequence, IW and T2WI show the absence of cartilage, and the bone marrow edema under the articular surface is not clear. Figure ⑦ PD mapping showed partial cartilage defect and slight increase of bone marrow edema signal. T2WI mapping showed that the signal intensity in some areas increased, but no obvious signal increase in bone marrow edema

Proc. Intl. Soc. Mag. Reson. Med. 29 (2021)
4209