1342

A preliminary study on the correlation between fat infiltration and muscle asymmetry in lumbar intervertebral disc herniation by using IDEAL-IQ
Hui Hao1, Jiayin Tong1, Xiaocheng Wei2, Jianxin Guo1, Xijun Jiao1, Xianghui Zhang1, and Jian Yang1

1Department of Radiology, the First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China, 2MR Research China, GE Healthcare, Bei Jing, China

Synopsis

Disc herniation is one of the most common conditions of the lumbar spine.More and more people are suffering from this symptoms.Our study focused on fat infiltration of bilateral lumbar multifidus muscle in patients with lumbar disc herniation. Based on the IDEAI-IQ technology, proton density fat fraction of lumbar multifidus muscle is evaluted. The preliminary results show that the degree of fat infiltration in the lumbar spine protrusion is relatively higher in the herniated side than contralateral side.Our results can reflect the degree of fat infiltration quantitatively, which can be further expanded into the quantitative classification of different populations and different causes.

Introduction

Lumbar disc herniation is a common disease, the complications are back pain, lower limb pain and other symptoms affecting people's normal work and life. A previous study performed histopathological analysis on multifidus muscle specimens and have shown the nerve root compression by lumbosacral disc herniation causes paraspinalmuscle changes1. By measuring signal intensity on T2 weighted images, Maryse Fortin et al. concluded that there was greater fat infiltration on the side of the herniated disc and around the spine2. Iterative decomposition of water and fat with echo asymmetry and least-squares estimation intelligent quantification (IDEAL-IQ) is a three-dimensional fast gradient echo sequence that uses multiple acquired echoes to generate proton density fat fraction (PDFF) maps, and is believed to be more suitable for assessment of fat penetration in bilateral lumbar multifidus muscle. In one latest report, Zhang Y et al. evaluated the reliability of this technique on healthy volunteers. By measureing the fat content of the lumbar vertebral marrow and paraspinal muscles, the authors concluded that this technique features high reliability and is suitable for use in clinical practice3. Therefore, in this study, we aim to investigate the correlation between fat infiltration and muscle asymmetry in lumbar intervertebral disc herniation by using IDEAL-IQ technique.

Methods

The Institutional Review Board approved this study and all the written informed consents were obtained from participants. In this study, 23 patients with lumbar intervertebral disc herniation were included. Four cases were excluded due to tumor bone metastasis, and another one due to compression fracture. All MR examinations were performed on a 3T MR scanner (Discovery MR750W , GE Healthcare, Milwaukee, Wisconsin) equipped with a TL Spine coil. The scan protocol included a Sag T2 Fast Recovery Fast Spin Echo (FRFSE)，a Sag T1 FSE，a Ax T2 FRFSE and a Ax IDEAL IQ. Detailed parameters for above sequence can be found in Table1. The anatomical images from first three sequences help to clarify the vertebral body and direction of disc herniation. Region of interest (ROI) was manually depicted on PDFF map from IDEAL-IQ to cover the area of the multifidus muscle, including both affected and non-affected side (Figure1). All statistical analysis were performed by using SPSS 20.0 (SPSS, Chicago, IL, USA); p<0.05 was considered as statistically significant difference.

Results

Of the 23 level of the herniation ,include multiple levels who are multiple disc herniations. There was no significant difference in gender and age.The data follows a normal distribution. Kolmogorov-Smirnova show the affected sides (P=0.200)and unaffected sides (P=0.200).Paired T tests were used to compare the FF value between the affected and unaffected sides at the level of the herniation.Significant differences presented in affected and unaffected sides(Table 2).

Discussion

In this study, quantitative assessment of the herniated side of the lumbar intervertebral disc with the degree of muscle fat infiltration in that side were performed. The IDEAL-IQ imaging technique permits a rapid and accurate assessment of the fat content of tissue in a single sequence. This approach permits confirmation of the fat-to-water ratio and correction of T2* effects without the necessity for extra sequences to address mapping and potential misregistration of the image4. Correlation between fat infiltration and muscle asymmetry was found .In our study, which is consistent with previously published results. However, due to the small sample size, lacking of analysis on age, gender, sports status and duration of illness, subsequent deep studies are certainly needed.

Conclusion

Patients with prolapse of lumbar intervertebral disc have higher degree of fat infiltration on the protruding side of the paravertebral muscle. The IDEAL-IQ technique seems to be a fast and easy approach for fat quantitative evaluation of paravertebral muscle.

Acknowledgements

No acknowledgement found.

References

1.Franke J, Hesse T, Tournier C, Schuberth W, Mawrin C, LeHuec JC, et al. Morphological changes of the multifidus muscle in patients with symptomatic lumbar disc herniation. J Neurosurg Spine. 2009;11:710–4.

2.Fortin M, Lazáry À, Varga P P, et al. Paraspinal muscle asymmetry and fat infiltration in patients with symptomatic disc herniation[J]. European Spine Journal, 2016, 25(5):1452-1459.

3.Zhang Y, Zhou Z, Wang C, Cheng X, Wang L, Duanmu Y, Zhang C, Veronese N,Guglielmi G. Reliability of measuring the fat content of the lumbar vertebral marrow and paraspinal muscles using MRI mDIXON-Quant sequence. Diagn Interv Radiol. 2018 Sep;24(5):302-307.

4.O’Regan DP, Callaghan MF, Wylezinskaarridge M, et al. Liver fat content and T2*: simultaneous measurement by using breath-hold multiecho MR imaging at 3.0 T-feasibility. Radiology 2008;247:550–557.

Figures

Figure1 .a.Sag T2 FRFSE(arrow shows the disc herniated),b.Sag T1 FSE(arrow shows the disc herniated)c.Ax T2 FRFSE(arrow shows the disc herniated with left side)d.IDEAL-IQ FaFra phase ,the value of ROI is1:34.27,2:32.69


Table 1. Detailed parameters of scan sequences including TR, TE, slice thickness (Thickness), spacing between slices (space), matrix size and number of average (NEX).

Table2. statistical results

Proc. Intl. Soc. Mag. Reson. Med. 27 (2019)
1342