Combined T2 Mapping and Diffusion Tensor Imaging: A Sensitive Tool to Assess Myofascial Trigger Points in a Rat Model

Abstract

Background Myofascial trigger points (MTrPs) are defined as very small and hypersensitive points in skeletal muscle that are palpable, and produce localized pain on compression. The aim of this study was to explore the feasibility of combining T2 mapping with diffusion tensor imaging (DTI) for assessing MTrPs in a rat model and to investigate properties of the pathophysiological mechanisms. Methods Twenty-four Sprague-Dawley rats (model group, n = 14; control group, n = 10) underwent a magnetic resonance imaging (MRI) examination on a 3 T-MRI-scanner with a protocol consisting of T2 mapping and DTI. The MTrPs were established by blunt strike in combination with eccentric exercise. Enzyme-linked immunosorbent assays (ELISAs) were used to detect the levels of interleukin-1ß (IL-1ß) and interleukin-2 (IL-2) and their results were correlated with T2 values. Parameters from MRI including T2 values, fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) were compared between the two groups. Histological analysis was applied to provide an additional supply for MRI findings. Results The MTrPs of rats displayed significantly increased T2 values and FA (= 0.000) compared with normal controls, whereas MD and RD values were significantly lower ( P = 0.031, = 0.000, respectively). There was no statistically significant difference in AD between the two groups ( P = 0.400). These differences were accompanied by elevated levels of IL-1ß and interleukin-2 IL-2 in the MTrP group compared with controls. T2 values were positively correlated with elevated IL-1ß levels ( r = 0.543, P < 0.05) but were not correlated with IL-2 levels ( P > 0.05). Conclusion Combining T2 and DTI sequences creates a sensitive tool to assess MTrPs in a rat model. These data clarify a hypothesis that a trigger point is a chronic and mild muscle injury with inflammation.

Engeletin alleviates depressive‐like behaviours by modulating microglial polarization via the LCN2/CXCL10 signalling pathway

“…Multiparameter MRI scans are currently regarded as the most effective approach to noninvasively analysing the pathological basis of MDD in vivo 29 . T1WI and T2WI strategies enable the visualization of brain anatomy, whereas quantitative indices such as DTI measurements and T2 values can provide quantitative sensitivity when attempting to detect injury to the nervous system and gauge the efficacy of neuroprotective interventions 30 . The T2 hyperintensity of the bilateral prefrontal cortex is associated with increases in inflammation, vascular permeabilization, myelin turnover, water content and the accumulation of by‐products of myelin and axonal breakdown 31,32 .…”

“… 29 T1WI and T2WI strategies enable the visualization of brain anatomy, whereas quantitative indices such as DTI measurements and T2 values can provide quantitative sensitivity when attempting to detect injury to the nervous system and gauge the efficacy of neuroprotective interventions. 30 The T2 hyperintensity of the bilateral prefrontal cortex is associated with increases in inflammation, vascular permeabilization, myelin turnover, water content and the accumulation of by‐products of myelin and axonal breakdown. 31 , 32 ADC and FA values are key quantitative DTI parameters that are closely correlated with the pathogenesis of depression.…”

Engeletin alleviates depressive-like behaviors by modulating microglial polarization via the LCN2/CXCL10 signaling pathway

“…Multiparameter MRI scans are currently regarded as the most effective approach to noninvasively analyzing the pathological basis of MDD in vivo [26]. T1WI and T2WI strategies enable the visualization of brain anatomy, whereas quantitative indices such as DTI measurements and T2 values can provide quantitative sensitivity when attempting to detect injury to the nervous system and gauge the e cacy of neuroprotective interventions [27]. The T2 hyperintensity of the bilateral prefrontal cortex is associated with increases in in ammation, vascular permeabilization, myelin turnover, water content, and the accumulation of byproducts of myelin and axonal breakdown [28,29].…”

Assessment of the effects of transforming growth factor beta1 (TGF-β1)-Smad2/3 on fibrosis in rat myofascial trigger points using point shear wave elastography

“…Therefore, there is a high demand for imaging techniques that provide quantitative and objective measurements for tense belts and MTrPs. Magnetic resonance imaging (MRI) and ultrasound (US) have been used to identify MTrPs for diagnosis and treatment evaluation ( Jiang et al, 2020 ; Liang, Guo & Li, 2021 ; Sikdar et al, 2009 ; Yu et al, 2021 ). Although both are noninvasive examination techniques, US has faster data acquisition and a lower cost than MRI.…”