Changes in calf muscle elasticity in hypogonadal males before and after testosterone substitution as monitored by magnetic resonance elastography

Abstract

Purpose: We sought to determine whether differences in muscle elasticity between healthy age-related controls and patients with hypogonadism could be measured by a new, non-invasive method termed magnetic resonance elastography (MRE). Materials and methods: Twelve hypogonadal (21-68 years) and twenty-seven healthy age-related men (20-76 years) were examined. In the hypogonadism group, serum testosterone levels were compared and MRE was conducted prior to and after 6 months of therapy in 6 of the 12 patients. MRE was performed by mechanically exciting the soleus muscle that was used because of its uniformly distributed muscle fibers, size, and accessibility, with a custom designed piezoelectric-actuator using a modified phase-contrast sequence. For mechanical excitation the actuator lever was placed on the anterior surface of the calf. The subjects had to maintain a force of 0-20% of their maximum voluntary contraction against a home-built footplate that was mounted on the MR table. All images were phase unwrapped and reconstructed into shear modulus elastograms using the local frequency estimation technique. Results: Testosterone levels were significantly higher after 6 months of treatment. A statistical difference in the shear modulus was observed prior to and after 6 months of testosterone therapy and was nearly the same as in the healthy age-related control group. Conclusion: MRE seems to be a promising technique for the evaluation of therapeutic effects in patients with hypogonadism and possibly in other diseases with muscular effects.European Journal of Endocrinology 156 673-678

Endosonographic elastography of the anal sphincter in patients with fecal incontinence

“…myositis and myopathy in peripheral muscle structures of patients with hyperthyroidism [20,39,40,43]. In addition, the actual state of muscular contraction during the examination was found to influence shear modulus and viscosity, yielding different elastogram color distributions in both sonographic and MRI settings [20][21][22][23][35][36][37][38][39]. It is therefore possible that the observed IAS and EAS elastogram differences may be due at least partially to different individual muscular contraction states during RTE examination, leading to different color distributions.…”

“…We also compared a visual assessment scale with a computerized program for further quantifying elastic properties in terms of elastogram color distribution within the sphincter muscle. Although strain effects on peripheral striated muscles have recently been measured elastographically [20][21][22][23], no such data are available for the anal sphincter. In addition, we studied whether there are associations between elastographically quantified properties of the IAS and EAS and clinical and functional characteristics.…”

Three‐parameter shear wave inversion in MR elastography of incompressible transverse isotropic media: Application to in vivo lower leg muscles

“…Unlike common imaging markers of MRI or sonography, elastography-measured shear modulus values vary largely upon muscle function (5)(6)(7)(8)(9)(10). Many clinical elastography studies have demonstrated the sensitivity of shear elastic parameters to skeletal muscle disorders and dysfunctions (11)(12)(13)(14)(15)(16)(17).…”

Characterization of muscle architecture in children and adults using magnetic resonance elastography and ultrasound techniques

“…Additional architectural characteristics of muscle were obtained with magnetic resonance elastography (MRE) technique. Indeed, this method generates shear waves inside the muscle tissue in order to measure the mechanical properties (Dresner et al, 2001;Basford et al, 2002;Bensamoun et al, 2006Bensamoun et al, , 2007Brauck et al, 2007;Chen et al, 2007Chen et al, , 2008Domire et al, 2009) and several studies have observed the propagation of the shear waves along the muscle fiber (Bensamoun et al, 2006;Sack et al, 2002). Thus, V-waves, oblique waves and longitudinal waves were observed inside the biceps brachii, the vastus medialis and the sartorius muscles, respectively, reflecting their own muscles architecture.…”