Shear-Wave Elastography and Viscosity PLUS for the Assessment of Peripheric Muscles in Healthy Subjects: A Pre- and Post-Contraction Study.

Viscosity is a novel parameter, recently introduced in the use of elastographic techniques, correlating to shear-wave dispersion. The purpose of this study was to provide normal reference viscosity values for the peripheral muscles in healthy volunteers. This prospective study included 38 subjects who underwent US examinations between November 2021 and January 2022. Measurements were taken on the calf and the deltoid muscles in both pre- and post-contraction states. The age range was 21-29 years, with a median of 26 years. The SWE and ViPLUS values in the deltoid muscles were significantly higher than in the soleus muscles in both pre- and post-contraction sets (p = 0.002). There were statistically significant differences between the pre- and post-contraction values for both the SWE and ViPLUS values in the subgroup analysis. The ICC estimates and the 95% confidence intervals were based on a mean rating (k = 2), an absolute agreement, and a two-way random-effects model, demonstrating excellent agreement between the measurements taken by the two examiners.

Role of dynamic contrast enhanced magnetic resonance imaging in the diagnosis and management of vascular lesions of the head and neck.

Vascular anomalies comprise a wide and heterogeneous group of lesions that may be found in all parts of the body, with most of the cases of vascular malformations involving the head and neck region. Ultrasound (US) is the reliable first-line imaging technique to assess flow parameters. However, in some cases, US fails to depict the real extent of the lesions. On the other hand, magnetic resonance imaging (MRI) allows the evaluation of the full extension and anatomic relationship of the vascular anomalies with the neighboring structures and provides hemodynamic characterization using dynamic contrast enhanced MRI (DCE-MRI), avoiding unnecessary invasive catheter-based procedures. DCE-MRI angiography can make a distinction between low and high flow vascular anomalies and it is useful for selecting adequate therapy and appreciating prognosis. The aim of this paper is to review the role of DCE -MRI in the evaluation of flow characteristics and lesion extent in vascular anomalies of the head and neck region.