Assessment of elastic parameters of human skin using dynamic elastography

Abstract

Sonoelastography and transient elastography are two ultrasound-based techniques that facilitate noninvasive characterization of the viscoelastic properties of soft tissues by investigating their response to shear mechanical excitation. Young's modulus is the principle assessment parameter. Because it defines local tissue stiffness, it is of major interest for the medical imaging and cosmetic industries as it could replace subjective palpation by yielding local, quantitative information. In this paper, we describe a new high-resolution device capable of measuring local Young's modulus in very thin layers (1-5 mm) and devoted to the in vivo evaluation of the elastic properties of human skin. It uses an ultrasonic probe (50 MHz) for tracking the displacements induced by a 300 Hz shear wave generated by a ring surrounding the transducer. The displacements are measured using a conventional cross-correlation technique between successive ultrasonic back-scattered echoes. First, this noninvasive technique has been experimentally proven to be accurate for investigating elasticity in different skinmimicking phantoms. Second, data were acquired in vivo on human forearms. As expected, Young's modulus was found to be higher in the dermis than in the hypodermis and other soft tissues.

Ultrasound Elastography Assessment of Skin Involvement in Systemic Sclerosis: Lights and Shadows

“…Recently, UE has been used in the diagnosis of breast, thyroid, and prostate cancer, lymph node metastasis, liver fibrosis 4,5,6,10 , musculoskeletal disorders 11 , and skin diseases. UE has been used in particular in differentiation between benign and malignant lesions 12 .…”

Medical ultrasound: imaging of soft tissue strain and elasticity

“…An instrument with a 50 MHz focused transducer surrounded by a small annulus vibrating at 300 Hz which generated shear waves in the skin with which it was in contact has been described [200]. This allowed the local elasticity to be estimated from the shear wave velocity, which was recovered from phase analysis of the ultrasound backscattered by the displacement field.…”

Soft Tissue Finite Element Modeling and Calibration of the Material Properties in the Context of Computer-Assisted Medical Interventions

“…Other excitation methods include indentation (Ottensmeyer, 2001;Carter et al, 2001;Samur et al, 2007) using a handheld or robotic indenter, and torsion (Agache et al, 1980) or ballistometer (Jemec et al, 2001) which consists of striking the tissue with a known mass and a known force. Ultrasound measurement (Chen et al, 1996;Gennisson et al, 2004) is another method linked with the emerging field of elastography.…”