Assessment of Cutaneous Sclerotic Diseases

 

Cutaneous sclerotic disorders are histologically characterized by increased fibrosis and collagen hyalinization in the dermis and deeper soft tissue. These conditions can be a significant source of morbidity, but there is no reliable measure to quantify disease severity in both the clinical and research setting [1]. Acoustic Radiation Force Impulse (ARFI) and Shear Wave Elasticity Imaging (SWEI) use ultrasound waves to make micron level transient deformation in soft tissue and measure the its dynamics to directly quantify material properties such as elasticity and viscosity [2]. They are sensitive to the functional pathology of sclerosis, making them ideal for assessing fibrotic conditions [3]. Already proven useful in evaluating fibrosis of the liver [4], this technology can be translated for use in cutaneous sclerosis to answer the clinical gaps in this field.

This study aims to determine the potential for employing ARFI/SWEI in the clinical evaluation of cutaneous sclerosis, testing the hypothesis that the diseased skin is stiffer than the normal skin.

Current work in SWEI in the skin is challenged by the th plate like boundary conditions of the dermal layer. Utilizing mathematical modeling, computational finite element modeling and tissue mimicking phantom fabrication, we aim to study the effect of these plate like boundary conditions on the ability to use SWEI to measure skin stiffness and thus quantify disease progression.

 

Acknowledgements: This work has been supported by NIH grants EB002132 and Dermatology Foundation. We thank the Ultrasound Division at Siemens Medical Solutions, USA, Inc. for their technical and in-kind support. We also thank Dr. Veronica Rotemberg for her help with patient imaging.

References:

[1] Fett N, et al: Academy of Dermatology, 64(2), pp. 231-242, quiz 243-234, 2011.

[2] Palmeri ML, et al: Interface Focus, 1(4), pp. 553-564, 2011.

[3] Nezafati KA, et al.: Archives of dermatology,147(9), pp.1112-1115, 2011.

[4] Palmeri ML, et al.: Journal of hepatology, 55(3), pp. 666-672, 2011.

 

A SWEI animation showing displacement in the "dermal" layer of a layered tissue mimicking PVA phantom. By measuring how fast this shear wave propagates laterally, we can reconstruct the stiffness of the tissue. 

SWEI Animation of Displacement in a Layered Tissue Mimicking Phantom