# Double Profile Intersection (DoPIo) Ultrasound With Acoustic Radiation Force Tilting Interrogates Young’s Modulus in Transversely Isotropic Media: An In Silico Study

## TL;DR

This study explores a new ultrasound technique to measure both shear and Young’s elastic moduli in anisotropic tissues like kidney and muscle using a novel angle-based approach.

## Contribution

A new method to interrogate Young’s modulus in anisotropic tissues using DoPIo ultrasound and ARF tilting.

## Key findings

- DoPIo measurements at 90° ARF-AoS incidence correlate with shear modulus only.
- Variation in DoPIo elasticity with ARF-AoS angle correlates linearly with Young’s modulus.
- The rate of change of elasticity with angle can serve as a biomarker for anisotropic tissues.

## Abstract

This study evaluates the potential for interrogating the Young’s elastic moduli in anisotropic media, including tissue, using Double Profile Intersection (DoPIo) ultrasound. DoPIo is an on-axis acoustic radiation force (ARF)-based elasticity imaging method that quantifies shear elasticity without relying on shear wave propagation. It is hypothesized that by applying a range of ARF excitations that are not perpendicular to the axis of symmetry (AoS) of transversely isotropic (TI) materials and monitoring the resultant variation in DoPIo-measured elasticity versus excitation angle, the Young’s elastic modulus may be interrogated in addition to the shear elastic modulus. The hypothesis was tested in silico, and results suggested that while DoPIo outcomes measured at normal (90°) ARF-AoS incidence were related to the shear elastic modulus alone, variation in DoPIo-derived elasticity over ARF-AoS incidence angle (defined as ΔElasticity) exhibited a strong linear correlation with the longitudinal Young’s modulus (EL). The results suggest that EL evaluated by the rate of change of ΔElasticity with ARF-AoS incidence angle may serve as a novel biomarker for characterizing elastically anisotropic tissues such as kidney, skeletal muscle, and breast.