2D Contrast-Ultrasound Dispersion Imaging of Angiogenesis in Adenomyosis: First Experimental Measurements

Adenomyosis, a benign yet serious uterine condition, is highly prevalent but difficult to diagnose and assess using conventional B-mode ultrasound imaging. As the formation of adenomyosis involves angiogenesis and influences local microvascular dispersion, monitoring microvascularity could improve adenomyosis diagnostics. Hence, contrast-enhanced ultrasound (CEUS), a non-invasive imaging technique, is explored as an alternative to B-mode as it allows visualizing microvascularity. The goal is to investigate the potential of characterizing adenomyosis by quantifying surrogate measures of contrast dispersion, using the contrast-ultrasound dispersion imaging (CUDI) frame-work based on uterine CEUS. CUDI models the passage of an ultrasound-contrast-agent (UCA) bolus through the uterine tissue as a convective dispersion process and expresses UCA dispersion kinetics through temporal fitting
$(\kappa)$
and spatiotemporal similarity analysis. Before applying CUDI on clinical data, the speckle size is regularized to yield isotropy and depth-independence. In addition, the relationship between measured acoustic intensities and underlying UCA concentrations is determined to be linear
$(R^{2}=0.94)$
for SonoVue
^TM
UCA concentrations of 0.15-1.00 mg/L, allowing for the direct application of the proposed convective-dispersion modeling. After regularization, 2D CEUS acquisitions of one adenomyotic and one healthy uterus under-went CUDI analysis. The adenomyotic myometrium presented heterogeneously higher values of
$\kappa$
and spatiotemporal similarity, for the healthy uterus the values were homogeneous and lower. Since
$\kappa$
and spatiotemporal similarity are inversely proportional to the level of local dispersion, the results indicate the presence of angiogenesis in adenomyotic tissue, supported by the observations of heterogeneously decreased local dispersion.