Takayasu Arteritis Activity Evaluation by Ultrafast Ultrasound Imaging

Overview

The general activity of Takayasu vasculitis is correlated with the perfusion rate of the carotid arterial wall. This can be quantified with ultrafast ultrasound imaging in sensitive Doppler sequence associated with the concomitant injection of microbubbles (SonoVue®). The hypothesis is that the carotid artery wall flow parameters obtained with ultrafast ultrasound imaging make possible to discriminate an active disease from an inactive disease because of the fibrous sequential arterial thickening. Thus, to improve the evaluation of Takayasu vasculitis activity and to refine the criteria for response to the various immunomodulatory treatments used.

Takayasu vasculitis is a systemic inflammatory disease that causes progressive thickening and stenosis of large and medium-sized arteries (the aorta and its branches, as well as the pulmonary arteries). The classic histological aspect corresponds to a chronic inflammation localized to the arterial wall. Vascular imaging plays an important role in the diagnosis and monitoring of these patients. Although Doppler ultrasound, MRI and computed tomography can simply assess recognized inflammation criteria, such as thickening or signal intensity of the arterial wall, to recognize Takayasu vasculitis in the early stages of inflammation of the disease, there is no clear correlation between the presence of these signs and the activity or progression of the disease. However, assessment of Takayasu vasculitis activity is difficult in daily practice because symptoms, physical examination, and biological parameters may not reliably reflect vascular inflammation. Finally, unlike other small- and medium-vessel vasculitis, histology is rarely available to diagnose and evaluate the activity of patients with Takayasu vasculitis. In order to identify local markers of disease activity, contrast ultrasound (with injection of SonoVue® microbubbles) has shown its ability to visualize the presence of micro-vessels within the carotid wall. Ultrafast Ultrasound Imaging provides a more accurate exploration of the small vasorum vessels compared to contrast ultrasound. This technology has already been the subject of a study on cerebral microvasculature. In its application on the carotid wall, it will allow easier quantification than conventional ultrasound, by a signal analysis in ultrafast Doppler and not on the gray level, much more variable.