2D AND 3D IMAGING OF SUPERFICIAL MICRO-VESSELS USING HIGH-FREQUENCY ULTRAFAST ULTRASOUND

Author: Anam Bhatti
Time: 11H00
Language: English
Place: Conference Room at LabTAU

Abstract: 

In response to any cutaneous disease, the morphology and functionality of superficial vasculatures in skin being deteriorated. Superficial vasculatures are characterized as the tortuous and branched structures anastomosed around the diseased tissue. Therefore, visualization of these vessels plays a crucial role in diagnosis and prognosis of cutaneous disorders. Traditionally, high-frequency ultrasound has been used in dermatology for dermal morphological observation, its limited Doppler sensitivity poses challenges for micro-vessels visualization. This study addresses this limitation by employing the ultrafast acquisition techniques of ultrasound and advanced clutter filtering approaches based on singular value decomposition to map the micro-circulation in dermal superficial vasculatures effectively in 2D and 3D imaging.

A novel approach using region-based SVD clutter filtering was proposed to extract the blood flow signals in vasculatures of different dimensions, densities, and flow speed across different layers of the skin. Additionally, a 3D volumetric imaging method was introduced to visualize the superficial vasculatures from various perspectives, using continuous mechanical translation to scan the imaging area and the section-wise region-based SVD processing was proposed to extracts the blood flow signal efficiently. Post-processing algorithms such as top-hat transform morphological filter and non-local means filter were implemented to remove the noises and enhance the image quality.

The effectiveness of the proposed approaches was evaluated using custom-designed micro-flow phantoms mimicking different types of superficial micro-vessels. In-vivo experiments on healthy subject demonstrated the visualization of micro-vessels with a minimum diameter of 51 μm in the dermal layers. Acquired in-vitro and in-vivo results highlights the efficacy of the proposed 2D and 3D approaches to visualize the superficial micro-vessels for an effective diagnosis of cutaneous diseases.