Device and method for estimating blood vessel blood flow velocity field through transcranial ultrasound

Abstract

The invention discloses a device and a method for estimating a blood flow velocity field of a blood vessel through transcranial ultrasound. The device mainly comprises a low-frequency ultrasonic transducer, a programmable ultrasonic platform and a computer. The method is characterized in that the low-frequency ultrasonic transducer is used for transmitting a plane wave attached with a linear frequency modulation signal for imaging; space-time filtering on the radio frequency data, positioning and tracking radiography microbubbles are performed to obtain a blood vessel structure diagram, and the diameter and position coordinates of the blood vessel are confirmed; and a traditional image cross-correlation algorithm and a fast Fourier transform algorithm are combined and applied to speed distribution estimation. The method can effectively overcome the weakening of the echo signal intensity caused by transcranial ultrasonic attenuation, can accurately determine the blood vessel position area under the condition that the imaging resolution of the low-frequency ultrasonic transducer is low, and is particularly suitable for estimating the blood flow velocity distribution of the transcranial ultrasonic small blood vessel.

Description

technical field [0001] The invention belongs to the technical field of acoustic measurement, and relates to a device for estimating a vascular blood flow velocity field by using ultrasonic imaging and a corresponding blood flow velocity field estimation method. Background technique [0002] Cerebral small vessel disease has great damage to human body, cognition and spirit. Therefore, it is necessary to understand and master the parameters reflecting the physiological and pathological changes of cerebral small vessel disease in the basic research and diagnosis and treatment of cerebral small vessel disease. and data. Vascular blood flow velocity field refers to the spatial distribution of blood flow velocity on the radial section of the vessel. In fluid mechanics, the vessel lumen is approximated to a circular tube, and the flow of blood in the vessel conforms to the laminar flow in the circular tube. The vascular blood flow velocity field It presents a parabolic shape, and ...

AI Technical Summary

Problems solved by technology

However, transcranial ultrasound imaging is blocked by the skull. Although the signal can be enhanced by releasing contrast microbubbles in blood vessels, due to the half-wavelength limitation and the influence of sound wave attenuation after cranial penetration, it is impossible to obtain high-resolution ultrasound images and effectively distinguish blood vessels. Therefore, it is not suitable for estimating the blood flow velocity field of small cerebral blood vessels such as transcranial submillimeter vessels (vessels with a diameter of 0.1 to 1 mm) and microvessels (vessels with a diameter of less than 0.1 mm).

In addition, the traditional ultrasonic imaging scanning method is line scanning, that is, the ultrasonic transducer transmits signals one by one according to the arrangement of the array elements and receives echo signals one by one. This scanning method will cause the signals received by the array elements to be not at the same time. The problem of insufficient frame rate affects the acquisition of blood flow signals

[0004] At present, it is difficult to use ultrasound to identify small cerebral blood vessels and complete the estimation of the blood flow velocity field. Estimation of Blood Flow Velocity Distribution Using Ultrasonic Speckle Image Velocimetry in Blood Vessels

Chinese Patent CN107753062A "Transcranial Ultrasonic Cerebral Angiography Super-resolution Imaging Method Based on Markov Chain Monte Carlo Multi-target Tracking", Chinese Patent CN107714091A "Transcranial Low-Frequency Ultrasonic Chirp Reversal Microbubble Imaging Method" mentioned The imaging method effectively obtains the cerebral vascular structure map, but the cerebral vascular structure map is only a line graph formed by the connection of microbubble tracking points, which does not contain physical information, and cannot be used as an object for estimating the blood flow velocity distribution by the ultrasonic speckle image velocimetry method

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