IIT Madras researchers develop new technique to provide high-resolution ultrasound images

Ultrasonic imaging technique is used to capture real-time images inside the human body. It has a wide range of clinical applications in the diagnosis and treatment of medical conditions. The technique is widely used to diagnose the cause of pain, swelling, and infection in internal organs, and to examine the fetus in pregnant women.

The most important part of an ultrasound machine is a “beamformer”, which plays a major role in the final reconstructed image quality. Over the years, several techniques have been identified to improve the quality of the reconstructed image by changing the beamformer.

The team claims to have developed a new beamforming technique, which has been shown to outperform other existing techniques and provide the best image resolution across the entire field of view. The findings of their research have been published in a peer-reviewed journal Scientific Reports.

“This research could potentially facilitate several applications such as early detection and better diagnosis of diseases, detection of minute abnormalities in the human body such as kidney stones, better real-time image-guided biopsy procedures, and treatment monitoring applications,” Arun K Thittai, Professor, Department of Applied Mechanics , IIT Madras, told PTI.

Delay and Sum (DAS) beamformer is the most widely used ultrasound imaging technique in commercial systems due to its simplicity of hardware implementation. However, it has a low image resolution.

Recently, with improvements in computing capability, an alternative beamformer based on Filtered Delay Multiply and Sum (F-DMAS) technique was introduced to compensate for the drawbacks of the DAS. “On this basis, several similar techniques are being developed in research labs around the world. However, there were several drawbacks to these techniques including ‘low noise reduction’ where images are damaged with more noise which is amplified by the multiplicative effect of these existing techniques and ‘low contrast to noise ratio’ as if these techniques can improve resolution, they degrade the contrast,” said Anudeep Vayyeti, a research scientist at IIT Madras.

“These drawbacks make it challenging to detect small changes in the underlying tissue of the captured image, which could otherwise aid in early diagnosis of the disease. So we developed a new technique called Filtered Delay, Optimally Weighted Multiply and Sum (F-DowMAS), which will provide higher quality images compared to existing technologies,” he added.

The researchers claimed that the developed F-DowMAS technique can simultaneously improve both the resolution and contrast of an image, while also reducing noise levels in the reconstructed image to a greater extent in parallel.

“These improvements will help clinicians notice the smallest changes in anatomy, aiding early and better diagnosis of disease. The developed technique can also be easily integrated into existing commercial Ultrasound scanner platforms without the need for additional hardware changes, making this an economical and viable solution,” he said.