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Tag Archives: Medical Imaging

Scientists Design Skin Patch That Takes Ultrasound Images

The future of ultrasound imaging could be a sticker affixed to the skin that can transmit images continuously for 48 hours.

Researchers at Massachusetts Institute of Technology (MIT) have created a postage stamp-sized device that creates live, high-resolution images. They reported on their progress this week.

“We believe we’ve opened a new era of wearable imaging: With a few patches on your body, you could see your internal organs,” said co-senior study author Xuanhe Zhao, a professor of mechanical engineering and civil and environmental engineering at MIT.

The sticker — about 3/4-inch across and about 1/10-inch thick — could be a substitute for bulky, specialized ultrasound equipment available only in hospitals and doctor’s office, where technicians apply a gel to the skin and then use a wand or probe to direct sound waves into the body.

The waves reflect back high-resolution images of a major blood vessels and deeper organs such as the heart, lungs and stomach. While some hospitals already have probes affixed to robotic arms that can provide imaging for extended periods, the ultrasound gel dries over time.

For now, the stickers would still have to be connected to instruments, but Zhao and other researchers are working on a way to operate them wirelessly.

That opens up the possibility of patients wearing them at home or buying them at a drug store. Even in their current design, they could eliminate the need for a technician to hold a probe in place for a long time.

In the study, the patches adhered well to the skin, enabling researchers to capture images even if volunteers moved from sitting to standing, jogging and biking.

“We envision a few patches adhered to different locations on the body, and the patches would communicate with your cellphone, where AI algorithms would analyze the images on demand,” Zhao explained in an MIT news release.

A different approach tested — stretchable ultrasound probes — yielded images with poor resolution.

“[A] Wearable ultrasound imaging tool would have huge potential in the future of clinical diagnosis. However, the resolution and imaging duration of existing ultrasound patches is relatively low, and they cannot image deep organs,” said co-lead author Chonghe Wang, a graduate student who works in Zhao’s Lab.

The MIT team’s new ultrasound sticker produces higher resolution images by pairing a stretchy adhesive layer with a rigid array of transducers (they convert energy from one form to another). In the middle is a solid hydrogel that transmits sound waves. The adhesive layer is made from two thin layers of elastomer.

“The elastomer prevents dehydration of hydrogel,” co-lead author Xiaoyu Chen explained. “Only when hydrogel is highly hydrated can acoustic waves penetrate effectively and give high-resolution imaging of internal organs.”

Healthy volunteers wore the stickers on various areas, including the neck, chest, abdomen and arms. The stickers produced clear images of underlying structures, including the changing diameter of major blood vessels, for up to 48 hours. They stayed attached while volunteers sat, stood, jogged, biked and lifted weights.

They showed how the heart changes shape as it exerts during exercise and how the stomach swells, then shrinks, as volunteers drank and then eliminated juice. Researchers also could detect signs of temporary micro-damage in muscles as volunteers lifted weights.

“With imaging, we might be able to capture the moment in a workout before overuse, and stop before muscles become sore,” Chen said. “We do not know when that moment might be yet, but now we can provide imaging data that experts can interpret.”

In addition to working on wireless technology for the stickers, the team is developing software algorithms based on artificial intelligence that can better interpret the ultrasound images.

Zhao thinks patients may one day be able to buy stickers that could be used to monitor internal organs, the progression of tumors and development of fetuses in the womb.

“We imagine we could have a box of stickers, each designed to image a different location of the body,” Zhao said. “We believe this represents a breakthrough in wearable devices and medical imaging.”

The findings were published in Science.

Source: HealthDay

HKU Electrical and Electronic Engineering Researchers Make MRI Technology Accessible to Large Populations Worldwide

Magnetic resonance imaging (MRI) technology is a widely used albeit costly tool for diagnosing brain injuries and strokes. Its high procurement, installation and operating costs, however, mean much of the developing world has no access to it.

Researchers from the University of Hong Kong (HKU) have successfully developed a new magnetic resonance imaging (MRI) technology, the ultralow field (ULF) 0.055 Tesla brain MRI, which can operate from a standard AC wall power outlet and requires neither radiofrequency nor magnetic shielding room.

The research team was led by Professor Ed X. Wu, Chair of Biomedical Engineering and Lam Woo Professorship in Biomedical Engineering of the Department of Electrical and Electronic Engineering, HKU. The research output was published in Nature Communications, and also highlighted in Nature Asia and Scientific American.

The HKU team is one of the three leading ULF-MRI academic research groups worldwide, with one based at Harvard/MGH, dedicated to developing novel ULF-MRI technology. Their goal, as shared by researchers like Professor Wu, is to popularise and broaden the use of MRI.

As an MRI researcher for over 30 years, Professor Wu is delighted and derives a strong sense of fulfilment from the development of what he calls a “scaled down” MRI scanner that is far more affordable than what is on offer in hospitals. The human body is mostly made of water molecules, on which MRI thrives, said Professor Wu. “MRI is a gift from nature and we must use it more. Currently, it is underutilised as a diagnostic tool.”

It is estimated that currently more than 90% of MRI scanners are located in high-income countries, and two-thirds of the world’s population do not have access to them. The total number of clinical scanners is estimated at only about 50,000 worldwide.

Professor Wu’s team has made the design and algorithms of ULF 0.055 Tesla brain MRI open-source knowledge, available to all interested in developing the technology further or applying it in diverse areas.

This virtually opens the door to making advancement in various aspects of healthcare provision in terms of MRI applications. “This will be a big field; we have demonstrated the concept and shown the feasibility of a simplified version of MRI. There are many ways to move forward.”

With the use of a deep learning algorithm, Professor Wu’s team has removed the constraint in conventional MRI, namely the need to be shielded from outside radiofrequency signal, which results in a bulky, non-mobile set-up. The existing MRI scanners are essentially a giant magnet, and need a purpose-built room to shield them from outside signals and to contain the powerful magnetic fields generated by their superconducting magnets, which require costly liquid helium cooling systems.

“In short, it is our new computing and hardware concept that made the latest development possible,” said Professor Wu.

He is confident that a critical mass of researchers could push the frontiers of knowledge. “Open source approach is the quickest way to spread knowledge. We hope MRI can be used in more fields other than radiology, for example in paediatrics, neurosurgery or the emergency room. We welcome more people from the scientific, clinical and industrial sectors to undertake research to benefit healthcare,” he said.

In collaboration with Professor Gilberto Leung of Neurosurgery and other clinicians at Queen Mary Hospital, his team had validated the results of using ULF-MRI by comparing them with images obtained from a standard 3 Tesla MRI machine. They could identify most of the same pathologies, including stroke and tumors results, despite the lack of clarity and resolution required for precision diagnostics.

A conventional, typical MRI machine can cost up to US$3 million, yet the ULF-MRI scanner costs only a fraction of this price.

Professor Wu said: “I believe computing and big data will be an integral as well as inevitable part of the future MRI technology. Given the inherent nature of MRI, I believe widely deployed MRI technologies will lead to immense opportunities in the future through data-driven MRI image formation and diagnosis in healthcare. This will lead to low-cost, effective, and more intelligent clinical MRI applications, ultimately benefiting more patients.”

The paper, “A low-cost and shielding-free ultra-low-field brain MRI scanner” was published in Nature Communications.

Read the paper . . . . .

Source : HKU

Quantum Brain Sensors Could Spot Dementia

Alice Ingall wrote . . . . . . . . .

New highly sensitive quantum sensors for the brain may in the future be able to identify brain diseases such as dementia, ALS and Parkinson’s, by spotting a slowing in the speed at which signals travel across the brain. The research findings from a paper led by University of Sussex quantum physicists are published in Scientific Reports journal.

The quantum scanners being developed by the scientists can detect the magnetic fields generated when neurons fire. Measuring moment-to-moment changes in the brain, they track the speed at which signals move across the brain. This time-element is important because it means a patient could be scanned twice several months apart to check whether the activity in their brain is slowing down. Such slowing can be a sign of Alzheimer’s or other diseases of the brain.

In this way, the technology introduces a new method to spot bio-markers of early health problems.

Aikaterini Gialopsou, a doctoral researcher in the School of Mathematical and Physical Sciences at the University of Sussex and Brighton and Sussex Medical School is the lead author on the paper. She says of the discovery:

“We’ve shown for the first time that quantum sensors can produce highly accurate results in terms of both space and time. While other teams have shown the benefits in terms of locating signals in the brain, this is the first time that quantum sensors have proved to be so accurate in terms of the timing of signals too.

“This could be really significant for doctors and patients concerned with the development of brain disorders.”

These quantum sensors are believed to be much more accurate than either EEG or fMRI scanners, due in part to the fact that the sensors can get closer to the skull. The closer proximity of the sensors to the brain can not only improve the spatial, but also the temporal resolution of the results. This double improvement of both time and space accuracy is highly significant as it means brain signals can be tracked in ways that are inaccessible to other types of sensors.

“It’s the quantum technology which makes these sensors so accurate”, explains Professor Peter Kruger, who leads the Quantum Systems and Devices lab at the University of Sussex. He adds:

“The sensors contain a gas of rubidium atoms. Beams of laser light are shone at the atoms, and when the atoms experience changes in a magnetic field, they emit light differently. Fluctuations in the emitted light reveal changes in the magnetic activity in the brain. The quantum sensors are accurate within milliseconds, and within several millimetres.”

The technology behind the scanners is called magnetoencephalography (MEG). Combining MEG tech with these new quantum sensors has developed a non-invasive way to probe activity in the brain. Unlike existing brain scanners – which send a signal into the brain and record what come back – MEG passively measures what is occurring inside from the outside, eliminating the health risks currently associated for some patients with invasive scanners.

Currently MEG scanners are expensive and bulky, making them challenging to use in clinical practice. This development of quantum sensor technology could be crucial for transferring the scanners from highly controlled laboratory environments into real-world clinical settings.

“It’s our hope with this development” adds Gialopsou. “That in discovering this enhanced function of quantum brain scanners the door is opened to further developments that could bring about a quantum revolution in neuroscience. This matters because, although the scanners are in their infancy, it has implications for future developments that could lead to crucial early diagnosis of brain diseases, such as ALS, MS and even Alzheimer’s. That’s what motivates us as a team.”

Source: University of Sussex