Around four decades ago, Stuart Crozier, an Australian inventor of 30 patented magnetic resonance imaging (MRI) technologies, secured a vacation placement in the biomedical engineering department at Brisbane’s Princess Alexandra Hospital.
During his placement, Crozier saw engineers creating devices to help spinal-injury patients perform basic actions like lifting a cup which inspired him to focus on technology that benefits patients.
Passion to make a difference
Following graduation and further studies in medical physics, he worked as a biomedical engineer and medical physicist across several hospitals.
This led him to a research position in biomedical engineering with an MRI research group — led by Professor David Doddrell — at the Mater Hospital in the late 1980s. The first commercial MRIs had just come to market when he began his doctorate work and, “while the tissue contrast was spectacular compared to CT, the signal-to-noise ratio (SNR) was considerably lower than it is now and there were several artefacts that limited image quality”. Crozier completed his PhD with the same MRI research group.
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The centre moved to The University of Queensland (UQ) and a milestone was the group’s invention of a signal correction technology that corrected magnetic field distortions, producing faster, clearer and more accurate MRI images without increasing costs.
“Two-thirds of the world’s clinical MRI machines use this signal correction technology, improving the quality of diagnosis at an earlier stage of disease and increasing the success rate of early medical intervention. In the 35 years since, the MRI research undertaken at UQ has led to multiple commercial successes, with proceeds from our initial innovations funding further research and breakthroughs.
“My research has always focused on designing or improving diagnostic medical devices that fill a clinical need. It is essential to work closely with clinicians and to canvas the areas where new innovations are needed.”
Fuelling innovation and progress
Over the past four decades, MRI and other imaging modalities have progressed significantly with massive improvements in CT, ultrasound and other modalities, expanding their use cases and improving safety, usability and diagnostic information, Crozier said.
“Ultrasound technology, for example, has seen a remarkable transformation. The advent of portable and user-friendly devices has expanded its reach beyond traditional clinical settings.
“Handheld ultrasound devices can now generate high-resolution 3D and 4D foetal images, significantly enhancing prenatal care, and the development of ultrasound contrast agents is pushing the boundaries of this modality.
“In MRI, the advent of high field systems (and now almost helium-free) allowed improved SNR as well as the ability to use stronger gradients without artefacts, something I am pleased to have had a small part in by way of the method mentioned above. Phased array radiofrequency coils opened the door to parallel imaging and when combined with compressed sensing enabled great reductions in imaging time such that cardiac imaging, for example, became a clinically useful MR method.
“The rise of deep learning (aka AI) denoising and other applications has revived interest in low-field imaging and improved the quality of low- and higher-field images and applications. Also, new methods are emerging using different types of signals to make diagnoses that perhaps were not previously viable.
“The exponential rise in computing power has enabled some of these new methods. I am particularly excited about electromagnetic microwave imaging given my involvement with EMVision Medical Devices,” Crozier said, who is a co-inventor of the EMVision imaging technology and now works as the company’s Chief Scientific Officer.
Reducing costs and improving access
There is considerable interest in trying to reduce the cost of imaging modalities and also to make them more accessible to those outside of large metropolitan areas. This is where the technology being developed by EMVision and Magnetica (another company Crozier is involved in) and others can play an important role, Crozier said.
“The miniaturisation of diagnostic tools will enable point-of-care testing, bringing critical health assessments closer to patients, possibly in resource-limited settings.”
EMVision is focused on developing a cost-effective, portable device using electromagnetic microwave imaging for diagnosis and monitoring of stroke and other medical applications.
“The technology is born out of over 10 years of research and development by researchers at The University of Queensland (UQ), which I contributed to alongside Professor Amin Abbosh, who led the group. It is aimed at providing point-of-care and immediate imaging of stroke or brain injury in settings where access to CT or MRI may be limited; for example, in an ambulance or in an ICU,” Crozier said.
He is particularly excited about the potential impact of in-home blood tests or portable brain diagnostics for rural communities. For example, emu — their portable, trolley-based, first responder device, targeted for use in road and air ambulances.
The device, designed to deliver prehospital stroke diagnosis and enable more timely care for patients irrespective of their location, is undergoing prototype development. It is currently progressing through clinical trials at major stroke centres in Australia and will be the company’s first device on the market.
“Early diagnosis and therefore earlier treatment is known to drastically improve patient outcomes in stroke, as does regular monitoring during treatment and post-operative recovery,” said Crozier, emphasising that in his role as the CSO he is responsible for the strategic direction, oversight and execution of the research and development efforts that underpin the company’s devices, as well as working closely with academic colleagues and clinical partners to bring these products to market.
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Illuminating the future of imaging
Commenting on the advancements in imaging, Crozier said, “Several research groups are combining imaging modalities to give synergistic advantages. For example, MR-PET systems allow fine anatomical detail from the MR images while the PET images allow functional oncological imaging to check for metastatic spread in cancer patients. This both reduces the number of visits patients need to make and adds greater accuracy and fidelity to the diagnostic information. Similarly, image-guided therapy is an exciting, combined modality.
“I was fortunate to be part of the Australian MR-Linac program where we developed a novel split 1T MR system with an integrated linear accelerator that could be guided by the rapid MR images to enable more accurately localised radiation therapy, particularly for organs that are moving during treatment due to breathing or peristalsis. This system is in use at the Ingham Institute at Liverpool Hospital.
“Of course, deep learning and other similar methods have a growing role to play but their application must be carefully verified and validated.”
Overcoming challenges
The rise in chronic diseases, cancer and an aging population are all driving demand for imaging, Crozier said.
“This puts pressure on a workforce already experiencing shortages. Interpreting complex scans can be subjective and time-consuming, with the potential for missing subtle abnormalities. Telemedicine-enabled devices allow specialists in large tertiary hospitals to contribute to patient care outside large cities.
“Artificial intelligence (AI) presents a promising solution to automate repetitive tasks and streamline workflows, potentially assisting radiologists in triaging those cases with the highest urgency.
“Equity of access is another area of concern. High costs associated with advanced imaging can significantly limit access for patients in low- and middle-income countries, or even within developed nations.
“Lack of specialist resources, such as radiographers, to operate the advanced imaging equipment can also be a challenge. Ensuring more affordable, easier to use and portable imaging devices make it to market will be crucial to bridging this gap,” Crozier concluded.
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