Tag: MRI scans

Visualising Multiple Sclerosis with a New MRI Procedure

This is a pseudo-colored image of high-resolution gradient-echo MRI scan of a fixed cerebral hemisphere from a person with multiple sclerosis. Credit: Govind Bhagavatheeshwaran, Daniel Reich, National Institute of Neurological Disorders and Stroke, National Institutes of Health

A key feature of multiple sclerosis (MS) is that it causes the patient’s own immune system to attack and destroy the myelin sheaths in the central nervous system. To date, it hasn’t been possible to visualise the myelin sheaths well enough to use this information for the diagnosis and monitoring of MS.  Now researchers have developed a new magnetic resonance imaging (MRI) procedure that maps the condition of the myelin sheaths more accurately than was previously possible.

The researchers successfully tested the procedure on healthy people for the first time, and published their results in Magnetic Resonance in Medicine.

In the future, the MRI system with its special head scanner could help doctors to recognise MS at an early stage and better monitor the progression of the disease.

This technology, developed by the researchers at ETH Zurich and University of Zurich, led by Markus Weiger and Emily Baadsvik from the Institute for Biomedical Engineering, could also facilitate the development of new drugs for MS. But it doesn’t end there: the new MRI method could also be used by researchers to better visualise other solid tissue types such as connective tissue, tendons and ligaments.

Quantitative myelin maps

Conventional MRI devices capture only inaccurate, indirect images of the myelin sheaths because these devices typically work by reacting to water molecules in the body that have been stimulated by radio waves in a strong magnetic field.

But the myelin sheaths, which wrap around the nerve fibres in several layers, consist mainly of fatty tissue and proteins. That said, there is some water – known as myelin water – trapped between these layers.

Standard MRIs build their images primarily using the signals of the hydrogen atoms in this myelin water, rather than imaging the myelin sheaths directly.

The ETH researchers’ new MRI method solves this problem and measures the myelin content directly.

It puts numerical values on MRI images of the brain to show how much myelin is present in a particular area compared to other areas of the image.

A number 8, for instance, means that the myelin content at this point is only 8 percent of a maximum value of 100, which indicates a significant thinning of the myelin sheaths.

Essentially, the darker the area and the smaller the number in the image, the more the myelin sheaths have been reduced.

This information ought to enable doctors to better assess the severity and progression of MS.

Measuring signals within millionths of a second

It is difficult however to image the myelin sheaths directly, since the signals that the MRI triggers in the tissue are very short-lived; the signals that emanate from the myelin water last much longer.

“Put simply, the hydrogen atoms in myelin tissue move less freely than those in myelin water. That means they generate much briefer signals, which disappear again after a few microseconds,” Weiger says, adding: “And bearing in mind a microsecond is a millionth of a second, that’s a very short time indeed.” A conventional MRI scanner can’t capture these fleeting signals because it doesn’t take the measurements fast enough.

To solve this problem, the researchers used a specially customised MRI head scanner that they have developed over the past ten years together with the companies Philips and Futura.

This scanner is characterised by a particularly strong gradient in the magnetic field.

“The greater the change in magnetic field strength generated by the three scanner coils, the faster information about the position of hydrogen atoms can be recorded,” Baadsvik says.

Generating such a strong gradient calls for a strong current and a sophisticated design.

As the researchers scan only the head, the magnetic field is more contained and concentrated than with conventional devices.

In addition, the system can quickly switch from transmitting radio waves to receiving signals; the researchers and their industry partners have developed a special circuit for this purpose.

The researchers have already successfully tested their MRI procedure on tissue samples from MS patients and on two healthy individuals. Next, they want to test it on MS patients themselves. Whether the new MRI head scanner will make its way into hospitals in the future now depends on the medical industry. “We’ve shown that our process works,” Weiger says. “Now it’s up to industry partners to implement it and bring it to market.”

Source: ETH Zurich

AI-based CT Scans of the Brain can Nearly Match MRI

Photo by Mart Production on Pexels

A new artificial intelligence (AI)-based method can provide as much information on subtle neurodegenerative changes in the brain captured by computed tomography (CT) as compared to magnetic resonance imaging (MRI). The method, reported in the journal Alzheimer’s & Dementia, could enhance diagnostic support, particularly in primary care, for conditions such as dementia and other brain disorders.

Compared to MRI, which requires powerful superconducting magnetics and their associated cryogenic cooling, computed tomography (CT) is a relatively inexpensive and widely available imaging technology. CT is considered inferior to MRI when it comes to reproducing subtle structural changes in the brain or flow changes in the ventricular system. Certain imaging must therefore currently be carried out by specialist departments at larger hospitals equipped with MRI.

AI trained on MRI images

Created with deep learning, a form of AI, the software has been trained to transfer interpretations from MRI images to CT images of the same brains. The new software can provide diagnostic support for radiologists and other professionals who interpret CT images.

“Our method generates diagnostically useful data from routine CT scans that, in some cases, is as good as an MRI scan performed in specialist healthcare,” says Michael Schöll, a professor at Sahlgrenska Academy who led the work involved in the study, carried out in collaboration with researchers at Karolinska Institutet, the National University of Singapore, and Lund University

“The point is that this simple, quick method can provide much more information from examinations that are already carried out on a routine basis within primary care, but also in certain specialist healthcare investigations. In its initial stage, the method can support dementia diagnosis, however, it is also likely to have other applications within neuroradiology.”

Reliable decision-making support

This is a well-validated clinical application of AI-based algorithms, and has the potential to become a fast and reliable form of decision-making support that effectively reduces the number of false negatives. The researchers believe that this solution can improve diagnostics in primary care, optimising patient flow to specialist care.

“This is a major step forward for imaging diagnosis,” says Meera Srikrishna, a postdoctor at the University of Gothenburg and lead author of the study.

“It is now possible to measure the size of different structures or regions of the brain in a similar way to advanced analysis of MRI images. The software makes it possible to segment the brain’s constituent parts in the image and to measure its volume, even though the image quality is not as high with CT.”

Applications for other brain diseases

The software was trained on images of 1117 people, all of whom underwent both CT and MRI imaging. The current study mainly involved healthy older individuals and patients with various forms of dementia. Another application that the team is now investigating is for normal pressure hydrocephalus (NPH).

With NPH, the team has obtained new results indicating that the method can be used both during diagnosis and to monitor the effects of treatment. NPH is a condition that occurs particularly in older people, whereby fluid builds up in the cerebral ventricular system and results in neurological symptoms. About two percent of all people over the age of 65 are affected. Because diagnosis can be complicated and the condition risks being confused with other diseases, many cases are likely to be missed.

“NPH is difficult to diagnose, and it can also be hard to safely evaluate the effect of shunt surgery to drain the fluid in the brain,” continues Michael. “We therefore believe that our method can make a big difference when caring for these patients.”

The software has been developed over the course of several years, and development is now continuing in cooperation with clinics in Sweden, the UK, and the US together with a company, which is a requirement for the innovation to be approved and transferred to healthcare.

Source: University of Gothenburg

MRI Scan Combination Could Detect Hypertrophic Cardiomyopathy Early

Credit: Pixabay CC0

Combining two types of heart scan techniques could help detect hypertrophic cardiomyopathy (HCM) before symptoms and signs on conventional tests appear, according to a new study led by UCL researchers. To do this, they used two cutting-edge heart scanning techniques: cardiac diffusion tensor imaging (cDTI), which shows the heart’s microstructure and cardiac MRI perfusion (perfusion CMR), which reveals microvascular disease. Their findings, published in Circulation, will help doctors select appropriate treatments.

HCM is a disease which affects around 1 in 500 in the UK, causing thickening of heart muscle and can lead to heart failure and cardiac arrest.

Researchers studied the hearts of three groups: healthy people, people who already had HCM, and people with an HCM-causing genetic mutation but no overt signs of disease.

The scans showed that people with overt signs of HCM have very abnormal organisation of their heart muscle cells and a high rate and severity of microvascular disease compared to healthy volunteers, helping doctors more accurately spot the early signs of HCM.

Crucially, the scans were also able to identify abnormal microstructure and microvascular disease in the people who had a problematic gene but no symptoms or muscle thickening. They found that 28% had defects in their blood supply, compared to healthy volunteers. This meant that doctors were able to more accurately spot the early signs of HCM developing in patient’s hearts.

The first drug to slow HCM progression, mavacamten, has recently been approved for use in Europe and will allow doctors to reduce the severity of the disease once symptoms and muscle thickening have appeared. Genetic therapies are also in development which could prevent symptoms entirely by intercepting HCM development at an early stage.

Perfusion CMR is already being used in some clinics to help differentiate people with HCM from other causes of muscle thickening. The researchers think that these revolutionary new therapies, combined with cDTI and perfusion CMR scans, give doctors the best ever chance of treating people at risk of HCM early enough that the condition never develops.

Dr George Joy, who led the research with Professor James Moon and Dr Luis Lopes (all UCL Institute of Cardiovascular Science), said: “The ability to detect early signs of HCM could be crucial in trials testing treatments aimed at preventing early disease from progressing or correcting genetic mutations. The scans could also enable treatment to start earlier than we previously thought possible.

“We now want to see if we can use the scans to identify which patients without symptoms or heart muscle thickening are most at risk of developing severe HCM and its life-changing complications. The information provided from scans could therefore help doctors make better decisions on how best to care for each patient.”

Dr Luis Lopes (UCL Institute of Cardiovascular Science), senior author of the study, said: “By linking advanced imaging to our cohort of HCM patients (and relatives) with extensive genetic testing, this study detected microstructural abnormalities in vivo in mutation carriers for the first time and was the first to compare these parameters in HCM patients with and without a causal mutation.

“The findings allow us to understand more about the early subclinical manifestations of this serious condition but also provide additional clinical tools for screening, monitoring and hopefully in the near future for therapeutic decision-making.”

Source: University College London

Greater Precision with MRI-guided Prostate Cancer Radiotherapy

Credit: Darryl Leja / National-Human-Genome Research Institute / National Institutes of Health

Men undergoing MRI-guided radiotherapy for localised prostate cancer, had fewer toxicities and better quality of life, according to new research published in JAMA Oncology. This was the first randomised phase III clinical trial to directly compare MRI-guided stereotactic body radiotherapy (SBRT) with the same therapy guided by CT.

“MRI guidance offers several advantages over standard CT guidance, most notably the ability to dramatically reduce planning margins, providing more focused treatment with less injury to nearby normal tissues and organs,” said lead author Amar Kishan, MD, a radiation oncologist. “MRI technology is more costly than CT, both in terms of upfront equipment expenses and longer treatment times, which is one reason our study set out to determine if MRI-guided technology offers tangible benefits for patients.”

SBRT for prostate cancer usually delivers radiation in five or fewer precisely targeted doses. It is an established and generally well tolerated form of treatment, but it can cause toxicities resulting in urinary, bowel and sexual dysfunction. This UCLA-led clinical trial included 154 analysable patients with prostate cancer who were randomised to either a CT-guidance arm (76 patients) or an MRI-guidance arm (78 patients).

This study included assessment by both physicians and patients. From both perspectives, MRI-guided therapy was associated with fewer side effects and better quality of life over at least three months of follow-up.

“In this trial, we demonstrated that the reduction in treatment volumes facilitated by MRI guidance leads to a significant reduction in moderate physician-scored toxicity and to a reduction in the proportion of patients noting significant decrements in patient-reported outcome metrics in the near term,” said Dr Kishan. “Although additional studies will need to confirm these benefits over time, we’re hopeful that these results will lead to better outcomes for men with prostate cancer.”

The 2mm margin used with MRI-guidance in the trial is narrower than has been used in any previous large study. Unlike CT, MRI technology can monitor prostate motion directly, and it offers improved soft tissue contrast, improving the accuracy of alignment prior to radiation.

Source: University of California – Los Angeles Health Sciences

MRI Reveals How a Dip in Cold Water Boosts Mood

Observations of the brain when the body is immersed in cold water reveal changes in connectivity between areas which process emotion, which could explain why people often feel more upbeat and alert after swimming outside or taking cold baths.

During a research trial, published in the journal Biology, 33 healthy volunteers were given a functional MRI (fMRI) scan immediately after bathing in cold water. The team included imaging experts from Bournemouth University and University Hospitals Dorset (UHD), and extreme environments researcher, Dr Heather Massey, from the University of Portsmouth. 

Dr Massey, from the School of Sport, Health and Exercise Science, said: “It has been a really pleasing experience to work with this interdisciplinary team to develop a method and publish this piece of research that could only be completed by a group with such a diverse skill set.

“With the growing popularity of outdoor swimming and cold water immersion, which many now use to support improved mood, it is long overdue that we study how it may affect us. We know so much about the impact cold water immersion can have on the body, but the brain has had little focus, primarily as it has been more challenging to study. It is only now that technology is developing, can we start to get some insight.”

Dr Ala Yankouskaya, Senior Lecturer in Psychology at Bournemouth University, led the study. She said: “The benefits of cold-water immersion are widely known from previous studies where participants were questioned on how they feel afterwards, but we wanted to see how the shock of going into the cold water actually affects the brain.” 

Each participant was given an initial fMRI scan and then immersed in a pool of water at 20°C for five minutes whilst an ECG and respiratory equipment measured their bodies’ physiological responses. After being quickly dried they were given a second fMRI scan so the team could look for any changes in their brains’ activity.

“All tiny parts of the brain are connected to each other in a certain pattern when we carry out activities in our day-to-day lives, so the brain works as a whole.” said Dr Yankouskaya. “After our participants went in the cold water, we saw the physiological effects – such as shivering and heavy breathing. The MRI scans then showed us how the brain rewires its connectivity to help the person cope with the shock.”  

Comparing the scans showed that changes had occurred in the connectivity between specific parts of the brain, in particular, the medial prefrontal cortex and the parietal cortex.

“These are the parts of the brain that control our emotions, and help us stay attentive and make decisions,” Dr Yankouskaya said. “So when the participants told us that they felt more alert, excited and generally better after their cold bath, we expected to see changes to the connectivity between those parts. And that is exactly what we found.”

The team are now planning to use their findings to understand more about the wiring and interactions between parts of the brain for people with mental health conditions. 

“The medial prefrontal cortex and parietal cortex have different wiring when people have conditions such as depression and anxiety,” Dr Yankouskaya explained.

“Learning how cold water can rewire these parts of the brain could help us understand why the connectivity is so different for people with these conditions, and hopefully, in the long-term, lead to alternative treatments,” she concluded.

Source: University of Portsmouth

A Severe Form of Dementia may in Fact be Caused by a Cerebrospinal Fluid Leak

MRI images of the brain
Photo by Anna Shvets on Pexels

A new study suggests that some patients diagnosed with behavioural-variant frontotemporal dementia (bvFTD) – a presently incurable, mentally debilitating condition – may instead have a cerebrospinal fluid leak, which is detectable on MRI scans and often treatable. The researchers say these findings, published in the peer-reviewed journal Alzheimer’s & Dementia: Translational Research and Clinical Interventionscould lead to a cure.

“Many of these patients experience cognitive, behavioural and personality changes so severe that they are arrested or placed in nursing homes,” said Wouter Schievink, MD, professor of Neurosurgery at Cedars-Sinai. “If they have behavioural-variant frontotemporal dementia with an unknown cause, then no treatment is available. But our study shows that patients with cerebrospinal fluid leaks can be cured if we can find the source of the leak.”

When cerebrospinal fluid (CSF) leaks into the body, the brain can sag, causing dementia symptoms. Schievink said many patients with brain sagging, detectable in MRI, go undiagnosed, and he advises clinicians to take a second look at patients with telltale symptoms.

“A knowledgeable radiologist, neurosurgeon or neurologist should check the patient’s MRI again to make sure there is no evidence for brain sagging,” Schievink said.

Clinicians can also ask about a history of severe headaches that improve when the patient lies down, significant sleepiness even after adequate night-time sleep, and whether the patient has ever been diagnosed with a Chiari brain malformation, a condition in which brain tissue extends into the spinal canal. Brain sagging, Schievink said, is often mistaken for a Chiari malformation.

Even when brain sagging is detected, the source of a CSF leak can be difficult to locate. When the fluid leaks through a tear or cyst in the surrounding membrane, it is visible on CT myelogram imaging with the aid of contrast medium.

Schievink and his team recently discovered an additional cause of CSF leak: the CSF-venous fistula. In these cases, the fluid leaks into a vein, making it difficult to see on a routine CT myelogram. To detect these leaks, technicians must use a specialized CT scan and observe the contrast medium in motion as it flows through the cerebrospinal fluid.

In this study, investigators used this imaging technique on 21 patients with brain sagging and symptoms of bvFTD, and they discovered CSF-venous fistulas in nine of those patients. All nine patients had their fistulas surgically closed, and their brain sagging and accompanying symptoms were completely reversed.

“This is a rapidly evolving field of study, and advances in imaging technology have greatly improved our ability to detect sources of CSF leak, especially CSF-venous fistula,” said Keith L. Black, MD, chair of the department of Neurosurgery at Cedars-Sinai. “This specialised imaging is not widely available, and this study suggests the need for further research to improve detection and cure rates for patients.”

The remaining 12 study participants, whose leaks could not be identified, were treated with nontargeted therapies designed to relieve brain sagging, such as implantable systems for infusing the patient with CSF. However, only three of these patients experienced relief from their symptoms.

“Great efforts need to be made to improve the detection rate of CSF leak in these patients,” Schievink said. “We have developed nontargeted treatments for patients where no leak can be detected, but as our study shows, these treatments are much less effective than targeted, surgical correction of the leak.”

Source: Cedars-Sinai Medical Center

PET/CT Scans Fail to Beat MRI for Prostate Cancer Detection

Credit: Darryl Leja / National-Human-Genome Research Institute / National Institutes of Health

Researchers found that MRI scans, the current gold standard, can still detect prostate cancer more accurately than the newer, prostate-specific -PSMA PET/CT scanning technique.

The findings were presented at the European Association of Urology’s annual congress (EAU22).

Prostate-specific membrane antigen (PSMA) PET/CT scans, approved by the US FDA in 2020, use a radioactive dye to highlight areas of PSMA, which is overexpressed on the surface of prostate cancer cells. Presently, these scans are used to manage prostate cancer, as they can accurately measure the progression or recurrence of the disease. The researchers set out to find if they could be used to diagnose prostate cancer as well.

The PEDAL trial recruited 240 patients at risk of prostate cancer, with each patient given both an MRI scan and a PSMA PET/CT scan. If imaging suggested the presence of prostate cancer, a biopsy was performed by the patient’s urologist.

The MRI scans picked up abnormalities in 141 patients, while the PSMA PET/CT scans picked up abnormalities in 198 patients. A total of 181 patients (75%) underwent a prostate biopsy, and subsequently 82 of those patients were found to have clinically significant prostate cancer.

The MRI scans were significantly more accurate at detecting any grade of prostate cancer than the PSMA PET scans.

The research team was led by Associate Professor Lih-Ming Wong, who explained: “Our analysis found that MRI scans were better than PSMA-PET for detecting any grade of prostate cancer. When we looked only at clinically significant prostate cancers, there was no difference in accuracy.  As this study is one of the first to explore using PSMA-PET to diagnose cancer within the prostate, we are still learning and adjusting how to improve using PSMA-PET in this setting.

Although detection thresholds will be  fine-tuned as diagnostic use develops,  Prof Wong believes the trial has important lessons for clinicians. 

He said: “This study confirms that the existing ‘gold standard’ of pre-biopsy detection – the MRI – is indeed a high benchmark. Even with fine-tuning, we suspect PSMA PET/CT won’t replace the MRI as the main method of prostate cancer detection. But it will likely have application in the future as an adjunct to the MRI, or for people for whom an MRI is unsuitable, or as a single combined “diagnostic and staging” scan for appropriately selected patients.”

Source: EurekAlert!

Scientists Discover a Difference in Brains of Psychopathic Individuals

Brain scan image
Image source: Mart Production on Pexels

Neuroscientists report in the Journal of Psychiatric Research that they have discovered a biological difference between psychopaths and non-psychopaths.

Using magnetic resonance imaging (MRI) scans, they found that a region of the forebrain known as the striatum was on average 10% larger in psychopathic individuals compared to a control group of individuals with low or no psychopathic traits.

Psychopaths, or those with psychopathic traits, are generally defined as individuals that have an egocentric and antisocial personality. It is a neuropsychiatric disorder marked by deficient emotional responses, lack of empathy, and poor behavioural controls, commonly resulting in persistent antisocial deviance and criminal behaviour. Accumulating research suggests that psychopathy follows a developmental trajectory with strong genetic influences, and which precipitates deleterious effects on widespread functional networks, particularly within paralimbic regions of the brain.

The striatum, which is a part of the forebrain, the subcortical region of the brain that contains the entire cerebrum, coordinates multiple aspects of cognition, including both motor and action planning, decision-making, motivation, reinforcement, and reward perception.

Previous studies had indicated an overly active striatum in psychopaths but had not conclusively determined the impact of its size on behaviours. The new study reveals a significant biological difference between people who have psychopathic traits and those who do not.

A better understanding of the role of biology in antisocial and criminal behaviour may help improve existing theories of behaviour, as well as inform policy and treatment.

Source: Nanyang Technical University

Scans of Brain Connectivity in Veterans Yield Objective Pain Measures

MRI images of the brain
Photo by Anna Shvets on Pexels

A brain connectivity study of military veterans discovered three unique brain subtypes potentially indicating high, medium, and low susceptibility to pain and trauma symptoms. This could constitute an objective measurement of pain and trauma susceptibility, possibly leading to personalised treatments and new therapies based on neural connectivity patterns.  

Comorbidity Goes Unexplored

“Chronic pain is a major public health concern, especially among veterans,” said first author Prof Irina Strigo. “Moreover, chronic pain sufferers almost never present with a single disorder but often with multiple co-morbidities, such as trauma, posttraumatic stress, and depression.”

It is already understood that both pain and trauma can affect brain connections, but this had not been studied in the context of comorbid trauma and pain. Much pain and trauma research also relies on subjective measurements, such as questionnaires, rather than objective measurements like brain scans. This study, published in Frontiers in Pain Research, addresses these problems.

Theresearchers studied a group of 57 veterans with both chronic back pain and trauma, who had quite varied symptoms in terms of pain and trauma severity. Functional MRI scans of the veterans’ brains showed the strength of connections between brain regions involved in pain and trauma. The researchers then used a statistical technique to automatically group the veterans based on their brain connection signatures, regardless of their self-reported pain and trauma levels.

Based on the veterans’ brain activity, they were sorted into three groups. Strikingly, these divisions were comparable to the severity of the veterans’ symptoms, and they fell into a low, medium, or high symptom group.

The team hypothesised that the pattern of brain connections found in the low symptom group allowed veterans to avoid some of the emotional fallout from pain and trauma, and also included natural pain reduction capabilities. Conversely, the high symptom group demonstrated brain connection patterns that may have increased their chances of anxiety and catastrophising when experiencing pain.

Interestingly, based on self-reported pain and trauma symptoms, the medium symptom group was largely similar to the low symptom group. However, the medium symptom group showed differences in their brain connectivity signature, which suggested that they were better at focusing on other things when experiencing pain, reducing its impact.

Putting the findings into future practice

“Despite the fact that the majority of subjects within each subgroup had a co-morbid diagnosis of pain and trauma, their brain connections differed,” said Prof Strigo.

“In other words, despite demographic and diagnostic similarities, we found neurobiologically distinct groups with different mechanisms for managing pain and trauma. Neurobiological-based subgroups can provide insights into how these individuals will respond to brain stimulation and psychopharmacological treatments.”

Thus far, it’s not known whether these neural hallmarks represent a vulnerability to trauma and pain or a consequence of these conditions. The technique does however provide an objective and unbiased hallmark of pain and trauma susceptibility or resilience, not reliant on subjective measures such as the surveys. In fact, subjective measurements of pain in this study would not differentiate between the low and medium groups.

Techniques using objective measures like brain connectivity appear more sensitive and could provide a clearer overall picture of someone’s resilience or susceptibility to pain and trauma, thereby guiding personalised treatment and paving the way for new treatments.

Source: Frontiers

Portable MRI Machines Extend Stroke Diagnosis Coverage

Credit: American Heart Association

Portable MRI machines, an emerging technology that makes medical imaging accessible even in remote locations, detected ischaemic strokes in 90% of patients scanned, according to a study appearing in the journal Science Advances.

In previous studies, portable MRI devices have demonstrated they can also detect haemorrhagic as well as ischaemic strokes, helping clinicians make crucial life-saving treatment decisions quickly in remote areas for patients who lack ready access to major hospitals with expensive stationary MRI machines, the authors say.

“This is the first systematic evidence you can detect ischaemic strokes using portable, bedside devices,” noted Kevin Sheth, professor of neurology and neurosurgery at Yale School of Medicine and co-corresponding author of the study.

Outcomes for stroke patients improve dramatically the quicker they receive treatment. But access to stationary MRI machines is limited for those who live far away from major hospitals or in developing countries. And even stroke patients who have access to major hospitals often have to wait for scans with stationary MRIs because of heavy demand for the equipment. Portable scans can be used at a patient’s bedside, in ambulances, or in remote clinics, Dr Sheth said.

In addition, quickly differentiating between different types of stroke is crucial for determining proper treatment, the researchers say. Ischaemic strokes are usually treated with blood thinners. But that course of treatment is dangerous for those who experience haemorrhagic strokes or strokes in which there is bleeding in the brain.

Analysing portable MRI scans from 50 patients at Yale New Haven Hospital, the Yale and Harvard researchers found that the results largely confirmed ischaemic stroke diagnoses made by stationary MRIs. For 45 of those patients, the portable MRI detected blood clots as small as 4mm in size.

Source: Yale University