People with pacemakers or implantable defibrillators have long been told they can’t undergo MRI scans. But a new study suggests that it can be safely done — under the right conditions.

The study, published in the Feb. 23 issue of the New England Journal of Medicine, focused on patients with standard heart devices not designed to be MRI-compatible.

The study found that even for them, an MRI can be safely performed, when a specific protocol is followed. [Read more…]

A new, specially coated iron oxide nanoparticle developed by a team at MIT and elsewhere could provide an alternative to conventional gadolinium-based contrast agents used for magnetic resonance imaging (MRI) procedures. In rare cases, the currently used gadolinium agents have been found to produce adverse effects in patients with impaired kidney function.

The advent of MRI technology, which is used to observe details of specific organs or blood vessels, has been an enormous boon to medical diagnostics over the last few decades. About a third of the 60 million MRI procedures done annually worldwide use contrast-enhancing agents, mostly containing the element gadolinium. While these contrast agents have mostly proven safe over many years of use, some rare but significant side effects have shown up in a very small subset of patients. There may soon be a safer substitute thanks to this new research. [Read more…]

A follow-up MRI scan after a mid-pregnancy ultrasound could help improve diagnosis of a possible fetal brain abnormality, a new British study reports.

Women selected for this study had undergone an ultrasound at 18 to 21 weeks of pregnancy that detected a potential brain abnormality in the fetus.

The extra information provided by the follow-up MRI helped doctors give a more accurate diagnosis and advice, according to the study authors.

The study was published Dec. 14 in The Lancet. [Read more…]

fMRI scans revealed activation of decision-making areas of the brain. Experts examining fMRI scans were 24 percent more likely to spot a lie. This is compared with the results of professional polygraph examiners.

Sweaty palms and a racing heartbeat might help you to spot a liar, but the most tell-tale evidence lies in the brain.

For the first time, researchers have conducted a controlled comparison of fMRI scans and polygraph testing in lie detection.

The study revealed fMRI is a far more effective method, as it picks up on the activation of decision-making areas in the brain when a person tells a lie, allowing it to identify deception up to 90 percent of the time.

[Read more…]

In a potentially important finding for the future of prosthetics, scientists at Oxford University showed that people who had their hands amputated even decades ago still maintain the representation of those hands in their brains. Scientists have long suspected that areas of the brain that end up not being used eventually forget how to do the things they previously knew. This latest study in journal eLIFE strongly suggests that this is not the case. [Read more…]

A new study by investigators at Brigham and Women’s Hospital in collaboration with researchers at the University of York and Leeds in the UK and MD Andersen Cancer Center in Texas puts to the test anecdotes about experienced radiologists’ ability to sense when a mammogram is abnormal. In a paper published August 29 in the Proceedings of the National Academy of Sciences, visual attention researchers showed radiologists mammograms for half a second and found that they could identify abnormal mammograms at better than chance levels. They further tested this ability through a series of experiments to explore what signal may alert radiologists to the presence of a possible abnormality, in the hopes of using these insights to improve breast cancer screening and early detection. [Read more…]

A new nuclear magnetic resonance (NMR) microscope gives researchers an improved instrument to study fundamental physical processes. It also offers new possibilities for medical science—for example, to better study proteins in Alzheimer’s patients’ brains. The development has been reported in Physical Review Applied.

If you get a knee injury, physicians use an MRI machine to look into the joint and determine the problem. The body’s atomic nuclei are electrically charged and spin around their axis. Just like small electromagnets, they induce their own magnetic field. By placing the knee in a uniform magnetic field, the nuclei line up with their axis, pointing in the same direction. The MRI machine then sends specific radio waves through the knee, causing some axes to flip. After terminating this signal, those nuclei flip back under excitation of a small radio wave. Those waves reveal the atoms’ location, and provide physicians with an accurate image of the knee. [Read more…]

The most sophisticated, widely adopted, and important tool for looking at living brain activity actually does no such thing. Called functional magnetic resonance imaging, what it really does is scan for the magnetic signatures of oxygen-rich blood. Blood indicates that the brain is doing something, but it’s not a direct measure of brain activity.

Which is to say, there’s room for error. That’s why neuroscientists use special statistics to filter out noise in their fMRIs, verifying that the shaded blobs they see pulsing across their computer screens actually relate to blood flowing through the brain. If those filters don’t work, an fMRI scan is about as useful at detecting neuronal activity as your dad’s “brain sucking alien” hand trick. And a new paper suggests that might actually be the case for thousands of fMRI studies over the past 15 years. [Read more…]

The video captures the active second stage of labour as the mother expels the fetus. The technique, called cinematic MRI, takes repeated images of the same slice of the body before joining them up to create an ultra-detailed video. It was recently turned on unborn twins for the first time to study a common complication where one fetus receives more of the blood supply and becomes much larger than the other.

By using MRI, the team was able to examine the relationship between the movement of the fetus and its position as it travels through the birth canal, which should help doctors better manage labour and delivery. In the future, the team also hopes to visualise the first stage of labour using the same technique, possibly using the videos to create virtual-reality computer training.

In recent years, there has been some provocative evidence that gadolinium, the most widely used contrast agent for MRI studies has a tendency to accumulate in the brain. This fact has been confirmed by multiple major studies but there is still little direct proof of ill effects. We covered this in an article that looked into a Mayo Clinic study. In the article, we promised to bring you news of future studies on the negative effects of gadolinium, if any. Turns out, there have been some interesting insights regarding these concerns, but what has recently burst onto the scene is a new alternative to gadolinium altogether. Scientists have found a way to take advantage of a unique property of cancerous tumors, and now propose a novel contrast agent, D-glucose, more commonly known as dextrose. With this new contrast, healthcare professionals can potentially circumvent gadolinium for investigating brain tumors. [Read more…]