magnetic-imaging

sciencealert.com
NASA Might Have Just Solved One of the Sun's Oldest Mysteries
Why the atmosphere is hotter than the surface.
By David Nield

Pictures beamed back from a NASA space observatory are helping to solve a mystery that’s puzzled scientists since the 1940s: why the outer atmosphere of the Sun, its corona, is hotter than the visible surface.

And we’re not talking about a minor temperature discrepancy, either. At the visible surface of the Sun, you can expect a toasty temperature of about 5,500 degrees Celsius (or 9,932 degrees Fahrenheit), but up in the corona, the temperature is around 200 to 500 times hotter.

Now, based on observations from the IRIS (Interface Region Imaging Spectrograph) mission, NASA researchers think the corona is partly heated by ‘heat bombs’ going off, caused by blasts of energy from magnetic fields criss-crossing and realigning in the corona.

Continue Reading.

Learning to Turn Down Your Amygdala Can Modify Your Emotions

Training the brain to treat itself is a promising therapy for traumatic stress. The training uses an auditory or visual signal that corresponds to the activity of a particular brain region, called neurofeedback, which can guide people to regulate their own brain activity.

However, treating stress-related disorders requires accessing the brain’s emotional hub, the amygdala, which is located deep in the brain and difficult to reach with typical neurofeedback methods. This type of activity has typically only been measured using functional magnetic resonance imaging (fMRI), which is costly and poorly accessible, limiting its clinical use.

A study published in the current issue of Biological Psychiatry tested a new imaging method that provided reliable neurofeedback on the level of amygdala activity using electroencephalography (EEG), and allowed people to alter their own emotional responses through self-regulation of its activity.

“The major advancement of this new tool is the ability to use a low-cost and accessible imaging method such as EEG to depict deeply located brain activity,” said both senior author Dr. Talma Hendler of Tel-Aviv University in Israel and The Sagol Brain Center at Tel Aviv Sourasky Medical Center, and first author Jackob Keynan, a PhD student in Hendler’s laboratory, in an email to Biological Psychiatry.

The researchers built upon a new imaging tool they had developed in a previous study that uses EEG to measure changes in amygdala activity, indicated by its “electrical fingerprint”. With the new tool, 42 participants were trained to reduce an auditory feedback corresponding to their amygdala activity using any mental strategies they found effective.

During this neurofeedback task, the participants learned to modulate their own amygdala electrical activity. This also led to improved downregulation of blood-oxygen level dependent signals of the amygdala, an indicator of regional activation measured with fMRI.

In another experiment with 40 participants, the researchers showed that learning to downregulate amygdala activity could actually improve behavioral emotion regulation. They showed this using a behavioral task invoking emotional processing in the amygdala. The findings show that with this new imaging tool, people can modify both the neural processes and behavioral manifestations of their emotions.

“We have long known that there might be ways to tune down the amygdala through biofeedback, meditation, or even the effects of placebos,” said John Krystal, Editor of Biological Psychiatry. “It is an exciting idea that perhaps direct feedback on the level of activity of the amygdala can be used to help people gain control of their emotional responses.”

The participants in the study were healthy, so the tool still needs to be tested in the context of real-life trauma. However, according to the authors, this new method has huge clinical implications.

The approach “holds the promise of reaching anyone anywhere,” said Hendler and Keynan. The mobility and low cost of EEG contribute to its potential for a home-stationed bedside treatment for recent trauma patients or for stress resilience training for people prone to trauma.

Why artificial intelligence has not revolutionised healthcare… yet

by Olivier Salvado

Artificial intelligence and machine learning are predicted to be part of the next industrial revolution and could help business and industry save billions of dollars by the next decade.

The tech giants Google, Facebook, Apple, IBM and others are applying artificial intelligence to all sorts of data.

Machine learning methods are being used in areas such as translating language almost in real time, and even to identify images of cats on the internet.

So why haven’t we seen artificial intelligence used to the same extent in healthcare?

Radiologists still rely on visual inspection of magnetic resonance imaging (MRI) or X-ray scans – although IBM and others are working on this issue – and doctors have no access to AI for guiding and supporting their diagnoses.

Keep reading

The Sun is better than art

This incredible image was produced using data from NASA’s Solar Dynamics Observatory (SDO) taken on January 17, 2003. This is the sun photographed as it was building towards a major eruption.

SDO carries imaging instruments that photograph different wavelengths of light released from the sun. If you remember your physics, there is a relationship between the wavelength of light, the frequency of the light, and the energy of the light, so SDO images basically reflect the temperature of the sun.

The colors in this shot are 3 different wavelengths of light. Temperature across the sun’s surface and in its corona varies as gases are moved around by convection and by the sun’s powerful magnetic field. Images like this are both gorgeous and help scientists understand the forces churning beneath the surface of the body at the heart of the solar system.

-JBB

Image credit: NASA Goddard/SDO

Top 20 with Median annual wage (2012):

20. Electrical power-line installers and repairers: $63,250

19. Transportation inspectors: $63,680

18. Gaming managers: $65,220

17. Magnetic resonance imaging technologists: $65,360

16. Registered nurses: $65,470

15. Diagnostic medical sonographers: $65,860

14. Power plant operators: $66,130

13. Funeral service directors: $66,720

12. Nuclear technicians: $69,069

11. Farmers, ranchers, and other agricultural managers: $69,300

10. First-line supervisors of non-retail sales workers: $70,060

9. Nuclear medicine technologists: $70,180

8. Dental hygienists: $70,210

7. Power distributors and dispatchers: $71,690

6. Commercial pilots: $73,280

5. Detectives and criminal investigators: $74,300

4. Nuclear power reactor operators: $74,990

3. Elevator installers and repairers: $76,650

2. Radiation therapists: $77,560

1. Air traffic controllers: $122,530


Source

So there’s loads of different neuroimaging methods out there that are used depending on what it is you’re looking for! I’ve had the privilege of actually studying it and there’s so so many different types more than just functional MRI that people don’t really know about so here are a few and what they’re used for an how they work.

MRI - Magnetic Resonance Imaging

The most commonly used form of neuroimaging and for good reason. MRI uses the body’s tissue density and magnetic properties of water to visualise structures within the body. It has really incredible spatial and temporal quality and is predominantly used in neuroscience/neurology for looking for any structural abnormalities such as tumours, tissue degeneration etc. It’s fantastic a fantastic form of imaging and is used in numerous amounts of research.

Functional MRI (fMRI)

These images are captured the same way as MRI but the quality is a little bit lower because the aim is to capture function (those blobs you can see) as quickly and accurately as possible so the quality is compromised a little bit. Nonetheless, fMRI usually uses the BOLD response to measure function. It measures the amount of activity in different areas of the brain when doing certain things, so during a memory test for example, and it does that by measuring the amount oxygen that a certain area requires. The increased oxygen is believed to be sent to an area where there is more neuronal activity, so it’s not a direct measurement but rather we’re looking at a byproduct. There are numerous studies trying to find the direct link between the haemodynamic response and neuronal activity, particularly at TUoS (where I’m doing my masters!) but for the moment this is all we have. This sort of imaging is used a lot for research and checking the general function of the brain, so if you were to have had surgery on your brain, they may run one of these just to see which areas might be affected from it and how, or in research we’ve used this a lot to research cognition - which areas are affected during certain cognitive tasks (ie my MSc thesis - Cognition in schizophrenia and consanguinity). 

Diffusion Tensor Imaging (DTI)

This is my current favourite type of NI right now! DTI is beautiful, unique and revolutionary in this day and age, it’s almost like sci-fi stuff! DTI measures the rate of water diffusion along white matter tracts and with that calculates the directions and structural integrity of them to create these gorgeous white matter brain maps. They are FANTASTIC for finding structural damage in white matter - something that is making breakthroughs in research lately ie. schizophrenia, genetics and epilepsy. It measures the rate of diffusion which tells you about possible myelin/axonal damage and anisotropy, so the directions and if they are “tightly wound” or loosely put together - think of it like rope, good FA is a good strong rope, poor FA is when it starts to fray and go off in different directions - like your white matter tracts. My current research used DTI and it was honestly surreal to work with, the images are also acquired through an MRI scanner so you can actually get these images the same time you’re getting MRI’s done, functional or otherwise! 

Positron Emission Tomography (PET)

One of the “controversies” (if you could call it that) is the use of radioactive substances in PET scanning. It requires the injection of a nuclear medicine to have the metabolic processes in your brain light up like Christmas! It uses a similar functional hypothesis to BOLD fMRI, in that it is based on the assumption that higher functional areas would have higher radioactivity and that’s why it lights up in a certain way. It depends on glucose or oxygen metabolism, so high amounts of glucose/oxygen metabolism would show up red and less active areas would show up blue, perfect for showing any functional abnormalities in the overall brain. However it has incredibly poor temporal resolution and due to it’s invasive nature, MRI is chosen more often. (The pictures are gorgeous though!) 

Electroencephalography/Magnetoencephalography (EEG & MEG)

These are not “imaging” types in the stereotypical sense. They create a series of waves that you can physically see (think of the lines you get on a lie detector!). Electrodes/Tiny magnets are placed on the scalp/head in specific areas corresponding to certain brain structures. EEG picks up on electrical activity which is the basis of neuronal function, whereas MEG picks up on magnetic fields - the same property that is utilised by MRI. One of the biggest issues with EEG is that deeper structures passing through tissues get distorted, whereas MEG doesn’t because it only measures the magnetic properties. I’ve not had a lot of experience with either of these but I do know EEG is used in a lot of medical procedures to measure brain activity, from measuring seizures and sleep disorders to measuring brain activity in a coma. It’s fantastic and if you can actually figure out how to conduct and interpret results it’s an invaluable tool into looking at electrical activity. 

Grid of Id

Using a mapping technology called diffusion spectrum magnetic resonance imaging, Harvard University researcher Van Wedeen and colleagues show that the human brain may be wired more like a street map – a grid of pathways – rather than the presumed spaghetti-like tangle of neuronal connections.

The work, part of the Human Connectome Project, shows sheets of parallel neural fibers running at 90 degrees to each other, much like woven fabric, each sheet arranged at right angles to others to form a three-dimensional grid.

The Monstrous Active Galaxy NGC 1275

Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission. NGC 1275 accretes matter as entire galaxies fall into it, ultimately feeding a supermassive black hole at the galaxy’s core.

The reddish structure surrounding the galaxy are filaments.These filaments are cool despite being surrounded by gas that is around 55 million degrees Celsius hot. They are suspended in a magnetic field which maintains their structure and demonstrates how energy from the central black hole is transferred to the surrounding gas.

Credit: NASA, ESA and Andy Fabian (University of Cambridge, UK)

2

BURMESE PYTHON EATS RAT
BURMESE PYTHON DIGESTS RAT
Noninvasive Imaging Technology Shows Animal Guts

Science is inherently cool, but gross science is even better.

Using a combination of computer tomography (CT) and magnetic resonance imaging (MRI), scientists Kasper Hansen and Henrik Lauridsen of Aarhus University in Denmark were able to visualize the entire internal organ structures and vascular systems (aka “guts”) of a Burmese Python digesting a rat.

  • A Burmese Python was scanned before ingesting a rat
  • and then at 2, 16, 24, 32, 48, 72 and 132 hours afterwards.
  • The succession of images reveals
    a gradual disappearance of the rat’s body,
  • with an overall expansion of the snake’s intestine,
  • shrinking of the gallbladder
  • and a 25 percent increase in heart volume.

(via Asylum.com)

While no pythons were harmed in making this series of images,
the same cannot be said about rats. We might take a moment to think about how rats have made great sacrifices to bring our understanding of the biological sciences to where it is today.

This is a huge whoops!

A bug in fMRI software could invalidate 15 years of brain research

There could be a very serious problem with the past 15 years of research into human brain activity, with a new study suggesting that a bug in fMRI software could invalidate the results of some 40,000 papers.

That’s massive, because functional magnetic resonance imaging (fMRI) is one of the best tools we have to measure brain activity, and if it’s flawed, it means all those conclusions about what our brains look like during things like exercise, gaming, love, and drug addiction are wrong.

“Despite the popularity of fMRI as a tool for studying brain function, the statistical methods used have rarely been validated using real data,” researchers led by Anders Eklund from Linköping University in Sweden assert.

4

The quest to build a digital public library of brains

At the Brain Observatory, Dr. Jacopo Annese and his team painstakingly cut brains into thousands of thin slices. Those delicate tissues are then digitally archived as images that will be accessible to anyone with Internet.

Among the archived is the brain of one of the world’s most famous and most studied amnesiac patients, Henry Molaison—more commonly known as “H.M.”

In 2009, Annese dissected H.M.’s postmortem brain and used the anatomical images to create a digital 3-D model. During the process, he also found a lesion in H.M.’s cortex that was previously undiscovered, revealing new insight into how memory works.

The lab’s mission is to document the detailed, cellular view of the brain that can’t be captured by current magnetic resonance imaging (MRI) technology. And having an open access library enables crowdsourcing and increases the likelihood that someone could potentially uncover something important.

As the library grows, the collection of images will also serve as a high-resolution guide for doctors and researchers to better understand what exactly might be happening in the brain tissues of patients with the same neurological conditions.

Annese founded the lab in 2004 while he was a professor of radiology at UC San Diego. The lab’s operation later moved under the roof of the Institute for Brain and Society, the nonprofit he founded in 2013.

GIF source: Ars Technica

The Dance Magnetic

Magnetic field lines on the Sun sprout from active regions on the solar surface, arcing upwards before reconnecting back to an area with the opposite polarity. Solar material is suspended along these soaring structures, creating the coronal loops seen in so many images of the Sun.

In this image from NASA’s Solar Dynamics Observatory (SDO), the coronal loops are shown in white. Their arcing traces were captured with the Atmospheric Imaging Assembly (AIA). That data was overlaid on information obtained using SDO’s Helioseismic Magnetic Imager (HMI), which shows magnetic fields on the solar surface in false color. The composite image illustrates the swirling magnetic dance playing out on our star.

Captured on 24 October 2014, this image was chosen as one of the favorites of the SDO staff out of the first 100 million shots taken with the AIA.

-JF

Image credit: NASA/SDO/HMI/AIA/LMSAL

Source