magnetic-imaging

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


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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)

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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.

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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

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In green company: aurora over Norway

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds – mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display. Arms went high in the air, patience and experience paid off, and the amazing featured image was captured. The setting is a summit of the Austnesfjorden fjord close to the town of Svolvear on the Lofoten islands in northern Norway. The time was early March. Our Sun has been producing an abundance of picturesque aurora of late as it is near the time of its maximum surface activity in its 11-year magnetic cycle.

Image credit & copyright: Max Rive

Brain scans link concern for justice with reason, not emotion

People who care about justice are swayed more by reason than emotion, according to new brain scan research from the Department of Psychology and Center for Cognitive and Social Neuroscience.

Psychologists have found that some individuals react more strongly than others to situations that invoke a sense of justice—for example, seeing a person being treated unfairly or mercifully. The new study used brain scans to analyze the thought processes of people with high “justice sensitivity.”

“We were interested to examine how individual differences about justice and fairness are represented in the brain to better understand the contribution of emotion and cognition in moral judgment,” explained lead author Jean Decety, the Irving B. Harris Professor of Psychology and Psychiatry.    

Using a functional magnetic resonance imaging (fMRI) brain-scanning device, the team studied what happened in the participants’ brains as they judged videos depicting behavior that was morally good or bad. For example, they saw a person put money in a beggar’s cup or kick the beggar’s cup away. The participants were asked to rate on a scale how much they would blame or praise the actor seen in the video. People in the study also completed questionnaires that assessed cognitive and emotional empathy, as well as their justice sensitivity.

As expected, study participants who scored high on the justice sensitivity questionnaire assigned significantly more blame when they were evaluating scenes of harm, Decety said. They also registered more praise for scenes showing a person helping another individual.

But the brain imaging also yielded surprises. During the behavior-evaluation exercise, people with high justice sensitivity showed more activity than average participants in parts of the brain associated with higher-order cognition. Brain areas commonly linked with emotional processing were not affected.

The conclusion was clear, Decety said: “Individuals who are sensitive to justice and fairness do not seem to be emotionally driven. Rather, they are cognitively driven.” 

According to Decety, one implication is that the search for justice and the moral missions of human rights organizations and others do not come primarily from sentimental motivations, as they are often portrayed. Instead, that drive may have more to do with sophisticated analysis and mental calculation.

Decety adds that evaluating good actions elicited relatively high activity in the region of the brain involved in decision-making, motivation and rewards. This finding suggests that perhaps individuals make judgments about behavior based on how they process the reward value of good actions as compared to bad actions.

“Our results provide some of the first evidence for the role of justice sensitivity in enhancing neural processing of moral information in specific components of the brain network involved in moral judgment,” Decety said.

huffingtonpost.com
Neuroscience finds a distinction between birth-assigned sex and gender identity

Researchers from the Medical University of Vienna have discovered there may be a neurological distinction between a person’s birth-assigned sex and their gender identity, according to a new study. 

Here’s a recap of what they found:

Led by Georg S. Kanz of the University Clinic for Psychiatry and Psychotherapy, the study was composed of 23 trans men, 21 trans women, 23 cis women and 22 cis men. Researchers used a type of MRI (“diffusion-weighted magnetic resonance imaging” is the proper term, should you ever want to sound impressive during a dinner party) to measure diffusion of particles across brain matter. Cis women had the highest diffusivity – which means (bear with me here) that particle movement in white matter brain regions was greatest for this group, followed by trans men. Trans women had lower movement than the former, with cis men having the least.

There is some early evidence, then, that science is catching up with something many of us already assume, and for good reason: Gender identity exists on a scale, rather than in narrow dichotomized groups. In essence, trans people had brain chemistry approaching the middle of the gender spectrum – inherently different from their biological sex and closer to their identified gender. For example, a trans woman has significantly different brain movement than a cis man, despite having the same biological sex. Moreover, trans men and trans women were different from each other, implying that the brain shows a wide range of gender based differences, rather than simply male or female.

Previous studies have had similar results, but it’s too early to jump to a huge conclusion that changes the entire way we view a trans person’s biology and experiences; factors like hormone therapy, for example, can affect the results.

But what we can say is that we may have “some brain-based evidence to support that gender indeed exists on a spectrum,” as the writer puts it, and that the issues trans people face simply for being themselves are taken more seriously every day. 

Effects of Anesthesia on the Fetal Brain

Exposure to anesthesia during labor and delivery results in morphological changes in the developing fetal brain. Photo credit: Bradley Peterson, MD, Institute of the Developing Mind, Children’s Hospital Los Angeles.

Recently recommended in F1000Prime, which identifies significant studies in biology and medicine based on recommendations from leadings scientists around the world, a study by researchers led by Bradley Peterson, MD of CHLA demonstrated significant effects of anesthesia used during labor and delivery on the developing fetal brain. Using high-resolution magnetic resonance imaging (MRI), Peterson and his team found infants exposed to anesthesia had areas in the frontal and occipital lobes of the brain that were larger in size compared to those who had not been exposed. The size of these areas of the brain increased with longer durations of anesthetic exposure. The effects of these differences in morphology based on anesthesia exposure are yet to be determined.