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Imaging, Public Safety

MRI use flushes gadolinium into San Francisco Bay

MRI use flushes gadolinium into San Francisco Bay

22951789105_b548e1e5d6_o_Flickr_ScienceActivismThe levels of gadolinium in the San Francisco Bay have been steadily increasing over the past two decades, according to a study recently published in Environmental Science & Technology. Gadolinium is a rare-earth metal and the potential long-term effects of its environmental exposure have not been studied in detail.

Russell Flegal, PhD, and his research team at UC Santa Cruz collected and analyzed water samples throughout the San Francisco Bay from 1993 to 2013, as part of the San Francisco Bay Regional Monitoring Program.

They found the gadolinium levels to be much higher in the southern end of the Bay, which is home to about 5 million people and densely populated with medical and industrial facilities, than in the central and northern regions. They also observed a sevenfold rise in gadolinium concentration in the South Bay over that time period.

The study attributes the rising level of gadolinium contamination largely to the growing number of magnetic resonance imaging (MRI) scans performed with a gadolinium contrast agent. A gadolinium contrast agent is used for about 30 percent of MRI scans to improve the clarity of the images. It is injected into the patient and then excreted out of the body in urine within 24 hours.

Lewis Shin, MD, assistant professor of radiology and a MRI radiologist, explained to me the importance of using intravenous gadolinium contrast agents:

Gadolinium contrast agents allow us to detect abnormalities that would otherwise be hidden from view and to improve our characterization of the abnormalities that we do find. Gadolinium is not always used; for example, if a physician is just concerned about identifying a herniated disk in the spine, an MRI without contrast agent is sufficient.

However, gadolinium is routinely administered to detect and characterize lesions if there is a clinical concern of cancer. Also, if a patient was previously treated for cancer, gadolinium administration is often extremely helpful to detect early recurrences. MRI with a gadolinium contrast agent greatly improves our ability to make an accurate diagnosis not only for cancer but for many other disease processes as well.

According to the UCSC researchers, gadolinium is not removed by standard wastewater treatment technologies, so it is discharged by wastewater treatment plants into surface waters that reach the Bay.

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Cancer, Imaging, In the News, Medicine and Society, Women's Health

This breast cancer is mine: When doctors get sick

This breast cancer is mine: When doctors get sick

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As the death last year of neurosurgeon Paul Kalanithi, MD, reminded us all, successful physicians aren’t protected from the onslaught of medical maladies that can strike anyone at any time.

Take Kimberly Allison, MD, a breast cancer researcher whose personal experience with the disease is featured in a recent Newsweek article and whose own breast cancer cells are shown above.

In 2008, Allison found a “shelf-like formation” under her arm. Only 33, she calls the experience “completely disorienting.” One minute she’s a doctor. The next, a patient.

As a pathologist, she was equipped to examine her own cells, as described in the article:

Slow-growing cancers appear almost like normal cells under a microscope’s lens. But then, Allison says, there are “big, bad and ugly” aggressive cancers. Instead of being neatly arranged into structures, these cancer cells swell and lose their tidy alignment. That’s what Allison saw when she peered through the microscope at her own cells.

This story has a happy ending. Allison penned a book on her experience, and she is now advancing the science on the particular type of breast cancer that struck her.

For more on Allison’s experience, check out this 1:2:1 podcast with Allison and Paul Costello, chief communications officer at the School of Medicine.

Previously: “You have cancer”: On being a doctor and receiving the news, Stanford neurosurgeon/cancer patient Paul Kalanithi: “I can’t go on. I will go.” and Stanford neurosurgeon Paul Kalanithi, who touched countless lives with his writing, dies at 37
Image courtesy of Kimberly Allison

Cancer, Imaging, Women's Health

Education reduces anxiety about mammography

Education reduces anxiety about mammography

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My close childhood friend Kelly died from breast cancer when she was only 32 years old. This inspired me to choose a research position at Berkeley Lab to help develop new breast-imaging scanners to improve early detection. Given my expertise in this field, my friends come to me with their confusion and ask, “At what age and how frequently should I get a mammogram?”

There has been a lot of debate surrounding mammography screening since 2009 when the United States Preventive Services Task Force revised the guidelines for average-risked women, limiting routine screening to biennial mammography for women 50 to 74 years of age.

The researchers recommended increasing the screening age in part because of the harmful anxiety caused by false-positive results, which are more common in younger women. The American Cancer Society recently released a new set of guidelines that recommends yearly mammograms starting at age 45, but they also considered the pain, anxiety and other potential side effects of mammography.

A recent article published in the Journal of the American College of Radiology describes a successful intervention to reduce this anxiety. The authors organized interactive one-hour educational sessions on mammography, which were led by a trained breast radiologist.

Before the lecture, a questionnaire was administered to the participants to identify their anxiety and previous mammography experience — 117 responded. Those respondents who reported having anxiety about mammography screening indicated “unknown results” and “anticipation of pain” as the primary sources of their anxiety.

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Imaging, Research, Science, Stanford News, Surgery

A dye to try: New compound provides improved imaging, safety

A dye to try: New compound provides improved imaging, safety

The NIR-II dye can clearly resolve blood vessels in the hindlimb as well as in the brain with unprecedented clarity. Furthermore, the dye allows clear resolution of tumors in the center of the mouse’s brain and is capable of ultra-sensitive tumor detection.

A team of Stanford-led researchers has created a dye capable of identifying tumors in a variety of tissues and providing surgeons with real-time video feedback during surgery.

And the best part of this molecular fluorescent dye? It’s much safer for humans than many other existing dyes because it can be excreted through urine within 24 hours, the researchers say.

They explain in a recent Stanford News article:

“The difficulty is how to make a dye that is both fluorescent in the infrared and water soluble,” said Alex Antaris, a chemistry graduate student and the first author on a recent paper in the journal Nature Materials. “A lot of dyes can glow but are not dissolvable in water, so we can’t have them flowing in human blood. Making a dye that is both is really the difficulty. We struggled for about three years or so and finally we succeeded.”

The new dye also provides more detailed images than were previously available, making it helpful for diagnostics or for guiding surgery, Antaris said.

The paper’s senior authors are Hongjie Dai, PhD, professor of chemistry, and Zhen Cheng, PhD, associate professor of radiology, and Xuechan Hong, PhD, of Wuhan University, China.

Previously: Better tumor-imaging contrast agent: the surgical equivalent of “cut along dotted line”?, Stanford instructor called out for his innovative — and beautiful — imaging work and New molecular imaging could improve bladder-cancer detection  
Image by Alexander Antaris

Bioengineering, Imaging, Neuroscience, Research, Stanford News

Brain radio: Switching nerve circuit’s firing frequency radically alters alertness levels in animal models

Brain radio: Switching nerve circuit's firing frequency radically alters alertness levels in animal models

brain radioIt’s a kick to consider that a part of the brain could act like a radio, with different stations operating at different frequencies, playing different kinds of music and variously attracting or repelling different “listening audiences.” A new study by Stanford neuroscientist Jin Hyung Lee, PhD, and her colleagues has isolated a brain circuit linking just such a “transmission station” in the midbrain to various “listener” regions in the forebrain.

The findings have clear therapeutic potential. In a news release about the research, I wrote:

In a case study published in 2007, [researchers] demonstrated that electrically stimulating the central portion of the thalamus — a deep-brain relay station routing inputs from the senses to myriad cognitive-processing centers throughout the cerebral cortex — could restore consciousness in a patient who’d been in a minimally conscious state for six years.

“But there was no way to know how it worked,” Lee told me.

Now, in a set of experiments published in eLife, she and her associates have used precisely targeted stimulation and recording techniques to show that forcing a set of nerve cells in the central thalamus to fire at 40 or 100 times a minute induces a state of arousal: Rats that were fast asleep wake up and start roving around and exploring their environments. Switch the same nerve cells to a firing frequency of 10 times a minute, and the same rats immediately go into a state of deep unconsciousness more akin to a coma or a petit mal seizure (a transient state of behavioral arrest) than to restful sleep.

In addition to these behavioral effects, forcing those central-thalamic nerve cells to fire at different rates causes distinct structures elsewhere in the brain to rev up or slack off. In a sense, firing at 100 times a minute was like blasting heavy-metal music – some forebrain regions leapt into the mosh pit, some ran for cover – while 10 times a minute (the easy-listenin’ channel?) variously appealed to or turned off different brain areas.

You can’t do that with a drug.

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Imaging, Stanford News

An Egyptian mummy’s visit to Stanford, in pictures

An Egyptian mummy's visit to Stanford, in pictures

Earlier this week we introduced you to a very special guest who came to Stanford. Above are photos from when Hatason, a 3,200-year-old Egyptian mummy, stopped by for a CT scan.

More photos of Stanford Medicine events, (non-mummy) people and places can be found on Instagram.

Previously: Stanford radiologists scan Egyptian mummy for clues to its origin and 3,200-year-old woman comes to Stanford
Photos by Norbert von der Groeben

Imaging, Stanford News, Videos

Stanford radiologists scan Egyptian mummy for clues to its origin

Stanford radiologists scan Egyptian mummy for clues to its origin

A closer look now at the scanning of an Egyptian mummy here. “Mummies of this period are not very plentiful, so each time we have an incremental change in the technology we learn much more and are able to say much more than in the past,” comments Jonathan Elias, PhD, director of the Akhmim Mummy Studies Consortium, in the video.

Previously: 3,200-year-old woman comes to Stanford

Imaging, Stanford News

3,200-year-old woman comes to Stanford

3,200-year-old woman comes to Stanford

Cameras clicked and media people cut in front of one another other with iPhones, trying to get a good shot, as a very old woman arrived at Stanford last week for a CT scan. She wasn’t here for treatment, though. She’s a mummy who has been dead for more than 3,000 years. No one knows her name, but she’s sometimes been called Hatason.

Born in the Egyptian city of Asyut some 3,200 years ago, Hatason lived about 50 years after the great pharaoh Ramesses II. Her home is at the Legion of Honor museum in San Francisco on the bluffs overlooking the Golden Gate Bridge. Eighteen people, not counting Hatason, crammed into a basement research lab near Stanford Hospital to find out what lay inside the ancient wrappings that once enclosed Hatason’s body. (The lab, which features a high-end CT scanner, is managed by Kerstin Müller, PhD, an instructor of radiology at the medical school.) As I wrote for Inside Stanford Medicine:

Was she the same age as the coffin she has been stored in? Or could it have been from an earlier or later period? As the scanner’s long arms whirred and spun around the mummy, the room full of radiology and mummy experts stared intently at the images coming up on several computer displays for clues about who she was. The shape of her skull and hips could reveal her sex, and the way she was wrapped and the presence of amulets might say something about her status.

But the state-of-the-art scanning equipment showed there wasn’t much left but empty space where Hatason’s body once lay; just a scramble of disarticulated bones (see video above).

Amazingly, though, the mummy experts could tell a lot even from that. Her delicate, gracile skull suggested she was a woman and even the peculiar preservation said something about the funerary practices of the Asyut.

We’ll have more videos and photos of Hatason here soon. And stay tuned for more updates after a team of radiology, mummy and Egyptology experts draw their conclusions later this month.

Previously: How Stanford scanned a 2,500-year-old mummyAncient mummy meets modern medicine (and daddy, too) at Legion of HonorMummyblogging, round two and Photoblogging: mummy edition
Video by Lior Molvin of Stanford Radiology, courtesy of the Fine Arts Museums of San Francisco

Cancer, Imaging, Research

Researchers develop molecular target for brain cancer

Researchers develop molecular target for brain cancer

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About 23,000 new cases of brain and central nervous system tumors are diagnosed annually, and more than 15,000 patients are expected to die of brain cancer this year in the United States, according to the American Cancer Society. Glioblastoma multiforme is the most common brain malignancy, but it remains incurable with only 5 percent of patients surviving at least 5 years after diagnosis. This bleak scenario has motivated the search for a better molecular target for glioblastoma multiforme diagnosis and therapy.

Weibo Cai, PhD, an associate professor of radiology and medical physics, and his research team at the University of Wisconsin-Madison searched the Cancer Genome Atlas database and identified an effective biomarker for the deadly glioblastoma multiforme: the CD146 gene, which is highly active in glioblastoma.

CD146 genes place unique CD146 proteins on the surface of cells. Cai’s team developed an antibody that selectively latches onto the CD146 proteins concentrated on the glioblastoma tumors. They also tagged the antibody with a radioactive copper isotope, so the tumors could be easily identified and localized with a positron emission tomograph (PET), an imaging scanner commonly used to detect cancer.

Cai tested their antibody by implanting animal models with human glioblastoma tumors, injecting them with the antibody and imaging them with a small animal PET scanner. The copper-labeled antibody preferentially accumulated in the tumors, allowing PET imaging to accurately identify tumors as small as 2 mm. Their study results were recently reported in the Proceedings of the National Academy of Sciences.

As Cai explained in a university news release:

We’ve created a tag that – at least in our mouse model – is highly specific for this aggressive brain cancer. If the technique proves out in further tests, it could be used to diagnose some strains of aggressive glioblastoma, and also to evaluate treatment progress or even to test potential drugs.

The researchers also found high activity of CD146 in ovarian, liver, and lung tumors so their antibody could have a wide range of applications. However, there is a lot of research to be done before the technique could be used in the clinic. Cai said in the news release, “This targets tumors with the worst survival, but I want to emphasize that human trials are some years in the future.”

Jennifer Huber, PhD, is a science writer with extensive technical communications experience as an academic research scientist, freelance science journalist, and writing instructor.

Previously: You know it when you see it: a precision health approach to diagnosing brain cancerA Stanford neurosurgeon discusses advances in treating brain tumors, and A century of brain imaging
Images by Weibo Cai/Department of Radiology, University of Wisconsin-Madison. On the left, the antibody is linked to a label that shows up in a PET scanner, and the aggressive cancer shines brightly. On the right, a similar cancer without the molecular marker is less obvious.

Bioengineering, Cancer, Imaging, Public Safety, Research, Stanford News, Technology

A new way to scan for plastic explosives could someday detect cancerous tumors

A new way to scan for plastic explosives could someday detect cancerous tumors

14591799636_128fbe50ee_zSci-fi shows and superhero films are full of gadgets and beings that have the power to remotely scan their environment for hidden things. For us mere mortals this superability may sound unachievable, but now Stanford engineers are working to develop a safe and portable way to detect concealed objects by scanning with microwaves and ultrasound.

As this Stanford Report story explains, the idea began with a challenge posed by the Defense Advanced Research Projects Agency: Design a way to detect buried plastic explosives from a safe distance without touching the surface of the ground.

A team of electrical engineers led by assistant professor Amin Arbabian, PhD, and research professor Pierre Khuri-Yakub, PhD, took up the challenge, paying homage to the scanning device made popular by sci-fi show Star Trek in the process. They created a tricorder-like device that senses the ultrasonic waves created by objects as they expand and contract when warmed by electromagnetic energy (e.g., light and microwaves).

Here’s the really interesting part: Because everything expands and contracts when heated — but not at identical rates — this scanning tool could have medical applications as well. For example, blood vessels that sprout from cancerous tumors absorb heat differently than surrounding tissue. So, blood vessels radiating from tumors could appear as “ultrasound hotspots” when scanned with the tricorder device.

The team is working to make this device ready to detect the presence of tumors and other health anomalies sometime within the next decade or so.

Previously: Beam me up! Detecting disease with non-invasive technology and Tiny size, big impact: Ultrasound powers miniature medical implant
Photo by Joe Haupt

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