news flash: emotions sometime trump rational thought! Shocking, I know. Though I was intrigued at how the fMRI paradigm in this case provides a neat empirical example for why prisoner’s dilemma models don’t translate well into real-world practice:
A classic economic example is the “ultimatum game,” in which one participant gets 10 $1 bills (or loonies, in Canada). He chooses how many to offer to a second participant. If she accepts the offer, the money is split the way the first participant suggested; if she rejects the offer, nobody gets anything.
Logically, the first participant can maximize his money by offering a single dollar, because logically the second participant should accept that as being better than nothing. In real life, however, the second participant, if offered only a dollar or two, almost always rejects the offer.
Functional MRI scans of brain activity show that a low offer stimulates an area associated with negative emotions, including anger and disgust. It seems the second participant would rather punish the first participant for making such an insulting offer than make an easy buck. And usually, the person making the offer understands this and offers something close to an even split, averaging about $4.
I don’t really see why the above reasonable decision-making process is inherently non-rational or “emotional” though. Doesn’t it make good rational sense to “punish” someone making a lowball offer, so they are motivated to offer you more up front?
Matt McIntosh, writing at Gene Expression, proposes The Lamp Post rule for discussions of science and science policy. Simply stated, “All arguments conducted in a state of relative ignorance must be algebraic.” Head over to GNXP for details.
The Scientist has released the results of its annual poll and the verdict: MD Anderson Cancer Center in Houston ranks highest, followed by the J. David Gladstone Institutes in San Francisco and the Environmental Protection Agency in the Research Triangle Park. Via Ars,
The most important criteria identified in the survey were access to training and experience that will prove useful, followed by access to books and journals, decent medical insurance, equipment, and the quality of the principal investigator. I’m not sure you’d find many postdocs who would disagree with these; if you’re going to spend three years of your life working on a project, then one would hope the skills and techniques learned would stand you in good stead in the future. Access to the scientific literature is vital, and if you’re not getting paid the earth, the ability to see a good doctor if you get sick is nice.
Least important on the list of concerns was the opportunity to advance within the department, followed by administration issues. Again, this is probably due to the way academic careers work, where it’s beneficial to move from one institution to another for different stages of your career, that way maximizing exposure to the broadest range of techniques, methods and approaches to science. Some institutions are also notoriously reticent about promoting their own postdocs into faculty positions.
An editorial in the Journal of Nuclear Medicine (J Nucl Med. 2007 Mar;48(3):331. PMID: 17332606) argues that combination PET/MRI systems are the future and will supplant PET/CT:
In a number of ways, the path to PET/MRI has been reverse of that to PET/CT. The first PET/CT design emerged from industry–academia collaboration and was a prototype for human clinical use that eventually stimulated a commercial response and led to the development of PET/CT for imaging small animals. In contrast, PET/MRI began with the small-animal design and then, over a decade later, the first PET/MRI brain images were acquired on a dedicated prototype system, following an impressive industrial backing that far exceeded that of the early PET/CT developments.
A mere 2 y after the advent of commercial PET/CT, Johannes Czernin from UCLA, at the 2003 annual DGN meeting, commented that “PET/CT is a technical evolution that has led to a medical revolution.” Today, at the dawn of PET/MRI, it may be said that “PET/MRI is a medical evolution based on a technical revolution.” Although PET/CT appears to have replaced stand-alone PET for most oncologic indications, it is reasonable to assume that PET/MRI will be the preferred imaging option for neurologic and central nervous system indications. Without doubt, such dual-modality combinations are here to stay because they incorporate the diagnostic power of PET. Thus, PET/CT and PET/MRI, by virtue of their combined anatometabolic imaging, will lead to a “new-clear” medicine and the demise of “unclear” medicine.
Continue reading “PET and MRI”
The following just came out over the SMRT mailing list:
Vendor issues new warning on Omniscan MR contrast for patients with kidney disease
GE Healthcare warned European providers Feb. 7 to discontinue the use of gadodiamide (Omniscan) for patients who may be at risk for a rare and life-threatening skin disease.
read the rest of the press release below the fold. Continue reading “GE issues warnings about Omniscan”
Medtronic began the evaluation of its EnRhythm® MRI SureScan™ pacer, a technology designed for safe use in MRI machines, “under specified scanning conditions.” The company did not disclose what these specified scanning conditions are.
There’s a copy of the press release, too. I assume that certain kinds of scans are off-limits, like diffusion imaging. Eddy currents are probably the major concern. The press release does mention,
The EnRhythm MRI SureScan pacemaker includes modified hardware to minimize the level of energy transmitted through the lead/device connection point. The pacemaker also includes a new SureScan™ feature that can be programmed “on” before an MRI scan to eliminate the impact of MRI-generated electrical noise, which can prevent necessary pacing therapy or cause the device to oversense and deliver unnecessary pacing therapy. When the SureScan feature is on, the device’s data collection and monitoring functions are temporarily suspended, while allowing the device to continue providing asynchronous pacing if needed.
Imagine the future of this technology… what would be truly cool would be a pacemaker than can be interfaced to the scanner directly, so that pacing can be synchronized with the pulse sequence itself.
2007 may be a big year, at least according to industry spokespeople:
Low-cost MRI machines, super-fast Internet routers, and high-capacity power lines top the list of likely breakthroughs in the field of superconductivity in 2007, according to a ‘Top-10’ forecast list released today by Elie K. Track, Ph.D., senior partner, HYPRES Inc., a leading developer of superconducting microelectronics technology.
Dr. Track compiled the list of expected breakthroughs through comprehensive industry research, conversations with numerous scientific experts around the world, and through his work at HYPRES. The list was developed in an effort to pull together information on the wide variety of superconductivity projects worldwide and begin a dialog about the innovative advancements and breakthrough applications that are well positioned to occur next year.
“In my conversations with many respected colleagues, I continue to hear about new and exciting applications and breakthroughs that are likely to take place in 2007, largely because of the involvement of superconductor-based technologies,” said Dr. Track. “I thought it would be useful to pull all these together into one list so we can truly realize and appreciate the profound impact that superconductivity will have on various industries, the scientific community, and the average person in the coming year.”
Topping the list is an expected breakthrough announcement of laboratory demonstrations that can lead to an advanced, low-cost MRI machine that leverages superconducting technology.
It’s not clear to me how advances in supercon would lead to cheaper MRI machines. If room-temperature superconductors are developed, then design of MR machines can be simplified dramatically of course – no more cryo. But wouldn’t such new technology be expensive as well? I think it’s more likely that breakthroughs would lead to smaller MRI systems, ultimately even the fabled desktop unit. But cost savings aren’t going to come down the pike for years, even if high-temp supercon arrives tomorrow.
Philip Gordon, M.D. is a neonatologist whose blog, Tales from the Womb, occasionally touches on MRI-related topics. He has a recent post about the trouble with MRI in neonatology that is well worth reading. He takes issue with the emerging practice of attempting to use MRI to predict neuro-developmental outcomes in preterm infants, pointing to a paper in NEJM last year as well as a more recent study at UNC Chapel Hill. He is highly skeptical:
Continue reading “MRI of neonates”
from the AP wire: Significant inventors honored Thursday on Capitol Hill
WASHINGTON (AP) — Inventors of the MRI, the Ethernet, the LP record and a popular weedkiller are among 18 people picked for induction into the National Inventors Hall of Fame.
The 2007 class of inductees was to be announced at an event Thursday on Capitol Hill. The honorees are joining luminaries such as Thomas Edison, Velcro inventor George de Mestral and Charles Goodyear, developer of vulcanized rubber.
“Some of these inventors … have literally changed the way we live our lives,” said Rini Paiva, spokeswoman for the National Inventors Hall of Fame Foundation. But, she added, “they are not household names.”
Among the latest inductees and their inventions are:
—Paul C. Lauterbur, for the MRI, or magnetic resonance imaging.
—Robert M. Metcalfe, for high-speed networking known as Ethernet.
—the late Peter C. Goldmark, for the long-playing record.
—John E. Franz, for the herbicide Roundup.
The Akron, Ohio-based hall was founded by the U.S. Patent and Trademark Office and the National Council of Intellectual Property Law Associations. It has inducted members since 1973 and will have honored 331 inventors with the new class.
The ceremony will be in May. More information will be at the National Inventor Hall of Fame website at http://www.invent.org.
That’s “not safe for work”, not “national science foundation” up there in the acronym. It was surely inevitable that this amazing, subtle and elegant technology would eventually be applied to more scatological pursuits. The following paper is a classic in this genre.
Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal.
OBJECTIVE: To find out whether taking images of the male and female genitals during coitus is feasible and to find out whether former and current ideas about the anatomy during sexual intercourse and during female sexual arousal are based on assumptions or on facts. DESIGN: Observational study. SETTING: University hospital in the Netherlands. METHODS: Magnetic resonance imaging was used to study the female sexual response and the male and female genitals during coitus. Thirteen experiments were performed with eight couples and three single women. RESULTS: The images obtained showed that during intercourse in the “missionary position” the penis has the shape of a boomerang and 1/3 of its length consists of the root of the penis. During female sexual arousal without intercourse the uterus was raised and the anterior vaginal wall lengthened. The size of the uterus did not increase during sexual arousal. CONCLUSION: Taking magnetic resonance images of the male and female genitals during coitus is feasible and contributes to understanding of anatomy.
Schultz et al, BMJ. 1999 Dec 18-25;319(7225):1596-600. PMID 10600954.
Continue reading “NSFW MRI: Sex at 1.5T”