The CyberKnife normally targets tumors. It uses real-time imaging and a robotic arm to deliver precisely targeted, highly concentrated beams of radiation.

In this study, the researchers aimed at the trigeminal nerve, a three-branched nerve that carries sensations from the face to the brain. Trigeminal neuralgia, which causes electric shock–like facial pain and spasms, affects up to five in 100,000 people. The condition generally strikes in middle age. Pain episodes are usually brief, but they can be so severe that they can trigger depression.

Standard treatments include drugs and surgery. Radiation therapy has been tried, according to the study authors, but it has left up to half of patients with facial numbness.

A team of radiologists, radiation oncologists, and a neurosurgeon at Winthrop-University Hospital in Mineola, New York (on Long Island), tried the CyberKnife on 17 patients whose trigeminal neuralgia hadn’t responded to medication or previous surgery. The doctors used the beam to irradiate a 6-millimeter section of the trigeminal nerve.

Follow-up data were available for 16 of the patients. Of those, 14 experienced either partial or complete pain relief. Eleven reported freedom from all pain at some point following the surgery, and seven of those remained pain-free through their last follow-up visit, which took place an average of five months after surgery.

More research on larger patient cohorts is obviously needed. But, the study concludes:

Non-isocentric radiosurgery can be used as an alternative to more invasive treatments and warrants further follow-up and investigation.

Neuralgia symptoms did recur in four patients, at about three, eight, nine, and 18 months after surgery. Only two patients reported side effects: a “feathery dysesthesia” (pain resulting from a normal stimulus) and a mild loss of sensation in the surgical area.

Related seminar: Neuro & Musculoskeletal Imaging

So says a study by researchers at Henry Ford Hospital in Detroit. They presented it this week at The Triological Society’s annual Combined Sections Meeting in Miami Beach, Florida.

The study retrospectively reviewed the cases of 1,681 patients with dizziness or vertigo who visited a Detroit metropolitan emergency department during the period of January 2008 through January 2011. Of those, 810 received a CT scan of the brain and head, at a total cost over the three years of $988,200. Only 0.74 percent of the scans found anything that required intervention, such as intracranial bleeding or stroke.

Study author Syed F. Ahsan, MD, said:

It is our hope that our investigation into our own practices will shed light on avenues to run leaner practices within our institution, as well as serve as a model for other health systems.

Dr. Ahsan is a neuro-otologist at Henry Ford Hospital, so it seems obvious which “Detroit metropolitan emergency department” the researchers might have studied. He was quoted in a hospital news release.

The problem with CT use in those circumstances is that while intracranial bleeding or stroke may cause dizziness, lots of other causes are more likely. The news release cites dehydration, anemia, drop in blood pressure when standing (orthostatic hypotension), inner-ear problems, and vestibular neuritis.

Dr. Ahsan also noted that previous studies have shown that CT scans don’t do a very good job of detecting stroke or intracranial bleeding in an emergency department setting anyway.

“When a patient comes into the emergency department experiencing dizziness,” he said, “a physician’s first line of defense is often to order a CT scan to rule out more serious medical conditions. But in our experience it is extremely rare that brain and head imaging yields significant results.”

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Two Florida bills would force imaging clinics and other medical offices to post their prices; see our Facebook post.

Related seminar: Emergency Radiology

That could be very useful because the earlier the intervention, the better the prognosis in treating developmental dyslexia.

Senior investigator Nadine Gaab, PhD, of the hospital’s Labs of Cognitive Neuroscience said dyslexia usually isn’t diagnosed until the child is in third grade, although the various available neuropsychological interventions are more effective when begun earlier. The delay in diagnosis, she said, can lead to frustration for both the child, who struggles with reading, and the parents:

Families often know that their child has dyslexia as early as kindergarten, but they can’t get interventions at their schools. If we can show that we can identify these kids early, schools may be encouraged to develop programs.

Dr.Gaab was quoted in a hospital news release. The research is detailed in a study published online this week in Proceedings of the National Academy of Science.

The researchers used functional MRI to scan the brains of preschool-age children—average age: 5½—as the kids performed tasks requiring them to decide whether two words started with the same sound. (For this and other brain research, the researchers have developed an elaborate protocol to get children to hold still in the MRI machine by turning the procedure into a game.)

Children with a family history of developmental dyslexia showed the same brain activity as that exhibited by older children and adults with dyslexia. Children in the control group did not.

Nora Maria Raschle, PhD, also of The Labs of Cognitive Neuroscience, is the study’s lead author. She said the research could make a real difference in the lives of children with dyslexia by allowing them to get early treatment:

We hope that identifying children at risk for dyslexia around preschool or even earlier may help reduce the negative social and psychological consequences these kids often face.

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For another novel use of MRI—examining the feet of sprinters to find out what makes them so fast—see our Facebook page.

Related seminar: Pediatric Radiology—Clinical and Radiology Perspectives

“Currently no standard approach to the evaluation of peripheral neuropathy exists,” said Brian Callaghan, MD, assistant professor of neurology at the University of Michigan Medical School. “We need more research to determine an optimal approach. We do a lot of tests that cost a lot of money, and there’s no agreement on what we’re doing.”

Dr. Callaghan led the research. He was quoted in a University of Michigan Health System news release.

The study was published Monday in Archives of Internal Medicine. It examined the use of 15 “relevant” tests in diagnosing the disorder. The closest thing to a standard approach right now is an MRI of the brain or spine, which was used for 23.2 percent of the patients studied.

Unfortunately, the researchers think that’s a bad idea. They’d prefer a glucose tolerance test, which was used for only 1 percent of the patients. Here’s how the study puts it:

Almost one-quarter of patients receiving neuropathy diagnoses undergo high-cost, low-yield magnetic resonance imaging, whereas few receive low-cost, high-yield glucose tolerance tests.

The most common cause of the nerve dysfunction that characterizes peripheral neuropathy is diabetes. Hence the efficacy of a glucose tolerance test.

Of course, there can be a lot of other causes too, some of which MRI does detect well. However, expect health care’s cost-cutting forces to target its use, at least as a first option. As Dr. Callaghan put it: “Our findings, that MRIs were frequently ordered by physicians but a lower-cost glucose tolerance test was rarely ordered, show that there is substantial opportunity to improve efficiency in the evaluation of peripheral neuropathy.”

Related seminar: Diagnostic Imaging Review: For Residents, Fellows and Radiologists

Breast-cancer researcher Mina Bissell, PhD, explained:

Our data show that at lower doses of ionizing radiation, DNA repair mechanisms work better than at higher doses. This nonlinear DNA damage response casts doubt on the general assumption that any amount of ionizing radiation is harmful and additive.

Dr. Bissell, who holds the title of distinguished scientist at the Berkeley Lab’s Life Sciences Division, was quoted in a lab news release. The findings have particular significance for those who undergo such low-dose medical imaging procedures as mammograms.

The lab revealed the results of its research in a freely available study published online Monday in Proceedings of the National Academy of Sciences.

The decreased risk at low doses derives not from the amount of damage caused by the radiation but rather from how the body fixes the damage. The researchers found that after low doses of radiation, the body repairs double-strand DNA breaks (meaning the double helix is completely severed) on site. It’s a relatively simple procedure with relatively little chance of error.

But as doses increase, creating more double-strand breaks, the broken strands congregate at “radiation-induced foci” (RIF), which are aggregations of repair proteins. With lots of repairs going on at once, the opportunities for mistakes increase.

“We hypothesize that, contrary to what has long been thought, double-strand breaks are not static entities but will rapidly cluster into preferred regions of the nucleus we call DNA repair centers as radiation exposure increases,” said Sylvain Costes, PhD, a biophysicist who led the study.

“As a result of this clustering,” Dr. Costes said, “a single RIF may reflect a center where multiple double-strand breaks are rejoined. Such multiple repair activity increases the risks of broken DNA strands being incorrectly rejoined, and that can lead to cancer.”

The researchers are looking into whether their results, achieved with a single human breast cell line, will hold up with different lines and different breast cells. Stay tuned.

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MRI powers a tiny wireless camera that navigates the digestive system. Science fiction? Find out on our Facebook page.

Related seminar: ALARA — CT (As Low As Reasonably Achievable)

DOTmed News’ Brendon Nofziger quizzed Dr. Sorensen at last week’s Radiological Society of North America annual meeting in Chicago. The interview is worth a read.

Dr. Sorensen said he thought 7-T would soon find the breakthrough application that would push it into the imaging mainstream. Specifically, “I think neuroscience will be the place.”

He’s a neuroradiologist, so you might expect him to say that. But, acknowledging that the powerful machines haven’t yet found a dazzling clinical application, he added, “However, we’re poised to do that in a couple of diseases.”

As for justifying the machines’ cost, he gave this example: “When you look at the cost of treating multiple sclerosis, the therapies are very expensive. And so even an expensive imaging test that can guide that treatment would be very valuable and could easily justify a high cost for its utilization.”

Screening for Alzheimer’s disease might be another opportunity, Dr. Sorensen said:

The early data in some of the trials suggest that some patients actually are getting their memory back. I mean, it’s remarkable, some of the drugs that are in testing. So I think there actually will be a therapy for Alzheimer’s disease in the not-too-distant future.

He’s not that excited about such potential new modalities as magnetic particle imaging (“when you have to put particles into people, that already puts you into a different regime”) or optical imaging (its chief appeal is low cost, “and that’s hard to get excited about when the cost of other tools keeps going down”).

Instead, he touts still-untapped potential in familiar modes. “If you look at what CT scanners do today versus what they did 10 years ago,” Dr. Sorensen said, “it’s a completely different thing. I would say the same about routine MRI. … Is there another technology like MRI or CT out there that’s going to have such an impact? I don’t see one right now.

“We’re certainly watching, looking for it. But I don’t see anything like that in the future.”

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Have a great weekend, but first, please check today’s Facebook post.

Related seminar: Computed Body Tomography: The Cutting Edge

At least we think the food was free. The journal article calls it “complementary,” which means “serving to fill out or complete.” Presumably, the word the authors intended to use was “complimentary.”

Researchers at Mayo Clinic—yes, Mayo Clinic—in Rochester, Minnesota, retrospectively studied meeting attendance for one year with free food provided and for another year after the food service was canceled in a cost-cutting effort. Except for two early-morning meetings at which breakfast was served, all meetings took place over the lunch hour. The researchers followed seven different meeting groups: four in the neuroradiology division and three covering the entire department.

In 2008, the last year of the free food era, average annual attendance for the seven meeting groups ranged from 31 percent to 72 percent. In 2009, during the new starvation regime, attendance ranged from 33 percent to 68 percent.

Concluded Robert J. McDonald, MD, PhD, but not RD (registered dietitian), of the radiology department, and his colleagues:

Our results demonstrated that faculty attendance at monthly meetings in academic radiology was not affected by the presence or absence of complementary [sic] food provisions. These findings applied to both general and divisional meetings as well as working meetings focused on specific departmental tasks.

Mayo saved $92,205 by cutting out the catering. The researchers didn’t mention whether the meeting attendees lost any weight during the no-food year. Perhaps we can look forward to a follow-up study.

Think we’re joking? This study was itself a follow-up to a study published on July 12, 2007, in the open-access journal BMC Medical Education. The earlier article concluded that the addition of free food (paid for by pharmaceutical companies) increased attendance at medical grand rounds.

Dr. McDonald and the other authors of the new study attributed the differing results to faculty members being more interested and invested in their departmental meetings.

Apparently not interested enough in some of them to achieve attendance rates of more than 33 percent, but OK, whatever.

Hmmmm. McDonald … McDonald’s … you don’t suppose … ?

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We wish everyone happy, safe, and well-attended Thanksgiving festivities.

Related seminar: Radiology Review

It comes from the Medical Imaging & Technology Alliance (MITA), a trade group for makers of medical imaging equipment. So perhaps it’s not so surprising.

MITA said in a Wednesday news release that, according to its own analysis of Medicare data, spending on imaging for each Medicare beneficiary has decreased 13.2 percent since 2006. In addition, the release said, imaging utilization per beneficiary decreased by 3 percent in 2010. Spending for Medicare services other than imaging has increased by 20 percent since 2006, and overall utilization increased by 2 percent in 2010, MITA said.

David Fisher, MITA’s executive director, said the reduction in imaging spending and use may be harming Medicare patients:

It is unsettling to see these accelerating declines in Medicare beneficiaries’ use of medical imaging services during a time of tremendous advances in imaging and radiation therapy technologies, which have become increasingly integral to medical best practices and early disease detection. This disconnect raises serious concerns about whether or not patients are receiving the care they need.

Somehow, we can’t see the congressional “super committee” bursting out of its phone booth, or its locked meeting room, or wherever it’s been thrashing out deficit-reduction proposals, and saying, “Sure, cut spending on Social Security, the military, our salaries, and everything else, but we really need to increase Medicare spending on imaging.”

Still, as MITA points out, imaging reimbursements have been cut seven times in six years, with payments for such services as bone density screenings, arm and leg artery X-rays, and brain MRI reduced by more than 60 percent. And further cuts have been proposed. Are Medicare patients in fact now getting second-rate care … well, maybe that’s too strong; let’s say suboptimal care in terms of imaging?

MITA also quotes John A. Patti, MD, chair of the American College of Radiology Board of Chancellors, as saying, “Current evidence, including this analysis, debunks the myth that imaging is significantly overused and somehow responsible for escalating health-care costs.”

Dr. Patti adds:

According to these data, the goal of bending the cost curve has indeed been achieved for medical imaging. Any further reductions would represent socially irresponsible policy.

Of course, the fact that a piece of legislation might be socially irresponsible has never stopped Congress before.

Related seminar: Radiology Review Course

So concludes a preliminary study published online Thursday in Annals of Emergency Medicine. The researchers discovered that patients with TBI had significantly higher blood levels of glial fibrillary acidic protein (GFAP) than those without.

In a statement, Linda Papa, MDCM, said:

This test has the potential for determining injury severity soon after injury, helping emergency physicians make decisions about performing CT scans, seeking neurological consultations, and transferring patients to other facilities.

Dr. Papa, of the department of emergency medicine at Orlando Regional Medical Center in Orlando, Florida, was the study’s lead author. She was quoted by HealthImaging.

The researchers obtained blood samples from 307 adult patients. Of the patients, 108 had TBI, with Glasgow Coma Scale (GCS) scores between 9 and 15, and loss of consciousness, amnesia, or disorientation. The other 199 were control subjects who were either uninjured or had injuries other than TBI. Blood samples were obtained within four hours of injury.

GFAP breakdown product (GFAP-BDP) was found in the blood of the TBI victims. According to the study’s background information, the product is released from injured glia cells.

“GFAP-BDP is detectable in serum within an hour of injury and is associated with measures of injury severity, including the GCS score, CT lesions and neurosurgical intervention,” the study concludes.

The authors said that the study is preliminary and that further research is necessary before a GFAP blood test could be recommended for clinical use. Dr. Papa said it had greater specificity than other blood tests studied for TBI. However, she said, it won’t totally replace imaging:

It is not a substitute for all CT scans, but it could possibly rule out patients who do not need them, as well as ensure that patients at risk get CT scans they need.

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On this Veterans Day, we salute with gratitude those who have have served in the armed forces. We deeply appreciate their sacrifice. It’s also Friday, which means we have a new Facebook post.

Related seminar: Neuro & Musculoskeletal Imaging

Interestingly, the study found that electronic health information exchange (HIE) use increased some types of imaging, notably chest X-rays.

Mark Frisse, MD, professor of biomedical informatics at Vanderbilt University Medical Center in Nashville, led the study. A Vanderbilt news release quoted him as saying:

This is the first study to show that, on a citywide basis, investments in technology can save medical costs by improving care. We took the ‘Tennessee simple’ approach and built a low-cost system that said, ‘Folks, if you do it simply and build it up, doing the right thing can save you money.’

ED physicians used the system, accessed through a secure Web portal, only when they thought it might be useful—which turned out to be 6.8 percent of the time.

Eleven EDs had full electronic access. The 12th did not until the very end of the study period. That hospital, which was the busiest (20 percent of total regional ED visits), relied on printed-out summaries and could inquire for more complete data. The study calls this the “mixed-access group.”

The 13-month study compared nine outcomes: ED-originated hospital admissions, admissions for observation, lab tests, head and body CT scans, ankle and chest X-rays, outpatient surgery, and echocardiograms. Each HIE-use patient was matched with a similar patient for whom doctors did not use the HIE.

Decreased admissions for the HIE-access cases over the 13 months saved $2,059,588, according to the study. CT scans also decreased, but not uniformly. At full-access EDs, head CTs and chest X-rays increased while body CTs and lab tests stayed flat. At the mixed-access hospital, head and body CTs and lab tests decreased while chest X-rays stayed flat.

The study (which is open-access) doesn’t comment on those differences except to say: “We speculate that the small but significant increase in chest X-ray use in inner-city ED within the direct access group is an example of differences in provider motivation.” Knowing the patient population each hospital serves would probably be enlightening, but the study does not identify the hospitals.

Patients could opt out of HIE participation, but only 1 percent to 3 percent did. Dr. Frisse said the system safeguards patient privacy. “It makes available only the information you choose, and it can only be used when you are needing care,” he said. “It is far more secure and useful than paper.”

He is definitely an enthusiast:

Our people believe that the savings from this study are less than 2 percent of the overall savings these technologies can afford if every physician’s office is connected. And we are absolutely convinced and committed to extending this approach to every health care setting.

Related seminar: National Diagnostic Imaging Symposium™