March 20th, 2011 by American Journal of Neuroradiology in Research
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We report a pathologically proved craniopharyngioma in the prepontine cistern. A 50-year-old woman presented with swallowing difficulty for 1 month. She underwent brain MR and CT imaging.
T1-weighted, T2-weighted, and contrast-enhanced T1-weighted images showed a large peripheral enhancing cystic mass in the prepontine cistern. Inside the lesion, high signal intensity (SI) on T1 and low SI on T2-weighted imaging were noted (Fig 1). The CT scan showed features similar to those on the MR images, except for the addition of a peripheral small calcification in the cystic lesion. We could not find any connection between the mass in the prepontine cistern and the sellar or parasellar area. The mass was partially surgically removed, and histopathologic examination revealed craniopharyngioma in the prepontine cistern.
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[in a new window]- Fig 1. A 50-year-old woman with a craniopharyngioma in the prepontine cistern. A, Sagittal T1-weighted image shows a cystic mass in the prepontine cistern. B, Contrast-enhanced T1-weighted sagittal image shows a peripheral enhancing cystic mass in the prepontine cistern. Read more »
*This blog post was originally published at AJNR Blog*
March 17th, 2011 by Shadowfax in Health Tips, True Stories
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I’ve remarked in the past how rarely I ever learn anything useful from physical exam. It’s one of those irritating things about medicine — we spent all that time in school learning arcane details of the exam, esoteric maneuvers like pulsus paradoxus, comparing pulses, Rovsing’s sign and the like. But in the modern era, it seems like about half the diagnoses are made by history and the other half are made by ancillary testing. Some people interpreted my comments to mean I don’t do an exam, or endorse a half-assed exam, which I do not. I always do an exam, as indicated by the presenting condition. I just don’t often learn much from it. But I always do it.
The other day, for example, I saw this elderly lady who was sent in for altered mental status. There wasn’t much (or indeed, any) history available. She was from some sort of nursing home, and they sent in essentially no information beyond a med list. The patient was non-verbal, but it wasn’t clear if she was chronically demented and non-verbal or whether this was a drastic change in baseline. So I went in to see her. I stopped at the doorway. “Uh-oh. She don’t look so good,” I commented to a nurse. As an aside, this “she don’t look so good” is maybe 90% of my job — the reflexive assessment of sick/not sick, which I suppose is itself a component of physical exam. But I digress. Her vitals were OK, other than some tachycardia*. Her color, flaccidity and apathy, however, really all screamed “sick” to me. Of course, the exam was otherwise nonfocal. Groans to pain, withdraws but does not localize or follow instructions. Seems symmetric on motor exam, from what I can elicit. Belly soft, lungs clear. Looks dry. No rash. Read more »
*This blog post was originally published at Movin' Meat*
February 28th, 2011 by Elaine Schattner, M.D. in Opinion, Research
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There’s a new study out on mammography with important implications for breast cancer screening. The main result is that when radiologists review more mammograms per year, the rate of false positives declines.
The stated purpose of the research*, published in the journal Radiology, was to see how radiologists’ interpretive volume — essentially the number of mammograms read per year — affects their performance in breast cancer screening. The investigators collected data from six registries participating in the NCI’s Breast Cancer Surveillance Consortium, involving 120 radiologists who interpreted 783,965 screening mammograms from 2002 to 2006. So it was a big study, at least in terms of the number of images and outcomes assessed.
First — and before reaching any conclusions — the variance among seasoned radiologists’ everyday experience reading mammograms is striking. From the paper:
…We studied 120 radiologists with a median age of 54 years (range, 37–74 years); most worked full time (75%), had 20 or more years of experience (53%), and had no fellowship training in breast imaging (92%). Time spent in breast imaging varied, with 26% of radiologists working less than 20% and 33% working 80%–100% of their time in breast imaging. Most (61%) interpreted 1000–2999 mammograms annually, with 9% interpreting 5000 or more mammograms.
So they’re looking at a diverse bunch of radiologists reading mammograms, as young as 37 and as old as 74, most with no extra training in the subspecialty. The fraction of work effort spent on breast imaging –presumably mammography, sonos and MRIs — ranged from a quarter of the group (26 percent) who spend less than a fifth of their time on it and a third (33 percent) who spend almost all of their time on breast imaging studies. Read more »
*This blog post was originally published at Medical Lessons*
February 18th, 2011 by Mary Knudson in News, Opinion
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This was the Guest Blog at Scientific American on February 16th, 2011.
New wave of MRI-safe pacemakers set to ship to hospitals
This week Medtronic will begin shipping to hospitals in the United States the first pacemaker approved by the FDA as safe for most MRI scans. For consumers, it is a significant step in what is expected to be a wave of new MRI-compatible implanted cardiac devices.
But this is an example of one technology chasing another and the one being chased, the MRI scanner, is changing and is a step ahead of the new line of pacemakers. The pacemaker approved for U.S. distribution is Medtronic’s first-generation pacemaker with certain limitations, while its second-generation MRI-compatible pacemaker is already in use in Europe where approval for medical devices is not as demanding as it is in the U.S. So let’s check out what this is all about — what it means now for current and future heart patients and where it may be headed.
We are all born with a natural pacemaker that directs our heart to beat 60 to 100 times a minute at rest. The pacemaker is a little mass of muscle fibers the size and shape of an almond known medically as the sinoatrial node located in the right atrium, one of four chambers of the heart. The natural pacemaker can last a lifetime. Or it can become defective. And even if it keeps working normally, some point may not function well along the electrical pathway from the pacemaker to the heart’s ventricles which contract to force blood out to the body.
Millions of people in the world whose hearts beat too fast, too slow, or out of sync because their own pacemaker is not able to do the job right, follow their doctors’ recommendation to get an artificial pacemaker connected to their heart to direct its beating. The battery-run pacemaker in a titanium or titanium alloy case the size of a small cell phone, (why can’t it be the size of an almond?) is implanted in the upper left chest, just under the skin, with one or two insulated wire leads connecting to the heart. It can be programmed to run 24/7 or to only operate when the heart reaches a certain state of irregular beating. Read more »
*This blog post was originally published at HeartSense*
February 15th, 2011 by KevinMD in Better Health Network, Opinion
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Abdominal pain is the bane of many emergency physicians. Recently, I wrote how CT scans are on the rise in the ER. Much of those scans look for potential causes of abdominal pain.
In an essay from Time, Dr. Zachary Meisel discusses why abdominal pain, in his words, is the doctor’s “booby prize.” And when you consider that there are 7 million visits annually by people who report abdominal pain, that’s a lot of proverbial prizes.
One reason is the myriad of causes that lead bring a patient to the hospital clutching his abdomen. It can range from something as relatively benign as viral gastroenteritis where a patient be safely discharged home, to any number of “acute” abdominal problems necessitating surgery.
But more importantly, we need to consider how limited doctors actually are in the ER. Consider the ubiquitous CT scan, which is being ordered with increasing regularity:
The pros: CT scans are readily available, able to look at every organ in the abdomen and pelvis, and very good for ruling out many of the immediately life-threatening causes of belly pain. CT scans can also reduce the need for exploratory surgery. The cons: Often, CTs can’t diagnose the actual cause of ER patients’ abdominal pain. Worse, CTs deliver significant doses of radiation to a patient’s abdomen and pelvis (equivalent to between 100 and 250 chest X-rays). Over a lifetime, patients who receive two or three abdominal CT scans are exposed to more radiation than many Hiroshima survivors.
Add that to the fact that patients expect a definitive diagnosis when visiting the hospital — one that doctors can’t always give when it comes to abdominal pain. Read more »
*This blog post was originally published at KevinMD.com*
