Faster MRI?

May 15, 2012

 

Researchers from the Children’s National Medical Center in Washington, D.C (principal researcher: Stanley Fricke) have recently published a study in Medical Physics where they show that ultra-fast magnetic gradients (pulse sequences with rise times 100 times faster than conventional MRI) do not produce nerve stimulation or muscle twitching. According to the researchers, MRI limiting speed should be revisited taking into account the new developments, and they expect MRI to allow imaging of small children in seconds rather than minutes.

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Last February, a group of Canadian researchers presented at the American Academy of Orthopeadic Surgeons (AAOS) a new study about the interpretation of MR images on the iphone.

Smartphones are becoming part of every activity of our lives, and this is also true for physicians and hospitals. The advantage is that they are portable and most of the time on the pocket or handbag, but the question is whether they are good enough for a medical diagnosis.

According to Dr. John Theodoropoulos, an orthopedic surgeon from the University of Toronto, “iPhone interpretations showed high sensitivity and specificity for medial meniscus and cruciate ligaments injuries with lower sensitivity for lateral meniscus tears and lower specificity for cartilage injuries.  And compared to much larger the PACS workstation interpretation on a flat screen, the iPhone showed excellent agreement for medial meniscus and cruciate ligament injuries and good agreement for cartilage injuries”. However, Dr. Theodoropoulos said that the iPhone app missed two cartilage tears versus the full-sized workstation.

Maybe we are not there yet, but the smartphones and tablets certainly look promising for medical image interpretation and have many features that make them very attractive, specially for emergency cases.

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Radiation-blocking underwear…

September 13, 2010

Airport X-ray scanners is the latest security measure that you have to go through before boarding a plane in the US. But, how safe are they? A lot to discuss about it… So far, you still got the option of getting a pat down. So no need to worry too much, right? Well, if you belong to those that think that soon there’ll be x-ray scanners everywhere, from schools to museums, etc., a company (Rocky Flats Gear) seems to have found the solution for you: ‘radiation-blocking’ underwear.
This all sounds very nice, but what happens with the rest of the body, doesn’t it get affected by radiation? Soon, we’ll have to be walking around on ‘radiation-blocking’ clothes. And the head? use an astronaut-like mask? How far can we go with those ”prevention” measures?

The U.S. Food and Drug Administration has just updated the regulations regarding warning labels on gadolinium-based MRI contrast agents, due to the risk of NSF.
From now on, Magnevist, Omniscan, and Optimark would be required to carry labels with the following warning: “inappropriate for use among patients with acute kidney injury or chronic severe kidney disease.” The labels will emphasize the importance of screening patients to detect kidney dysfunction before MRI contrast administration.
According to the FDA, the latest review of the safety of the most widely used gadolinium-based contrast agents “determined that Magnevist, Omniscan, and Optimark are associated with a greater risk than other [gadolinium-based contrast agents] for NSF in certain patients with kidney disease.” However, all gadolinium-based contrast agents are under study, as data suggests that NSF may follow the administration of any of them.

On January, the 8th, an article appeared in Diagnostic Imaging, which analyzes the safety issues concerning whole-body airport scanners. Since the attempted attack inside an airplane flying from Amsterdam to Detroit last December, most airports are planning to install whole-body scanners to scan passengers. However, not much is really known about the health risks.
You can read more about the research conducted so far, in the following two articles:
http://abcnews.go.com/Health/CancerPreventionAndTreatment/experts-radiation-fears-full-body-scans-unfounded/story?id=9476542&page=1
http://arxiv.org/abs/0910.5294

MRI issues: pacemakers

January 12, 2010

A recent study by FDA researchers has shown the risks of MR scanning patients with pacemakers. This is normally contraindicated, but some physicians condone scanning certain patients. FDA researchers found that certain cardiac pacemakers may inadequately stimulate a patient’s heart while undergoing an MRI scan. For a full report, see:
http://www.biomedical-engineering-online.com/content/8/1/39

Stroke imaging by CT perfusion has exposed more than 200 patients to radiation poisoning in Cedars-Sinai Medical Center in Los Angeles only. But this is just an example of a problem emerging in many medical centers. This has led the FDA authorities to issue a set of preemptive recommendations for the use of CT perfusion. The rapid developments of CT imaging in the last couple of years has led to a significant increase in CT scans, sometimes without taking into account the risks associated to radiation. For more information, take a look at the following links:
http://www.diagnosticimaging.com/display/article/113619/1491688
http://www.diagnosticimaging.com/display/article/113619/1475485
http://www.diagnosticimaging.com/display/article/113619/1491848