Sept. 24, 2008 – The brain clot-busting drug tPA works better the sooner it’s given after stroke, but now a new study shows the treatment can help even if given up to 4.5 hours later.
During a stroke, a clot blocks the flow of blood to parts of the brain. It doesn’t take long for these parts of the brain to start dying. The clot-dissolving drug tPA (tissue plasminogen activator) restores blood flow to the brain, but the drug must be given soon after a stroke to save brain tissue.
1. We do our best work in the dark
2. We can see through your clothes
3. We know all the positions
4. We are well developed
5. The chemistry is always right
6. We know what buttons to push
7. We have all the right techniques
8. We know how to warm up a tube
9. We know how to get the best penetration
10. When you need it now, we make it wet.1
1. Human anatomy is common knowledge.
12. We do it on the table and sometimes we slip it in the bucky.
13. Radiation physics: Hard Beam + Tight Collimation = Adequate penetration
There is a new service available for hospitals and clincs that can determine the mri safety of implanted devices . check out there website.
SEARCHABLE DATABASE: THE NEWEST TOOL FOR MRI IMPLANT SAFETY
The MRI safety status of medical implant devices can be difficult to track because many manufacturers 1.) Change their names; 2) Sell their medical devices to other companies; 3.) Go out of business; 4) Discontinue manufacturing of certain devices; 5.) Merge with other companies; or holding companies move medical device ownership from company to company. Dozens of these transactions transpire annually, bringing confusion and obfuscation to MRI technologists, who need to be certain of an implanted device’s safety status before scanning. After seven or eight years of this merger and acquisition activity, the status of many implants can become impossible to find.
MRI technologists, too often given the sketchiest of information, can spend hours looking for safety status, or materials of construction, to determine if a scan is safe. Even if the search is successful, most sites have no method to ultimately store the data or retrieve it for use later. An MRI site’s source of implant safety information can quickly degrade to a paperback book and an unmanageable manila folder of faxes.
Compounding the problem, are new safety definition standards; more powerful scanners and implants from overseas. Faced with an “MR Conditional” device, technologists must account for the static field strength, spatial gradient field, SAR and time duration of the scan. According to a recent JCAHO Sentinel Event: “All implants should be checked against product labeling or manufacturer literature specific to that implant, or peer-reviewed published data regarding the device or implant in question. Technologists should be provided with ready access to this information.” What JCAHO did not state is where this information is supposed to come from!
A searchable database to store MRI specific information with multiple search options to retrieve manufacturer’s information and published data, would be an invaluable tool to free up technologist’s time and eliminate duplicate research for implant safety information!
MagResource LLC has developed a searchable database to track the MRI safety status of medical implants through this whirlwind of economic and technological turmoil. The Internet database features daily rather than yearly updates to provide site-users with instant access to the latest information. User sites enter the Online Database without login or password. When a device is not found in the database, MagResource will endeavor to find it. Free trials and in-service for MRI sites at: http://www.DoctorDoctor.biz
Initial safety and efficacy data recently presented at the European Society of Cardiology Congress has shown that the investigational EnRhythm MRI SureScan Pacing System from Medtronic Inc., of Minneapolis, may be a potential solution for patients receiving their first pacemaker and needing an MRI scan.
Results from the worldwide clinical study showed no MRI-related complications and no arrhythmia or asystole during MRI scans conducted on patients. Data also demonstrated that hearts responded appropriately to the level of electrical stimulation they received from the device.
According to Medtronic, a small number of patients experienced implant complications consistent with rates for other pacemaker implant procedures, but none were related to the MRI technology.
The EnRhythm MRI SureScan System Clinical Trial is a prospective, randomized, controlled, unblinded, multi-center study involving 470 individuals. The expected study duration and follow up time is approximately 30 months. (source)
The typical brain scan shows a muted gray rendering of the brain, easily distinguished by a series of convoluted folds. But according to Van Wedeen, a neuroscientist at Massachusetts General Hospital, in Boston, that image is just a shadow of the real brain. The actual structure–a precisely organized tangle of nerve cells and the long projections that connect them–has remained hidden until relatively recently.
Traditional magnetic resonance imaging, or MRI, can detect the major anatomical features of the brain and is often used to diagnose strokes and brain tumors. But advances in computing power and novel processing algorithms have allowed scientists to analyze the information captured during an MRI in completely new ways.
Diffusion spectrum imaging (DSI) is one of these twists. It uses magnetic resonance signals to track the movement of water molecules in the brain: water diffuses along the length of neural wires, called axons. Scientists can use these diffusion measurements to map the wires, creating a detailed blueprint of the brain’s connectivity.
On the medical side, radiologists are beginning to use the technology to map the brain prior to surgery, for example, to avoid important fiber tracts when removing a brain tumor. Wedeen and others are now using diffusion imaging to better understand the structures that underlie our ability to see, to speak, and to remember. Scientists also hope that the techniques will grant new insight into diseases linked to abnormal wiring, such as schizophrenia and autism.(source)
see video here
Brain mapping: A variation on MRI called diffusion spectrum imaging allows scientists to map the neural fibers that relay signals in the brain. Each fiber in the image represents hundreds to thousands of fibers in the brain, each traveling along the same path.
Credit: George Day, Ruopeng Wang, Jeremy Schmahmann, Van Wedeen, MGH