neurology

Lightweight, open, mobile, cheaper MRI brain scanner prototype working in lab

Attila Csordas — Wed, 17 Sep 2008 15:13:20 -0700

Description

Those giant, claustrophobic, tunnel forming magnets used for magnetic resonance imaging (MRI) in labs and hospitals look so last century! They are pricey and heavy, making MRI systems immobile and demanding to install. Any alternative? Yes by implementing the pre-polarized MRI concept introduced some 15 years ago:

"Writing in the Journal of Magnetic Resonance, Vadim Zotev and colleagues report success in imaging a human brain using a different type of MRI system: lightweight, open, mobile and significantly cheaper.

By dividing the functions of these large-field magnets between two sets of magnets with different characteristics, Zotev et al. have produced the prototype of a machine that would be smaller and more open, as well as being capable of performing magnetic resonance imaging and magnetoencephalography at the same time.

Conventional MRI machines reconcile these different requirements by using magnets that are both powerful and homogeneous. But could the same effect be achieved by using two simpler magnets and switching between them? The first magnet, strong but relatively inhomogeneous, would polarize the sample, whereas the second, weak but highly homogeneous, would be optimized for collecting resonance signals. This concept, termed pre-polarized MRI, was originally introduced by Macovski and Conolly2 some 15 years ago, and has been pursued by several research teams since.

Zotev et al. now report obtaining images of a living human brain using pre-polarization at 30 millitesla (mT) and image data collection at just 46 microT, a similar strength to that of Earth's magnetic field and about 30,000 times weaker than that of typical clinical MRI machines. Using such small magnetic fields means that the frequencies of the signals produced by the oscillating nuclear spins are similarly reduced from the usual radiofrequency range to around 2 kilohertz — a frequency readily audible to the human ear (approximately three octaves above middle C)."

Biomedical Sciences and Biotechnology

Source

Klaas P. Pruessmann: Medical imaging: Less is more
Nature 455, 43-44 (4 September 2008) | doi:10.1038/455043a
http://www.nature.com/nature/journal/v455/n7209/full/455043a.html

Zotev et al.: Microtesla MRI of the human brain combined with MEG.
J Magn Reson. 2008 Sep;194(1):115-20.
http://www.ncbi.nlm.nih.gov/pubmed/18619876?dopt=Abstract&holding=npg

Investigation of Harvard psychiatrists highlights inadequate regulation of commercially funded research in academic institutions

Katy Armstrong — Tue, 17 Jun 2008 19:10:13 -0700

Description

Joseph Biederman and Timothy E. Wilens, both Harvard professors of psychiatry, are under investigation for failing to report millions of dollars in "consultant fees" received from pharmaceutical companies over the past decade. Both professors received government research grants requiring disclosure of any additional research monies received. In addition, Harvard limits the amount of corporate funding for conducting clinical trials to $10K, so the researchers appear to be in violation of multiple regulations designed to limit potential conflicts of interest between publicly funded basic research and corporation-backed translational research.

In addition to emphasizing the need to improve the execution of existing regulations, and possibly expand them further such as through the creation of a national research funding registry, news of the investigation also casts a cloud of doubt on the scientist's research. Dr. Biederman's research, for example, promotes the treatment of antipsychotic drugs in young children to treat bi-polar disorder. Both the disease, and its treatment, are controversial topics fraught with questions about the subject nature of diagnosis, concerns over the long-term effects of medication as well as possible developmental consequences.

Ethics in Science

Source

http://www.nytimes.com/2008/06/08/us/08conflict.html?ref=health

controlled study confirms high fat diet can effectively treat epilepsy in children

Katy Armstrong — Wed, 07 May 2008 13:14:29 -0700

Description

A study (to be published in June 2008) by a team of neurologists at the University College London recently completed the first randomized trial of a controversial high-fat diet that has been used to treat children with epilepsy. The study of 145 children confirmed that a high-fat diet is an effective treatment for epileptic seizures in children, reducing the frequency of seizures by up to 90%.

This work provides solid evidence that " lays to rest the issue of ‘Does it really work or not?’" (1), according to Dr. Shlomo Shinnar, the director of the Comprehensive Epilepsy Management Center at the Montefiore Medical Center in the Bronx. Dr. Shlomo's comment addresses the fact that although high-fat diets have been used to treat epilepsy since the 1920s, it has previously been dismissed by many doctors as a "marginal alternative therapy" (1).

Source

1) Previewed in the NY Times: http://www.nytimes.com/2008/05/06/health/research/06epil.html?_r=1&ref=science&oref=slogin

Article will appear in The Lancet Neurology in June 2008: http://www.elsevier.com/wps/find/journalaudience.cws_home/622235/description?navopenmenu=-2