Reliability of Quantitative Diffusion Tensor Tractography
MRI Difussion Tensor Imaging has been used to evaluate for structural brain connectivity lately, a technique that has been traditionally done using pathological methods. DTI is based on water diffusion along the brain fiber tracts. The complexity of the brain fibers is a challenge. In a recent study by Wang YV. et al ( A comprehensive reliability assessment of quantitative diffusion tensor tractography, NeuroImage 2012, 60: 1127-1138); It shows that DTI tractography should be a reliable method in cases where the track size is not too small and in brain regions where the water diffusion directionality is not too low. They showed that a way of improving the reliability and accuracy is by increasing the number of gradient directions and by scan repetition. They based these conclusions by retesting and evaluating for inter and intra reliability.
It
would be interesting, in my opinion, to compare this method with known
pathological techniques.
Adolfo Cotter
Magnetic Resonance Electrical Impedance Tomography (MREIT)
I find this technology very interesting as an adjunct to EEG. During EEG the electrical activity of the brain is captured at the surface of the scalp. Differences in brain conductivity can alter the EEG recordings. MREIT can help refine EEG source localization by giving information on the brain conductivity by region. Also MREIT could be useful to help understand better the mechanisms behind EEG recordings.
An interesting paper on this topic is the following:
Minhas AS, et al. Experimental Performance Evaluation of Multi-Echo ICNE Pulse Sequence in Magnetic Resonance Electrical Impedance Tomography. Magnetic Resonance in Medicine (2011) 66: 957-865
Adolfo Cotter
Susceptibility Tensor Imaging (STI)
STI is a new MRI technology in development. It consists on creating images and contrast based on the susceptibility of the tissue to the magnetic field. This susceptibility seems to be based to the anisotropic alignment of the molecules. The tissue is more susceptible when the angle to the magnetic field is smaller. A recent study in mouse, (Chunlei L. et al. 3D fiber tractography with susceptibility tensor imaging. NeuroImage (2012) 59: 1290-1298), shows a similar contrast to Diffusion Tensor Imaging (DTI), although DTI seems to be superior in small and complex fibers.
It would be interesting
to compare STI to neuroanatomical tract tracing, since pathology is still the
gold standard. This is a new technology that needs more development although
the initial results look promising.
Adolfo Cotter
Do experiments really help us understand reality better?
The question I have is if experiments and gathering information from reality with our senses is better than just logical reasoning and thinking. Apparently it is, but I think we have to analyze this situation better using our current knowledge of Neuroscience and Imaging, for example, in order to arrive to a more definite conclusion. We might be surprised.
Adolfo Cotter
Too Good to be True...
You hear it often: “that’s too good to be true.” A long list of hucksters and criminals have used the method of offering exceptionally good opportunities in order to steal peoples’ money in the past, and so our society does not believe in fantastic opportunities anymore. This is very sad and dangerous for true and generous people who are now usually mistaken for being liars and criminals whenever they might “go too far” in presenting the virtues of an opportunity. In other words, true criminals who have been using this method, not only have committed the criminal act, but have deeply hurt our society by not allowing truly exceptional people to prosper. This in consequence has diminished the number of real outstanding opportunities.
At NeuroImage we thrive to provide exceptional service. We do hope our clients will not think about us as “Too good to be true…!”
Adolfo Cotter
Argument vs. Diplomacy
Adolfo Cotter
Utility of the Scientific Method
Saying this, I believe we should find new methods that can be more suitable for the other elements of nature.
Adolfo Cotter
The Instant Information Age Should Transform The Way We Learn And Educate
With so much data so readily available, the training of new professionals can now emphasize “understanding" the concepts and the inner structure of the field of study, learning how to look at the information critically, and learning how to think. Also, a very good knowledge on how to use the new technology is crucial.
While too much information bombarding our minds is not fertile ground for creativity, if we learn to use the technology properly, it allows our brains to be more creative and even more efficient. This could be a big step forward in how well we learn. I think our educational system should adapt to this new change.
Adolfo Cotter
Neurology and Legal Medicine
I find this combination of specialties fascinating.
In my opinion, Neurology has been, and still is in large part a diagnostic specialty, whereas the main goal of medicine is to resolve patients’ clinical problems. Hopefully with more R&D, neurological treatment will become more useful. Unfortunately, up until now where the practice of Neurology has been used to affect clinical outcomes, practitioners and patients are often hampered by unacceptable medication adverse event profiles to achieve symptomatic relief, and outright cures are seldom achieved. This is why Pharmaceutical and Biotechnology R&D in this area is crucial and is thankfully now moving forward faster than ever before.
In the meantime, combining neurological knowledge and diagnosis with a discipline such as legal medicine for example would allow physicians in this field to be more useful to their patients. In this context, neurologists who otherwise are not surgeons would be able to diagnose illnesses and use their legal tools to help patients better. For example, what about using their expertise to help patients get insurance benefits or resolve medico-legal or medical malpractice issues? Ideally this could be combined with the practice of Neurology itself. I encourage neurologists to take a look at The American Board of Legal Medicine web site, www.ablminc.org/index.htm, and the American College of Legal Medicine web site at www.aclm.org
Adolfo Cotter
Transcranial Doppler (TCD)
TCD is the only non-invasive real-time neuroimaging study that can evaluate the characteristics of cerebral blood flow continuously. CT Angiography (CTA) and Magnetic Resonance Angiography (MRA) can do snapshots in time. Fluoroscopic angiography is the gold standard and can be used as a confirmatory tool.
Some of the applications of TCD are: stroke, vasomotor reactivity testing, emboli monitoring, shunt detection, increased intracranial pressure, circulatory arrest, monitoring vasospasm after spontaneous subarachnoid hemorrhage, and sickle cell anemia.
In my opinion TCD can be a good test in the assessment of brain death when the diagnosis is doubtful.
A good review paper in this topic is the following:
Tsivgoulis G, et al, Advances in Transcranial Doppler Ultrasonography. Current Neurology and Neuroscience Reports, 2009, 9:46-54
Adolfo Cotter
