The development of technology is not only helping medical imaging to evolve faster but also has an important impact on other aspects of patient care. There has been an ongoing problem of assisting patients in underserved areas. Not many physicians like to relocate to rural areas and the demand in those geographical locations continues to increase. Also, the same applies to serving third world countries. Big cities have been always attractive to physicians and scientists in general due in part to the convenience of accessing resources.

Telemedicine allows doctors to practice medicine at distance. By saying this, physicians can continue to live in urban locations and practice in rural areas using telemedicine. Technologies such as video conferencing and others, is making this possible. Of course, there are aspects of medicine that do not permit the practice at distance, but certain practices do so, such as- reading imaging scans or pathology slides; following up chronic patients, etc.

Adolfo Cotter, MD

Jul 02/2012

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 ismore 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 althoughthe initial results look promising.

Adolfo Cotter, MD

Feb 12/2012

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 people’s 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, MD

Nov 26/2011

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.

Adolfo Cotter, MD

Aug 03/2011

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, MD

Jun 28/2011

Magnetic Resonance Force Microscopy (MRFM)

Very impressive advancements have been made in this field. The goal is ultimately to visualize matter at the molecular and atomic level. This of course will resolve and hopefully prove many of the questions and mysteries of atomic physics. Ultrahigh resolution 3D images are currently available and they promise to continue to improve. The key elements of this technology are: 1) Ultra small magnetic tips with high moment materials, 2) Ultrasensitive micromechanical cantilevers, 3) Displacement transducers.

MRFM currently surpasses conventional, inductive nuclear resonance detectors by eight times in magnitude. MRFM can continue to improve by further decreasing the size of the magnetic tips and bringing the sample closer to them. 

A good recent review of this technology is the following:

Peggio M., Degen C.L., Force-detected nuclear magnetic resonance: recent advances and future challenges. Nanotechnology. 21 (2010) 1-13

Adolfo Cotter, MD

May 11/2011

Diffusion MRI Tractography as a diagnostic tool for Brain Pathology

Diffusion MRI tractography can be used to evaluate for brain pathology by measuring for pathlength, for example. The pathlength constitutes neuronal brain connectivity between two specified brain locations. An abnormal pathlength could be increased or decreased. A significant change in pathlength should point to a specific brain pathology depending on the location of the path. A recent study on Traumatic Brain Injury shows a significant decrease in path length between the genu of the corpus callosum and the frontal lobe. This white matter structure is often related to diffuse axonal injury (Pannek K, etal. The average pathlength map: A diffusion MRI Tractography-derived index for study of brain pathology. NeuroImage. 55 (2011) 133-141).

Diffusion MRI Tractography is related to structural brain changes. It would be interesting to evaluate for functional brain changes and its relation to functional connectivity. Also, it would be interesting to evaluate for structural connectivity in the so-called functional brain disorders, and find out if they also have a structural component.

Adolfo Cotter, MD

May 11/2011

NY Times article

Last month, a major step forward was taken towards bringing the science of brain imaging into mainstream clinical practice. It appears imminent that the FDA will approve the use of PET  scans for amyloid plaques as a diagnostic test for Alzheimer’s disease.

In my opinion this is a great first step.

Next we should look at combining this test with an anatomical one, such as  MRI , that looks for and measures hippocampal volume. The anatomical test should increase the overall test accuracy.

Although the NY Times article states: “Plaques are part of the criteria for having Alzheimer’s” if a person with memory problems does not have plaques, that person does not have Alzheimer’s it has also been shown that amyloid plaques do not correlate with cognitive changes in Alzheimer’s disease. The ultimate test would be possible only after a more complete understanding of Alzheimer’s disease pathophysiology.

The NY Times article was published on the health section on January 20th 2011.

Adolfo Cotter, MD

Mar 09/2011

Diffraction Enhanced Imaging (DEI)

This is a relatively new imaging technology that uses three “physical mechanisms” to generate contrast. Those mechanisms are: 1) X-Ray absorption, 2) Refraction, 3) Ultra small angle scatter rejection. This technology can produce high contrast images with much lower radiation dose compared to conventional radiography.

One of the applications this technique might be useful for is to image amyloid plaques in Alzheimer’s disease. Those plaques are usually very small and difficult to visualize with other methods.  This technique showed to be useful in a study imaging amyloid plaques in mice.

An interesting paper in the topic is the following:

Parham C, et al. Design and implementation of a compact low-dose Diffraction Enhanced Medical Imaging System. Academic Radiology (2009) August; 16(8): 911-917.

Adolfo Cotter, MD

Feb 10/2011

Track Density Imaging (TDI)

When using MRI, in order to increase spatial resolution we need a longer acquisition time. We also need the same to increase signal to noise ratio (SNR). High tesla MRI, although it increases SNR, it has a problem with deep penetration called the skin effect. Deep structures might be difficult to visualize.

A new post-processing method called TDI seems to be useful to increase spatial resolution and it has a high SNR when imaging the brain white matter. It is also an objective technique and able to be automated. It basically calculates the number of tracts throughout the brain. It seems to help with the crossing fiber problem of fiber tracking by the use of high angular resolution diffusion imaging (HARDI). 

A good paper in the topic is the following:

Calamante F, etal. Track-Density imaging (TDI): Super-resolution white matter imaging using whole-brain track-density mapping. NeuroImage, 53 (2010) 1233-1243.

Adolfo Cotter, MD

Dec 24/2010