Studies in Medical Imaging

PTIFeature Januray 28, 2012      PF-15/2012

Studies in Medical Imaging

By Dr K S Parthasarathy

Researchers can use imaging techniques to assess the microscopic changes in the brain’s white matter, which is composed of millions of nerve fibres called axons that act like communication cables connecting various regions of the brain.

“I have a special feeling for that goal because I scored it with my head,” Pele, the legendary soccer player from Brazil said. It was Brazil’s 100th World cup goal. “My father was a soccer player and once scored five goals in a game, all with his head. That was one record I was never able to break.”

If Pele were present at the 97th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA), he would not have been pleased with some of his soccer exploits.  Michael L.Lipton, associate director of the Gruss Magnetic Resonance Research Center at the Albert Einstein College of Medicine and medical director of MRI services at Montefiore Medical Center in New York and his colleagues  used diffusion tensor imaging (DTI), an advanced imaging technique  and found that players who head the ball with high frequency have brain abnormalities similar to those found in traumatic brain injury (TBI) patients.

Dr Lipton revealed that heading a soccer ball does not have an impact of a magnitude that will lacerate nerve fibres in the brain; but if one does it more often it could set off a cascade of responses that can lead to degeneration of brain cells.

Researchers can use imaging techniques to assess the microscopic changes in the brain’s white matter, which is composed of millions of nerve fibres called axons that act like communication cables connecting various regions of the brain.

Diffusion tensor imaging produces a measurement, called fractional anisotropy (FA), of the movement of water molecules along axons. In healthy white matter, the direction of water movement is fairly uniform and measures high in FA. When water movement is more random, FA values decrease. According to Lipton, low FA within white matter has been associated with cognitive impairment in patients with TBI,

Researchers carried out DTI on 32 amateur soccer players (average age: 30.8 years), all of whom have played the sport since childhood. They estimated how often each soccer player headed the ball on an annual basis and then ranked the players based on heading frequency. They then compared the brain images of the most frequent headers with those of the remaining players and identified areas of the brain where FA values differed significantly.

“Between the two groups, there were significant differences in FA in five brain regions in the frontal lobe and in the temporo-occipital region,” Dr. Lipton said.

Soccer players who headed most frequently had significantly lower FA in these brain regions. The five regions identified by the researchers are responsible for attention, memory, executive functioning and higher-order visual functions.

Dr. Lipton said that they could identify a threshold level of approximately 1,000 to 1,500 heads per year for heading frequency that, when surpassed, resulted in detectable white matter injury. Above this level scientists observed a significant decline in their FA in the five identified brain regions.

If Professor Roentgen were a delegate at the meeting, he would have been shocked to see how medical imaging is used to rake in profit unethically. In a paper presented at the meeting, Dr Ramsey Kilani and his colleagues from Duke University at Medical Centre in Durham, North Carolina, showed that physicians who have a financial interest in imaging equipment are more likely to refer their patients for potentially unnecessary imaging examinations

The paper revealed that “self referral” in which a non radiologist physician orders imaging examination and directs patients to imaging services in which that physician has a financial interest, is a concerning trend in medicine; it is a significant driver of health care costs. In India, there are allegations of nexus between owners of medical imaging equipment and referring physicians.

In another study, a functional magnetic resonance imaging analysis of long term effects of violent video game play on the brain has found changes in brain regions associated with cognitive function and emotional control in young adult men after one week of game play. Thus far there has been little scientific evidence demonstrating that the games have a prolonged negative neurological effect. According to Dr Yang Wang, assistant research professor, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, they found that a sample of randomly assigned young adults showed less activation in certain frontal brain regions following a week of playing violent video game at home.

Dr Cyrus Raji, from the University of Pittsburg  Medical Centre  showed that people who ate baked or broiled fish at least once every week, had better preservation of gray matter volume on Magnetic Resonance Imaging in brain areas at risk for Alzheimer’s disease, an incurable progressive brain disease that slowly destroys memory and cognitive skills

Researchers chose 260 cognitively normal persons from the Cardiovascular Health Study. They gathered information on fish consumption using National Cancer Institute Food Frequency Questionnaire. In the study group 163 persons ate fish on a weekly basis; majority ate fish one to four times per week. Each patient underwent 3D volumetric MRI of the brain.

Researchers used a brain mapping technique that measures gray matter volume to model the relationship between weekly fish consumption and brain structure 10 years later. They analyzed the data to find out whether gray matter volume preservation associated with fish consumption reduced risk for Alzheimer’s disease. The study is complicated as it has to be controlled for age, gender, education, race, obesity, physical activity and the presence or absence of a gene that increases the risk of developing Alzheimer’s disease. Consumption of fish on a weekly basis was found to be positively associated with gray matter volumes in many areas of the brain.

The annual meeting (November 27 to December 2 this year) of the RSNA at Chicago attracts attention worldwide. Attendees contributed $ 133 million to Chicago’s economy. Virtually all the papers presented looked like hurried jobs done for the sake of the conference. The most important activity is six days of educational programmes (233 refresher courses and 127 multi-sessions) for radiologists, radiation oncologists, and physicists in medicine, radiologic technologists and allied professionals


About ksparthasarathy

I am a former Secretary of the Atomic Energy Regulatory Board. I am a former Raja Ramanna Fellow in the Department of Atomic Energy. Free lance journalism is my hobby
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s