MODERN BRAIN SCANNING TECHNOLOGY OFFERS SIMPLE LOOK AT EVERYTHING FROM HEAD TRAUMA TO TUMORS

The Charles M. and Marilyn Newman Professor and Chairman of Radiology at Mount Sinai, Drayer has been a radiologist specializing in the brain and spine for 30 years.

WHO’S AT RISK:

Thanks to advances in MRI and CT technology, doctors can get highly detailed images of the brain, a procedure used for patients with a wide variety of conditions. “Any patients with neurological or psychiatric symptoms might require an image of their brain, including patients [suffering from] stroke, brain tumor, multiple sclerosis, brain infections, Alzheimer’s, Parkinson’s and head injury,” says Drayer.

As for groups at risk, “The same group at risk of heart attack is at risk of stroke, which some people call a ‘brain attack,’ ” says Drayer. “The warning signs of stroke are called TIA [transient ischemic attack], and people with high blood pressure, diabetes and a history of smoking are at higher risk.” Alzheimer’s and Parkinson’s diseases are associated with advancing age, while brain-tumor and head-trauma patients can be any age, including children, teenagers and otherwise healthy young adults.

SIGNS AND SYMPTOMS:

Doctors have identified a cluster of symptoms that most often bring people in for brain imaging. “Key signs are weakness or numbness, often on one side of the body, loss of speech, vision or hearing, dementia or loss of memory, confusion, involuntary movements and headaches,” says Drayer. “Anyone who is acutely becoming weak or losing their speech should immediately come to an ER in a stroke center that is equipped to prevent the more severe consequences.”

Many neurological conditions will affect one side of the body more than the other. “That’s because a condition affecting one side of the brain usually causes symptoms on the other side of the body,” says Drayer. “For instance, if the tumor is on the right side of the brain, they might have symptoms in the left arm or leg.”

The standard test for people who have suffered head trauma is a CT scan. “That’s now routine,” says Drayer. “If you’ve had severe head trauma, we scan to see if there’s blood on the brain.” Alzheimer’s and Parkinson’s patients most often present with symptoms such as memory loss and tremors or other involuntary movement.

Some patients pick up on their own symptoms, and sometimes doctors or family members note them. “Some patients have chronic problems, others subacute problems, others acute problems — for example, after an auto accident or a stroke,” says Drayer. “At some point they need an image, an MRI or CT scan, to help determine their course of treatment.”

TRADITIONAL TREATMENT:

Modern brain imaging is light-years ahead of the technology in use as recently as 1970. “Traditionally, imaging of the brain was very invasive and difficult,” says Drayer. “For example, for the brain you would do a pneumoencephalogram, where doctors did a spinal tap and inserted air into spinal fluid.

“It was kind of barbaric,” says Drayer, “but it was the best thing we had in 1970.” The patient often had to be hospitalized for a week to recuperate from this diagnostic procedure.

New technology is fast, noninvasive and usually painless. “Now we do an MRI or CT scan to image the brain or spine,” says Drayer. “It takes five minutes for a CT scan or 45 for an MRI. What used to take a week in the hospital and wasn’t as accurate, now takes only 45 minutes and is accurate to millimeter resolution.” The images are now digital, and instead of running X-ray films around the hospital, doctors can read them immediately at work stations and share them with referring physicians or the patient.

In the past, imaging was only diagnostic. “We used it to find out: ‘Do you have a disease or don’t you have a disease?’ ” says Drayer. “Now we use imaging for prevention and therapy as well. Interventional neuroradiologists are treating disease rather than just diagnosing it. ... Imaging is giving information at the molecular level to see biochemical and physiological events in the brain,” says Drayer. “This helps us understand the underpinning of the disease.”

“CT scans are extremely quick and simple,” says Drayer. “There is radiation involved, so we try to keep the dose as low as possible.” These scans are good for very sick and unresponsive patients and are especially good for determining if there is acute blood on the brain, which is why they are standard in cases of head trauma. CT is also used during the acute stroke phase.

The highly sensitive MRI is the scan familiar from television; the patient lies down and enters a tubular chamber. “The MRI can be a little claustrophobic, but 95% of patients handle it well,” says Drayer. “It provides much more elegant and complete information.” Doctors choose MRI scans — which usually last about 45 minutes — for what Drayer calls “healthy sick people,” such as those with a neurological or psychiatric problem who are otherwise healthy — for example, a young woman with transient weakness or loss of vision being checked for multiple sclerosis.

PET scans are becoming more important in brain imaging. “This is molecular imaging — it defines the biochemistry of the disease,” says Drayer, who explains the scans are commonly used for following the progress of brain tumors and Alzheimer’s disease.

These tests are also extremely accurate: “We can see things in the brain that are a millimeter in size.”

RESEARCH BREAKTHROUGHS:

Now that the technology for CT, MRI and PET scans is so advanced, doctors think the next big breakthroughs will be in understanding how the brain works. “Eventually, we’ll be able to look at the brain not just when it has a disease — like stroke, Alzheimer’s — but when it is normal and we understand how it works,” says Drayer. “Already we use functional MRI to show for example, that if you’re a professional musician, your brain works differently from a nonmusician; if you’re a professional golfer, your brain works differently when you hit a golf ball than a less experienced golfer.”

The next steps for brain imaging will be for doctors to determine individuals who are more prone to developing chronic diseases like Alzheimer’s and Parkinson’s; they can then lay the groundwork for preventing or delaying the onset of these debilitating disorders.

QUESTIONS FOR YOUR DOCTOR:

A good question to start with is, “Could I benefit from a CT or MRI scan?” Your internist, neurologist or neurosurgeon will determine whether you are a good candidate.

Another good question is, “What are the risks?” For MRI, there is no risk except the discomfort of lying in the MRI machine. “In cases of severe claustrophobia, some people need to be sedated to help them through the exam,” says Drayer. For CT scans, the risk is the radiation intrinsic to the exam, but most centers are very diligent about using the lowest possible dose.

(Source: CNN DailyNews, June 3, 2009)