November 25th, 2007 by Dr. Val Jones in Expert Interviews
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My former mentor, Dr. Richard Robb, is Director of the Biomedical Imaging Resource Center at the Mayo Clinic, Rochester, Minnesota. I first met Dr. Robb as a Summer Undergraduate Research Fellow (SURF) in the Department of Biophysics at Mayo in 1994. Behind his reserved exterior is a man who is bursting with enthusiasm about the amazing technological advances that are making it possible for us to see cells, tissues, and organs in ways barely conceived of several decades ago. Dr. Robb admits that his passion for improving the quality of anatomical visualization is a response to a challenge once given him by a neurosurgeon colleague: “If I can see it, I can fix it.” Dr. Robb’s life’s work is to enable physicians and surgeons to be more effective healers through direct visualization of anatomy and physiology.
I caught up with Dr. Robb (at the Society for Women’s Health Research briefing on imaging and women’s health) and asked him a few questions about the future of medical imaging. Here are some excerpts from our interview:
Dr. Val: What is micro CT and what information does it give doctors?
Dr. Robb: Micro CT is a specialized kind of scanner that works on the same principles as regular CT scanners but it can capture images at much higher resolution. Structures as small as 5-10 microns in size can be seen. Although this is an emerging technology used primarily for research purposes, it has tremendous potential and implications for the future. With such resolution, we’ll be able to do “virtual biopsies” of suspicious tissue that we find with a regular CT and then zoom in with the Micro CT to get a close look at microscopic detail without having to do a biopsy to study them.
Dr. Val: What is SISCOM and who benefits from it?
Dr. Robb: SISCOM is an acronym for “Subtraction Interictal Spect COregistered to Mri.” It is used to pinpoint small parts of the brain that cause epileptic seizures, so that surgeons can effectively remove the diseased tissue. SISCOM uses radioactive tags that are absorbed by the parts of the brain that are over-active during a seizure, and they glow like a lightbulb on SPECT brain scans that are subtracted and registered onto MRI scans. The radiologist can pinpoint the exact focus of the abnormal epileptic discharges and then show the surgeons exactly where they need to resect the tissue. This technique allows surgeons to cure many patients who suffer from seizures that don’t respond to medications.
Dr. Val: What is the most exciting new imaging technology under development and how will it impact health?
Dr. Robb: The most exciting future technologies will allow us to visualize tissue functions at a chemical level. In the next 10 years we’ll see major advancements in image resolution and micro imaging techniques, and eventually we’ll be able to see individual molecules. This technology could actually eliminate the need for surgical biopsies, replacing them with “virtual or digital biopsies”, including close up images of cells and chemical reactions, such as diffusion, all in the context of surrounding macro-sized structures. The effect of the chemical actions and reactions will be expressed visually at the organ function level.
Also, in the next 10-20 years the development and clinical use of “nanobots”, or tiny robotic elements, that can be ingested or injected into the body will become manifest. These may be used with special biomarkers – substances that preferentially label tissue types and pathology within the body. These traveling nanobots can, for example, either go to the biomarkers or expore intelligently certain anatomic domains, taking pictures inside GI tracts, pulmonary airways, or even blood vessels. They will then analyze these images for detection and characterization of abnormalities (like a polyp) followed by administering treatment to the abnormality (e.g., remove it by ablation or radiation or chemicals). The nanobot will remain in the body until it has removed or repaired the targeted pathology or trauma, then it will exit through natural means or “self-destruct” in a safe way. Nanobots could reduce the need for more invasive surgeries, and dramatically improve clinical outcomes with very low risk and morbidity.
This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
November 14th, 2007 by Dr. Val Jones in News, Opinion
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“Grow old along with me! The best is yet to be, the last of life, for which the first was made.”
— Robert Browning
As a rehabilitation medicine specialist I do a lot of work with cognitively impaired men and women. The brain is a fragile and fascinating organ, and perhaps the most perplexing one to treat. Alzheimer’s disease, of course, has no known cure – and those who contract it meander through a frustrating cognitive web towards a final common pathway of dementia, dependence and eventually death.
Former Chief Justice Sandra Day O’Connor has been in the news lately because her husband, an Alzheimer’s patient who requires nursing home assistance for activities of daily living, has forgotten who she is. But even more emotionally difficult is the fact that he has fallen in love with a fellow nursing home resident, and has been behaving like a love-sick teen – holding hands, staring into her eyes and kissing her tenderly.
The New York Times reports that Ms. O’Connor is “happy for her husband” that he has found joy in the midst of his cognitive decline. I wonder if there truly isn’t part of her that mourns the loss of those kisses that were once for her.
My fondest hope is that I can grow old with my husband, and that we will enjoy our final years together, in possession of all our faculties. I hope that Robert Browning’s poem will ring true at the end, and that I never have to watch my husband forget who I am. Sadly, since my grandmother passed away from Alzheimer’s – I wonder if it will be my husband, and not me, who watches the other decline?This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
November 13th, 2007 by Dr. Val Jones in Expert Interviews, News
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Sadly, four transplant patients in the Chicago area recently discovered that their new organs were infected with HIV and hepatitis C. This is the first case of infected organ donation in the past 20 years, with over 400,000 successful, healthy transplants completed in that time period.
I’m actually a little surprised that this is the only known case of infected organ transplants in the past two decades, since the tests to rule out HIV and hepatitis C rely on antibodies. It takes the body at least three weeks to produce antibodies to these viruses, and so people who are infected with HIV and hepatitis C have false negative tests for the first few weeks. So there is always the risk that an organ donor could have contracted these viruses within 3 weeks prior to his or her death.
I asked Dr. David Goldberg, an infectious disease specialist in Scarsdale, NY, to weigh in:
Are there any tests available now that can detect the viruses themselves, or only antibodies? How early after infection could we detect them?
Traditional serologies measure antibodies against the viruses which take weeks or months to develop, whereas there is a more rapid test, called “PCR,” that is a direct measure of the number of viruses in the blood.
HIV reproduces rapidly, so the virus can usually be detected in the bloodstream within 8 days of infection. By contrast, hepatitis C virus replicates more slowly, so the virus may not be detectable until as long as 8 weeks after exposure. So the use of the HIV PCR test in addition to antibody tests would pick up almost all cases of HIV, but the hepatitis C PCR might still miss a number of early infections.
How can we protect future organ recipients from such a tragic event?
PCR is not generally performed because the test is time-consuming and many organ donors are trauma victims, which leaves little time for testing. However, PCR testing could theoretically reduce the number of HIV infected organs that are transplanted (from recently infected individuals), but would not improve the odds in hepatitis C because of the slow growing nature of the virus. In the end there’s no perfect test or 100% guarantee that organ donors don’t have HIV or hepatitis C.
This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
November 13th, 2007 by Dr. Val Jones in Health Tips, News
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Diabetes is a tricky disease. Sugar build up in the blood stream can damage tiny blood vessels that supply nerve endings, resulting in skin numbness. The feet are at the highest risk for nerve damage (neuropathy) and folks with diabetes often cannot sense pain in their feet.
How many of us have gotten blisters from ill fitting shoes? Painful, right? Well imagine if you didn’t feel the pain of the blistering and kept on walking, oblivious to the injury. Eventually you’d have a pretty bad sore there. This is what happens to people with diabetes who don’t choose their shoes carefully. In addition, sores don’t heal well because of the decreased blood supply to the area (from the damaged blood vessels). And to top it off, the high sugar levels in the sores provides additional sustenance to any bacteria that might be lurking on the skin. It’s pretty easy for diabetics to develop infected wounds, which can grow larger and even require amputations of dead tissue.
A recent research study suggests that the secret to avoiding this downward spiral is in choosing shoes that fit well – though they estimate that as few as one third of people with diabetes actually wear optimal fitting shoes. This may be because there is a strange temptation for people with diabetes to choose extra small shoes due to their neuropathy. When normal sensation is lost in the feet, tight fitting shoes actually feel better because they can be sensed more readily by the brain. So even though spacious shoes that don’t cramp the toes or cause blistering are the best footwear, they don’t always feel as comfortable. However, patients with diabetes who are properly fitted for orthopedic shoes with the help of a physiatrist or podiatrist, may substantially reduce their risk of ulcers.
So the bottom line for people with diabetes: choose your footwear carefully, and get professional help to make sure that your shoes fit well. Proper shoes could help to decrease your risk for foot and leg ulcers and potential amputations.This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
November 4th, 2007 by Dr. Val Jones in News
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Harvard researcher, Dr. George Church, is spearheading a project that would make complete personal genome mapping available for a mere $1000. I read his research subject recruitment disclaimer. Here is a choice excerpt:
Volunteers should be aware of the ways in which knowledge of their genome and phenotype might be used against them. For example, in principle, anyone with sufficient knowledge could take a volunteer’s genome and/or open medical records and use them to (1) infer paternity or other features of the volunteer’s genealogy, (2) claim statistical evidence that could affect employment or insurance for the volunteer, (3) claim relatedness of the volunteer to infamous villains, (4) make synthetic DNA corresponding to the volunteer and plant it at a crime scene, (5) revelation of disease lacking a current cure.
I wonder what personal genome mapping means from an ethical and legal perspective? Are we equipped to handle the possible privacy violations and prejudice inspired by DNA coded predispositions? On the one hand, customizing medical treatment to a person’s genes offers some of the best hope for optimal care and cures. On the other hand, having your genes on public display could put you at risk for the five problems described by Dr. Church.
These are exciting and frightening times.This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
