The Medical Research Council (MRC)
supports continuing research and fosters investigations that face the medical challenges and health needs of today's world.  MRC programs focus on current research at HMRI, featuring laboratory scientists and physicians, to inform our Life, Benefactor and Associate members of the Council and their guests.

For information about membership and events call (626) 5804.

MR: The Next Decade

Since HMRI opened its Magnetic Resonance Laboratory in 1983 as the first unit in the U.S. to operate in both research and clinical capacities, it has enjoyed an enviable reputation for excellence and productivity among radiologists and others in the medical world — training physicians and technicians through fellowship programs and seminars, initiating teleradiology links with medical centers across the country and throughout the world, publishing landmark studies that reinforced MRI's usefulness in imaging soft tissues, sending distinguished lecturers to professional meetings in all parts of the globe, and continuously developing new refinements to increase the system's sensitivity and diagnostic capabilities,.

The laboratory was conceived by neurosurgeon C. Hunter Shelden, M.D., and HMRI Executive Director William Opel, Ph.D., at a 1980 Cell Biology Meeting in Berlin, long before the medical community was generally aware of NMR (Nuclear Magnetic Resonance, as MRI was then called). It drew upon the clinical resources of Huntington Hospital and scientific resources at Caltech, plus generous financial commitments from donors, and soon became the world's busiest clinical MR scanner, under the direction of William G. Bradley, M.D., Ph.D., who continues to be one of the world's leading experts in MRI and is currently Professor and Chairman, Department of Radiology at UC San Diego. He has authored more than 160 articles and 18 books, including the major MRI textbook Magnetic Resonance Imaging, which was first published while he was at HMRI.

MR Spectroscopy soon followed MR Imaging at HMRI, with the arrival in 1988 of Brian D. Ross, M.D., D. Phil., from Oxford University, one of the few physicians at that time to have studied important diseases in a great number of patients using MRS. [Like MR Imaging, MRS uses magnetic fields and radio waves to "tune in," or resonate, to chemical elements in the body; but in the case of spectroscopy the product is a spectral graph of chemicals rather than an anatomical picture. Individual chemical species can be identified and measured in the body, allowing detailed studies of the metabolism of the brain, heart, prostate, kidney, liver, colon, and in tumors — a living biochemistry of the human body. It enables diagnosis and allows the monitoring of treatment in many diseases. ] Soon, pioneering MRS studies emerged from HMRI, the radiology community was instructed as to its clinical applications, and local clinicians welcomed it as a valuable tool for helping their patients. The MRS Laboratory enjoys an international reputation for its continuing contributions to the science and application of MR technology, under the direction of Dr. Ross.

At a recent gathering of the HMRI Medical Research Council, Dr. Bradley presented an overview of MRI, its past, present and future, following introductions by Dr. Opel and Dr. Ross. "When we first started working with MRI we were not sure it would fly," Ross said. "Bill Bradley turned a marginally workable first-generation MRI scanner into a reliable diagnostic resource." His work translated nuclear magnetic resonance, previously used only in chemistry laboratories, into technology that could create images of body tissues with clarity never seen before. A Bradley paper in 1984 showed that MRI outperformed CT in the quality of its images. "That was the start of Bill Bradley's career, which has been a combination of brilliant science and brilliant medicine."

When Ross visited HMRI in 1984, he said, "I found Bill had recruited a brilliant team of technologists and scientists who, with no training other than what he had given them, were producing dozens of images a day. I had come from a clinic that was only able to see one MRI patient each week! Bill Bradley educated a whole generation of American radiologists. He turned a sleepy branch of his profession, complacent in the 100-year-old technologies of the x-ray, into an intellectual pursuit most sought by the cream of US medical school graduates."

Citing Bradley's contributions to imaging, Ross noted that he has developed innovative MRI protocols, translating the complex signals coaxed from the body's tissues into meaningful biological indices relevant to function and dysfunction. His primary research has been on the use of MRI in the brain, concentrating on stroke, hemorrhage, multiple sclerosis, and tumor characterization and improved resection using intra-operative MRI. His work on normal pressure hydrocephalus, one of the few treatable causes of dementia, has shed light on both its etiology and diagnosis.

Dr. Bradley talked about the value of MRI to modern medicine and explained the MRI process. "MRI is an advanced medical diagnostic technique that allows a physician to see inside the human body, with very clear images of the soft tissue like muscle, fat and the internal organs, without the use of x-rays or CT scanning. It is the premier imaging modality today," he said, "over CT or PET or ultrasound." The MR image is not a photograph. It is actually a computerized map or image of radio signals emitted by the body. It can generate thin-section images of any part of the human body, from any angle or direction.

In conjunction with radio wave pulses of energy, the MRI scanner can pick out a very small point inside the body and ask it: "What kind of tissue are you?" The point might be a cube that is half a millimeter on each side. The MRI system goes through the body point by point, building a 2-D or 3-D map of tissue types. It then integrates all of this information together to create 2-D images or 3-D models.

Bradley made some short-term predictions, some of which he was confident would soon have an effect at HMRI. These included the use of stronger magnetic fields, increased comfort for patients, the ability to image more tissues and to diagnose many more specific diseases. He also offered long-term speculations ­ about the possible use of hand-held MRI, and the use of MRI during surgery.

The biggest and most important component in the MRI system is the magnet, which is rated using a unit of measure known as a Tesla. The stronger the magnetic field, the stronger the amount of radio signals that can be elicited from the body's atoms and therefore the higher the quality of MRI images. Dr. Bradley is confident that field strength will continue to increase to improve the detail of images and acquire them faster. In the last 20 years, 'high field' has been 1.5 Tesla. Today, 3 Tesla is the new standard.

"The premiere research system will be 7 Tesla," he noted. "Not every institution is going to get one, as they cost about $10 million. The magnetic shielding for a 7T magnet is 100 tons of iron ­ a million dollars just for that. The magnetic field is so strong that a 747 dips as it passes over," he joked.

He predicts that the hole in the distinctive donut-shaped MRI tube, where the patient lies during image capture, will get shorter ­ a possible relief to claustrophobic patients - and that programming improvements will correct for small amounts of movement by patients, so that an MRI scan will not require a sedative to help the patient hold still.

Remarkable new images: blood vessels, joints, breast and brain

Bradley showed many remarkable MR images such as the vascular system in the legs. He explained that increased clarity is obtained partly because of a new contrast agent that goes in the blood to help show off the structure of the veins, arteries and capillaries. Most imaging modalities use injected contrast, or dyes, for the procedure. In MRI, the contrast works by altering the local magnetic field in the tissue being examined. Normal and abnormal tissue respond differently to this slight alteration, giving off different signals. These varied signals are transferred to images, allowing the physician to visualize many different types of tissue abnormalities and disease processes better than he could without the contrast.

Advances in MR technology will also improve signals from some solid tissues such as the knee, he said, where it may be possible to see the early stages of arthritis in deep-layer cartilage. "That will probably transform MR as much as earlier techniques did. We've never been able to see that before, which is significant because it is where a lot of arthritis starts. If you're going to test out a new drug for arthritis, that's how you're going to want to follow it," Bradley says.

Similar benefits in the treatment of breast cancer arise from better clarity at the 3T level. For one thing, the higher power of MRI at 3T means that a tumor that looks smooth and benign at low power may actually be rough-edged and malignant. With the higher power of 3T, there is a lot more detail to look at, resulting in a lot better diagnosis."3T is more expensive, but it gives the physician more choices: either higher quality imaging, or greater throughput. Patients can go through in one quarter of the time so they don't need to stay in the magnet as long. Back in 1983 when we started, it took us 17 minutes to acquire an image. At the time, they were the very best MRI images in the world. A higher-resolution image today can be done in less than three minutes."

Images from the brain are a major focus of MRI. Bradley mentioned many possible benefits that may come from 3T images: improved detection of MS, Alzheimer's, analysis and treatment of strokes, and brain trauma such as concussion.

Bradley was also enthusiastic that 3T MRI would be able to reduce the use of invasive angiograms. Right now, to analyze possible damage from a heart attack, doctors enter a major artery in the leg to slide a tiny camera up to the heart. "It's a little invasive. We can get comparable images and better spatial resolution (3-D perspective) in 10 minutes using a 3T magnet, without any groin puncture, versus conventional angiography. In the future we will only use groin-puncture angiography for treatment."

In another startling advance, he showed a scan of a brain specimen done at 7 Teslas ­ 100 microns of resolution. The image showed tiny islands of neurons, "which are the first thing to go in Alzheimer's disease," he said. "If we're going to find a new drug for Alzheimer's, we're going to have to find a non-invasive way of evaluating it. That's what we're going to get with 7T. This could be the 'killer application' for 7T."

The long view: MR in surgery

As for the longer-term predictions: Bradley thinks it will become more common to put MRI in the operating room. In a remarkable series of images, he showed that MRI could be used in surgery to assist in the removal of brain tumors. Doctors can produce an image of the brain prior to surgery to locate and diagnose a tumor. In surgery, a needle is inserted into the tumor to remove it, one small piece at a time. After the surgery, an MRI scan can check that the operation has fully removed the tumor. The MRI images also help make sure that no other parts of the brain are damaged.

MRI may also be used one day as a way to guide focused ultrasound in a process called ablation, or heating of a tumor, causing the tumor to die and be reabsorbed by the body. "It can be a way to attack brain tumors without cracking the skull," Bradley said. MR-guided focused ultrasound is a bit like using radiation. Because the energy is directed in the form of focused beams of ultrasound, the amount of heat deposited in the tumor can be controlled. The MRI scanner is able to see where the heat is applied. It is like a non-invasive scalpel and there is no cumulative toxicity, which can be a concern with radiation.

There will be many applications throughout the body including hysterectomies, operations on breast tumors, brain tumors — all without breaking the skin, Bradley predicts. "A critical term in surgery these days is 'minimally invasive'. We locate a tumor using MRI and perform a biopsy for a diagnosis using MR Spectroscopy. Then we eradicate the tumor with MR-guided focused ultrasound and never break the skin," he said. "The future of MRI seems limited only by our imagination. The technology developed at important research centers like HMRI is still in its infancy. Predicting the future of MRI is speculative at best, but I have no doubt it will be exciting for those of us in this field of medical research, and very beneficial to the patients we care for."

The Medical Research Council presents programs focused on current and emerging HMRI research projects. Underscoring the relevance of HMRI's research to urgent needs of patients, the symposia feature laboratory scientists teamed with leading physicians. Events are open to Life, Benefactor and Associate members of the Council and their guests.

For information about membership and future events please call (626) 397-5804.

Previous topics have included:

Alzheimer's Disease

Cardiac Metabolism

Neural Prosthesis for Bladder Control

Prostate Cancer

Parkinson's Disease

Magnetic Resonance: Imaging and Spectroscopy

Genetics of Breast Cancer

Hydrocephalus

Allergy

Electronic Control of Epilepsy

Implantable Hearing Electrodes

Neurosurgical Fellowship Program

Proteomics:  The Molecular Analysis of Disease

Head Trauma

Students:  The Future of Medical Science

Breast Cancer Detection and Evaluation

Heart Attack and Automated Emergency Defibrillator

Volunteers in Clinical Trials

Rewiring the Brain to Treat Neurological Disorders

Hepatitis C

Investing in Tough Times

Images of the Heart - Cardiac MRI

New Approaches to Surgical Pain Management

The Aesthetics of Aging

Liver Center Dedication

MRI: The Next Ten Years

Liver and Drug Toxicity

Advances in Hip and Knee Replacement

Meeting the Challenge of Parkinson's Disease

Reinventing MRI Imaging: Better, Faster, Cheaper