X-rays, CT scans and MRIs are helping doctors diagnose a wide variety of ailments. Interventional radiology can even target and treat cancer.
Medical imaging has come a long way since the basic X-ray procedures of 30 years ago. Today, doctors can use radiology to see inside the body in real time, diagnosing and treating a wide range of concerns, either as a precursor to surgery or avoiding surgery altogether.
"Over the past two decades, there has been a huge explosion in the technology," says Dr. Thomas Lombardi of Riverside Radiology and Interventional Associates. "X-ray was the old standby back in the '70s, but new technologies like CT and MRI are faster and have better resolution."
Computed tomography (CT) uses X-rays to create images resembling slices of the body. Magnetic resonance imaging (MRI) also creates highly detailed images, but uses magnetic fields instead of radiation.
Because there is such limitless detail in the human body, those who use imaging technology generally specialize in several areas, Lombardi says. Mammographers assess abnormalities in the breast, while other doctors specialize in musculoskeletal issues related to the joints and soft tissues. Neuroradiologists decode the mysteries of the central nervous system. Nuclear medicine specialists track radioactive isotopes injected into a patient, allowing them to see how the body functions and where problems are occurring. And interventional radiologists use imaging technology as a roadmap as they guide tiny tools to retrieve clots, deliver treatment and repair structural defects.
Dr. Richard White, chair of the department of radiology at the Ohio State University Wexner Medical Center, says the latter is especially valuable in the treatment of cancer. "Interventional radiology procedures allow us to treat the tumor instead of having to give chemotherapy and poison whole body," he says.
Physicians can use fluoroscopy to track a contrast agent that has been injected through a catheter, deliver chemotherapy drugs directly to the tumor, deliver radioactive beads or embolize nearby blood vessels to cut off a tumor's blood supply. "We go as far as possible past the normal tissues so we don't have to expose the whole patient and all of the normal tissue to chemotherapy," White says.
In certain cases, brain tumors spread over the surface of the brain, making surgical removal risky to impossible. Doctors can deliver treatment through the cerebral spinal fluid, using imaging to pinpoint the space between the vertebrae so they can insert a needle into the sac inside the spinal column.
In other cases, imaging guides doctors as they perform cryoablation or radiofrequency ablation on tumors in various parts of the body. "These procedures can shrink tumors prior to surgery, and give options to patients who otherwise wouldn't have options," White says.
Patients are typically awake but medicated for these outpatient procedures, and generally return home after a few hours.
Imaging is also helping the medical community understand not just the physical, but also the chemical and electrical pathways within the brain-the hub of communication for all bodily functions. White says tractography, or brain mapping, is an exciting field of study. "It creates a beautiful color-coded map of the nerves deep within the brain," he says. "A neurosurgeon can see the tumor and how it relates to the rest of the brain. It helps to see how the nerves flow down into the deep brain, and it gives an understanding of what we might be saving or sacrificing as we pursue therapy."
Riverside Radiology's Lombardi is a body imaging specialist who uses a variety of technologies in his daily work.
CT scans are useful for diagnosing abdominal pain, which is most typically caused by appendicitis, diverticulitis, kidney stones or gallstones. The technology can also be used to keep tabs on known malignancies to track how cancer is responding to treatment. The procedure is simple and getting more so all the time.
"Back in the '90s, it took five minutes, and now it takes seconds," Lombardi says. "The technology has evolved, but it uses the same basic principles and gives us a much better resolution."
Although it is an older technology, X-ray is still used frequently for assessment purposes. "The technology continues to get better and better in terms of lowering the dosage," he says. X-rays can be used to make initial diagnoses as well as to help doctors determine if more specialized tests should be ordered, such as a CT scan, MRI, biopsy or ultrasound.
During an MRI, magnetic energy pulses through the patient's body, Lombardi says. Doctors vary the frequency to excite protons within the body. The protons' response tells doctors what they're looking at. The test typically takes 20 to 50 minutes. MRIs are useful for identifying adrenal masses, a very common and benign condition. They can also be used to assess problems with joints, tendons and ligaments, and in cases of trauma.
Following a traumatic incident, surgeons used to put a needle into the abdomen, inject saline and withdraw fluid. If blood or stool was present, doctors knew a patient had internal injuries, but the technique was time-consuming and largely a guessing game. "Now we are able to get the patient treated much more quickly and accurately," Lombardi says.
An offshoot of the MRI is the MR-focused ultrasound, which can be used to ablate tumors. Right now, the technology is being used to treat uterine tumors, but it may have additional uses in the future, Lombardi says.
Aside from X-rays, patients are perhaps most familiar with mammography, since this type of radiological imaging is used even when there is no illness.
Dr. Daniel White is director of breast MRI at Mount Carmel Health System and medical director of both Mount Carmel East Imaging Center and Polaris Highfield MRI. He says mammograms typically utilize low-level X-rays, but can also employ ultrasound and MRI for a more accurate image. These additional tools can clear up confusion when questions arise with a mammogram. Although women may fear cancer when they get an abnormal result, a mass often ends up being a fluid-filled cyst or a benign fibroadenoma, a type of nodule.
Daniel White had a patient who got an abnormal result in her mammogram was scheduled to have three biopsies-two in one breast and one in the other. He went in with the intention of locating the areas to be biopsied, but discovered that none were necessary-all of the shadows that had appeared on the initial mammogram were due to benign conditions.
Women with a genetic predisposition to breast cancer are advised to maintain a more aggressive screening regimen. The American Cancer Society recommends that women with the BRCA gene mutation have both a traditional mammogram and an MRI every year. Daniel White says he recommends that patients stagger the tests every six months.
Breast imaging can prevent unnecessary surgery, but can also lead to unnecessary worry unless the results are read by an experienced specialist. "The quality of mammograms is something that can be pretty easily standardized," Daniel White says. "Mammograms at one hospital versus another are very similar. But MRI has an awful lot of technical components to it, and the way you do the test strongly influences the outcome."
He recommends working with radiologists who have both high sensitivity and high specificity ratings-a measure of how often they find cancer, and of how often their assessments are correct. He also advises patients to get an MRI-an electronic second opinion-before undergoing a lumpectomy.
Some of the most groundbreaking local research in imaging technology and treatments is happening at Nationwide Children's Hospital.
"We do everything in radiology except mammography," says Dr. William Shiels, the hospital's chief of radiology. "We provide both diagnostic and interventional radiology, from the tiniest one pound or less babies to adults who are treated best with techniques found at Children's."
Patients come from across the country and around the world to seek treatment for bone cancer, using a procedure developed at Nationwide Children's.
The hospital also routinely treats aneurysmal bone cysts, which can affect any bone in the body. While they are not cancerous, they grow until the bone fractures. If it happens in the shoulder, the arm becomes permanently useless. In the spine, a cyst could cause quadriplegia. Now, instead of cutting out major sections of bone, doctors are stopping the cysts before they grow.
"Instead of having a major surgical procedure, we are using very targeted, needle-based techniques to kill the tumor," Shiels says. Imaging is used to direct a needle to the site of the cyst, where the drug doxycycline-an antibiotic typically used for treating staph infections and acne-is introduced.
"You need to navigate to the right part," Shiels says. "We are putting a needle into a target no bigger than a quarter of an inch in diameter, and leaving a scar no bigger than a freckle. That requires precision." Doctors use a navigation system that may involve ultrasound, fluoroscopy, MRI and CT scan while working around delicate structures. "The unique strength of interventional radiation radiology? is that we can avoid damaging things like the carotid artery," Shiels says.
Treating an aneurysmal bone cyst takes an hour or two, and within six to eight weeks, the body will largely reabsorb the abnormal cells attacked by the antibiotic.
"The antibiotic kills the tumor and stimulates healing," Shiels says. From young children to people in their 30s and beyond, two to five patients per week seek treatment for aneurysmal bone cysts at Children's, Shiels says.
Training & Techniques
To train surgeons in new techniques, Shiels and his team employ some unusual hands-on tactics. The hospital's simulation training system involves everyday objects that mimic the feel and response of human body parts.
Using turkey breasts to simulate flesh, doctors use fluoroscopy, MRI and other tools to navigate around skin, bone and muscle. Shiels says they use everything from gel models to baby food (pus), salmon caviar (lymphatic malformations) and chicken liver (cancerous tumors). "A martini olive is a perfect simulator for breast cancer, and a cocktail onion has stripes just like a tumor," Shiels says. "They have to know how to get to it safely and treat it properly. Part of success is understanding why failure occurs."
Practice makes perfect, and many procedures require an extremely delicate touch, whether the patient is a child or adult. For that reason, radiology has become an essential part of everyday medical treatment.
Among the most delicate structures in the human body is the eye. Lymphatic malformations in the eye socket, also known as eye masses, occur when the blood vessels behind the eye fill with blood and other fluids. The condition puts pressure on the eye and can push the eye out of the socket. Affected patients cannot lead normal lives, and until recently, the only treatment was perhaps even more frightening than the condition itself.
"Surgeons don't have any good techniques," Shiels says. The eye socket is shaped like a funnel, with nerves running from the eye to the back of the funnel. Surgeons had to get behind the eyeball without hitting the nerves and deliver targeted treatment, with only about a quarter-inch to work with on either side.
"You had to lift up the brain and take the bone out of the top of the eye socket," Shiels says. "You do your best to put everything back and pray that it doesn't recur." The problem was, it often did. But with new treatments, interventional radiologists can guide the tiniest of needles into the eye area, bathe the affected cells with doxycycline and solve the problem for good. No cutting or suturing is necessary.
Shiels treated a boy-now 13-who suffered from eye masses. He couldn't go to school or play sports. Periodically, his heart rate would drop dangerously low as a result of the pressure in his eye, and overnight, his eye would pop out of its socket. He risked blindness and suffered for 10 years while doctors tried repeatedly to treat the condition. Today, he plays basketball, runs track and enjoys athletics with enough vigor that he broke his leg playing sports.
"It totally changed things for him," Shiels says. "He has a life he never had before."
Kristin Campbell is a freelance writer.