by Lisa Hanchey

Radiology is not just about plain x-rays anymore. Today's radiologists use the latest technology to analyze not only still pictures, but moving organs. Modern equipment has evolved far beyond two-dimensional to 3D and even 4D views.

Currently, radiology involves not only interpreting films, but also preventing and treating disease. Interventional radiologists are constantly finding less invasive methods to cure conditions through technology, rather than surgery. This month, Acadiana Medical News surveys some of the latest diagnostic advances, as well as the newest interventional and radiology techniques.



Cutting-edge Diagnostic Technology

Area radiologists agree that the most exciting diagnostic advances are in multi-slice computed tomography, positron emission tomography and short-bore magnetic resonance imaging. Of course, CT, PET and MRI have been around for a while, but constantly evolving technology is taking these scans to a whole new level.

For CT, the current trend in radiology is moving from four-slice to 16- and 64-slice scanners. A decade ago, the CT was a tedious process, scanning one cross-section of the body at a time. "For example, you would take a scan slice, the table would move, you would take another scan slice, the table would move," explains radiologist Charles Brdlik, who practices with the Radiology Associates of Southwest Louisiana. "Nowadays, what we're doing is using the helical multi-slice scanners to basically obtain a volume of information on the patient at one time."

Obviously, the old scans were extremely time-consuming. By contrast, today's 64-slice scanner is lightning-fast. "Ten years ago, with the single-slice helical scan, you may have been doing a CT of the abdomen and acquiring the information in two or three minutes, and then you'd have to reconstruct it again, and that might take you another 10 to 15 minutes," Brdlik says. "With the 64-slice scanner, you can probably do the entire body from the top of the head down through the toes in less than a minute."

This new, high-speed technology is so advanced that it allows radiologists to obtain images on moving, as well as stationary, structures. For instance, doctors can view a beating heart or a scan a restless infant. "The 64-slice CT overcomes motion as a detrimental factor in maintaining spatial resolution," explains Dr. Joseph B. Prejean, a diagnostic radiologist with Lafayette Radiology Associated. "For example, it allows us to look at infants, who would ordinarily have to be sedated, because it's just a matter of seconds before we can complete the examination. It allows us to look at moving physiologic structures, like the heart, without loss of anatomic detail. And, it even allows us to do coronary angiography."

The latest advance in CT technology is the PET/CT scan, which combines PET - a type of nuclear medicine study - with CT. This machine offers great promise for pinpointing cancerous tumors. The combo-scan provides a faster and more accurate study than its separate components. "One of the disadvantages of CT is that we can see structures, but we don't know if they might represent cancer," Prejean says. "PET, on the other hand, allows us to make a determination whether or not a certain anatomic abnormality might be related to cancer. The problem, though, is that PET has good contrast resolution, but does not have good spatial resolution. CT, on the other hand, has good anatomic or spatial resolution, but does not give you contrast resolution as well as PET in regard to tumors. And so, using the combination allows us to get the best of both."

New MRI scanners also allow radiologists to better diagnose cancerous tumors. Siemens Medical Solutions recently developed a system capable of 3 Tesla whole-body MRI, which "has the potential of allowing us to scan whole bodies, for example, in patients who have cancer to screen for metastasis," Brdlik says.

Another advance with MRIs are short bore units, which offer more comfort for claustrophobic patients. "The MRI scanner is high-field and what they call open, but really is a very short bore closed unit that would have similar advantages as far as patients who have claustrophobia, yet still give us the excellent image quality that we get with the high-field 1.5 units," Brdlik says.



Interventional Radiology: The Latest Minimally Invasive Treatments

Using the newest technologies, interventional radiologists are able to obtain definitive diagnostic material or effect therapeutic results. This allows radiologists to treat conditions through less invasive means, such as with needles and catheters, which allows patients to avoid major surgeries. "The whole idea is that it's less invasive, and as a result, there are fewer complications to the patient," Prejean says. "Also, it's less costly, because many of these procedures can be done without a major operation, and can be done on an outpatient basis. So, that cuts back on the overall cost of managing a particular problem."

With a CT or PET scan, a radiologist can pinpoint potentially cancerous lesions. From there, using guidance from CT, ultrasound or fluoroscopy, the physician inserts needles inside the lesion to obtain definitive tissue for pathology. "By doing such, we prevent patients from having unnecessary additional procedures, such as endoscopy or surgery, to make that kind of diagnosis," Prejean explains. "It's cheaper, it's less expensive, and because many of these are outpatient procedures, a patient can have this biopsy done and go home in one hour."

Interventional radiologists can use this same advanced technology to drain abscesses so that patients do not have to resort to surgery. They can also provide venous access surfaces, such as through port catheters. "For example, with cancer patients, after so many rounds of chemotherapy, it is very difficult to find peripheral veins," Brdlik explains. "Instead of having to worry about that, you can just put a needle into the port itself, and you have automatically accessed the vein. So, it saves the patients a whole lot of pain and suffering of just trying to get the access to the veins."

Interventional radiology is becoming increasingly specialized. Lafayette has two interventional neuroradiologists who treat conditions of the brain, head, neck and spine. Dr. Joan Wojak, along with her partner, Dr. Buckley Terpenning, are among only a handful of these highly specialized practitioners in this state.

Interventional neuroradiologists specialize in tackling complex conditions, such as aneurysms and strokes, from within the blood vessels. By working endovascularly, these physicians can administer treatment through minimally invasive catheters, rather than resorting to major brain surgery.

For treating aneurysms, the newest technique involves inserting soft platinum coils with bioactive coatings through a catheter. The coatings on the coils are specifically designed to fill the particular type of aneurysm. "Some of them are designed to swell and take up space, so that they can fill the aneurysm quicker, or to fill a funny-shaped aneurysm that you couldn't otherwise fill," Wojak explains. "Others are designed to induce the formation of scar tissue to help fill up it, seal it off, and make it go away more quickly. So, this is the newest thing in aneurysms - the use of these coatings on these coils to improve the efficiency of the treatment."

Other advances on the horizon are balloons and stents for use in the head. Currently, interventional neuroradiologists use apparatus originally created for the heart, which do not exactly fit in the brain. "The blood vessels in the head are a lot more 'twisty and turny' and it's much more difficult to get a balloon or stent there than it is to get one to the heart," Wojak explains. "But now, we've got a balloon and a stent that have been specifically designed to overcome those issues."

Wojak was one of the physicians who helped to design the intracranial stent and balloon. Trials in Europe yielded "outstanding" results. She hopes that these specialized devices will be available in the United States later this year. "It's exciting to now have something that is specifically designed for us to use in the head," she gushes. "The procedure is now being recognized to the point where they've generated a billing code for it. This is all developing as we speak."

Already in use for stroke patients is the clot retriever, or the Merci device, which was just approved in August. This corkscrew-shaped apparatus imbeds itself into a blood clot, allowing a physician to remove the whole clot from the brain. For patients who are unresponsive to clot-busting drugs, this new procedure is just the ticket. "This was actually featured on 'ER' [the television show] about two months ago, where they treated a patient with it," Wojak says. "So, that's given us another tool in the treatment of acute strokes that we didn't have before, which is pretty exciting."



Radiation Oncology: Treating Cancer with the Most Advanced Technology Available

In Acadiana, where cancer is a major concern, radiation oncologists are already using the newest advances in treatment. One of the latest technologies is intensity-modulated radiation therapy (IMRT), which allows administration of higher doses of radiation to the tumor, with significant reduction of doses received by surrounding, normal organs.

"IMRT allows isodoses to curve around and spare the uninvolved organs while at the same time delivering a full dose of radiation to the cancerous tissue," explains radiation oncologist Julian Krawczyk of Oncologics, Inc. "The isodoses on the radiotherapy plan are the lines with the same dose of radiation, resembling the lines with the same temperature we observe watching the daily weather forecast."

Another advance is with stereotactic radiation, or radiosurgery. For years, this method of using one big dose of radiation, as opposed to several treatments, has been used to target benign and malignant brain tumors. Now, this technique is moving outside of the brain to the rest of the body. The extracranial radiosurgery has been rarely used, most in the academic and research setting. However, Dr. Krawczyk says that this modality should be commercially available "pretty soon."

Brachytherapy, which is another form of radiation, has been around for a long time. But recently, its use has increased in several areas, particularly breast cancer. Typically, breast cancer is treated by mastectomy or lumpectomy. Following lumpectomy, whole breast external-beam radiation is usually required for six or seven weeks. With brachytherapy, in highly selected cases, the treatment time may be dramatically reduced to only five days.

A new brachytherapy technique involves MammoSite, which is a small balloon containing a radioactive source that is inserted into the lumpectomy cavity during surgery. Radiation is then delivered to the balloon-filled area for five days. After the requisite period, the MammoSite is removed through a minor outpatient procedure. "The MammoSite, or any other brachytherapy form of treatment, may replace the whole breast radiation, which is cosmetically better, may be cheaper, and definitely shorter - it takes five days, not six or seven weeks," Krawczyk confirms. A product similar to MammoSite, called GliaSite, is now available for treating brain tumors.

With the increasing use of chemotherapy, the role of radiotherapy has been evolving over the last several years. "The concomitant use of both modalities brings cooperation between radiation and medical oncology to a new, higher level, ultimately resulting in better cooperation, safer and more efficacious treatment benefiting a large number of patients in our community."