ARDMS NewsWire February 4, 2011‏

Contrast-Enhanced Ultrasound (CEUS) Improves Diagnosis Of Medical Conditions In Children
New research released shows that "contrast-enhanced ultrasound" (CEUS) can safely improve the diagnosis of a variety of medical conditions in children - without exposing them to ionizing radiation.

Dr. Martin Stenzel, a pediatric radiologist at the University Hospital in Jena, Germany, reported that no adverse safety event was found when CEUS was used to image some 50 pediatric patients at his hospital.

Stenzel presented his findings at the 16th European Symposium on Ultrasound Contrast Imaging in Rotterdam.

"Our experience shows that this technology works in children as well as adults," Stenzel said. The youngest patient Stenzel and his colleagues examined with CEUS, was two years old, he said.

Unlike CT and nuclear imaging, ultrasound scans do not expose patients to ionizing radiation - which is associated with an increased lifetime risk of cancer, according to Stenzel.

"It is especially important to avoid subjecting children to diagnostic tests that use ionizing radiation because children have many years to live and the risk of cancer is cumulative," Stenzel said. "In addition, we do not know how ionizing radiation may affect future reproductive capacity or the impact it may have on their unborn children."

Stenzel said that since CEUS images are not jeopardized by patient movement, the technique is particularly suitable for imaging young patients who will not lay still. "This avoids the need for sedating children prior to imaging," he said.

Stenzel said he and his colleagues have used CEUS to differentiate between a benign cyst and a perfused tumor, which could be quite dangerous and require immediate treatment. This helps avoid invasive tissue sampling, which presents additional risks and can be more difficult in children than in adults.

According to Stenzel, severe forms of kidney infections can be assessed more accurately with CEUS, which can help physicians detect tiny abscesses or pus formation that would require stronger antibotic treatment.

In addition, Stenzel said CEUS is "especially helpful" in evaluating an organ's blood flow, or perfusion. "Bowel and testicular torsion, or twisting -- typical diseases of the younger child -- are medical emergencies in which confident ultrasound results will prevent unnecessary surgical explorations," he said.

He also said that CEUS was extremely useful in detecting internal abdominal injuries caused by a fall during play.

According to Stenzel, CEUS is safe, accurate, and less expensive than alternative imaging techniques. He called for additional clinical trials to validate the use of CEUS in pediatric patients.

Conventional ultrasound is a first-line imaging tool used to diagnose a wide variety of medical conditions throughout the body.

Ultrasound "contrast agents" may be used during an ultrasound examination to improve the clarity and accuracy of a conventional ultrasound image. They consist of suspensions of biocompatible and biodegradable microbubbles that are smaller than red blood cells. Unlike contrast agents used in MRI and angiography procedures, ultrasound contrast agents do not contain dye - which may produce allergic reactions in some patients.

After an ultrasound contrast agent is injected into a patient's arm vein, it flows through the circulatory system, mimicking the flow patterns of red blood cells while reflecting ultrasound signals. An ultrasound probe placed over a region of interest, such as the abdomen or heart, will pick up the reflected signals and transmit them to a moving, real-time image of the target organ system. A few minutes after injection, the contrast agent is essentially breathed out of the body.

Ultrasound contrast agents have been approved for use in adult patients only. Their use in children is off-label and requires informed consent, according to Stenzel.

CEUS is used in the United States to improve certain forms of cardiac imaging, and in Europe, Canada, Asia and Brazil for evaluating medical conditions throughout the body - including the heart, liver, brain, digestive tract and kidneys.

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Article written by staff at medicalnewstoday.com and adapted for the purposes of this newsletter.

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New Stroke Guidelines Weigh Stenting vs. Endartectomy, Ultrasound Screening
Widespread screening with ultrasound for carotid stenosis to determine stroke risk isn't necessary, and both carotid stenting and carotid endarterectomy are safe and effective methods to treat the condition, according to new guidelines on the management of patients with extracranial carotid and vertebral artery disease from the American Heart Association/American Stroke Association (AHA/ASA), the American College of Cardiology (ACC), along with many other associations.

"In general, people are gaining an awareness that atherosclerosis is a systemic disease that extends beyond patients who experience heart attacks, along with the disease complications including stroke," Jonathan L. Halperin, MD, director of cardiology clinical services at the Zena and Michael A. Wiener Cardiovascular Institute at Mount Sinai Medical Center in New York City, explained. "Also, these guidelines are particularly timely because an FDA committee recommended broadening the indications for carotid stenting, which heretofore were either used in research trials or those patients who were deemed inoperable candidates.

"Prior to these guidelines, there weren't any widely accepted standards about when ultrasound assessment should occur, but we determined that it should be a part of routine screening, but reserved for patients with known disease that needs [assessment or presents with] clinical reason to be highly suspicious," offered Halperin, co-chair of the writing committee.

Some examples when ultrasound should be employed, according to the authors, are if a physician hears carotid bruit (abnormal sound in the neck that could indicate turbulent blood flow in the neck arteries), or if a patient has two or more risk factors for stroke, such as high cholesterol or a family history. Other stroke risk factors include age, family history of stroke, high blood pressure, high blood cholesterol, diabetes, obesity, atrial fibrillation, physical inactivity, sickle cell disease and other heart or blood vessel diseases.

Among dozens of recommendations, the writing committee concluded that the two often competing procedures-carotid stenting and carotid endartectomy-are both "reasonable and safe" when arteries are more than 50 percent blocked.

The guidelines took into account the two recent large-scale, randomized trials: CREST in the U.S. and the International Carotid Stenting Study. Because the two trials arrived at "slightly different conclusions," Halperin said, the committee had to truly assess the strengths and weaknesses of both trial designs.

"The guidelines support catorid surgery as a tried-and-true treatment for most patients," said Thomas G Brott, MD, committee co-chair and professor of neurology and director of research at the Mayo Clinic in Jacksonville, Fla. "However, for patients who have a strong preference for less invasive treatments, carotid stenting offers a safe alternative. Because of the anatomy of their arteries or other individual considerations, some patients may be more appropriate for surgery and others for stenting."

Also, Halperin stressed while both techniques may be viable options for many patients, operator experience is integral for success with either technique.

Finally, "all patients should be receiving optimal medical therapy whether they receive revascularization or not." Medications offer a better alternative than either surgery or stenting for many patients, according to the guidelines. Based on the latest clinical trials comparing the procedures, all patients received optimal medical treatment but there were no medication-only groups.

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Article written by staff at cardiovascularbusinnes.com and adapted for the purposes of this newsletter.

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Turf Battles Brewing Over Lung Cancer

A turf war is brewing over new technologies being explored for lung cancer diagnosis and treatment -- potentially setting up thoracic surgeons for battles on multiple fronts, experts warned.

The use of robotic surgery, endobronchial ultrasound, and CT lung cancer screening appear to be seeding conflicts likely to blossom in coming years, according to a panel at the technology-focused Tech-Con portion of the Society of Thoracic Surgery conference here.

The infamous incursion of interventional cardiologists into the traditional surgical terrain of revascularization, with stenting taking over a large proportion of the ground from coronary artery bypass surgery, has been on the minds of many conference attendees, noted Kazuhiro Yasufuku, MD, PhD, of the University of Toronto and Toronto General Hospital.

"One of the questions is how to deal with the pulmonologists," he explained. Thoracic surgeons and pulmonologists have shared some of the same territory in diagnosing lung cancer, but changing technology could shift the balance, Yasufuku suggested.

CT lung cancer screening picks up more small, early-stage lung cancers than had been possible in the past, and the number of patients screened and new lesions found could rise dramatically now that the national CT screening trial has reported a 20 percent reduction in mortality from screening high risk patients, Yasufuku projected.

For staging tumors, fine-needle aspiration done with ultrasound-guided endoscopy can do just as well as the traditional, more invasive CT-guided biopsy -- and is safer for patients because there's no need for general anesthesia, he noted. Similar minimally-invasive strategies, such as ablation, to treat small lung tumors without radical resection or even lobectomy are under development.

"Thoracic surgeons need to have the skills to do these procedures because in the future I think we'll be treating very small tumors endoscopically without any surgery," Yasufuku said. "Unless you know how to approach these nodules with different kinds of instruments I think you're going to lose it to the pulmonologists." Recent years have seen the advent of interventional pulmonology as a new field, with programs now at a handful of U.S. centers.

"A lot of the rapid surgery centers now are starting to include the interventional pulmonologist speciality, and that's not a good idea," he told thoracic surgeons. There's room for both specialties, but thoracic surgeons need to learn the new techniques, he explained. Yasufuku suggested taking a proactive tack.

His group created the endoscopic equivalent of a catheterization suite -- what Yasufuku called the thoracic interventional suite of the future. That suite is outfitted for fluoroscopy, general anesthesia, and open thoracic surgeries -- and equipped with all manner of the newest technology:

High-end endoscopic technology
Flexible videobronchoscope
Rigid bronchoscope
Autofluorescence bronchoscope
Narrow band imaging
Endobronchial ultrasound with both radial and convex probes
Endoscopic ultrasound
Navigational systems
VATS equipment
Laser
High quality monitors
C-arm or equivalent device
Audio-video system
Getting all this technology into the hospital budget has been a challenge, but "I don't think we're going to lose everything to interventional pulmonology," he said, emphasizing collaboration instead of a takeover. The creation of a thoracic interventional suite is exciting, commented Scott Swanson, MD, of Brigham and Women's Hospital in Boston, in an interview prior to the conference.

"We're getting less and less invasive, which is good for patients and gets us to the disease earlier in its course," he said. One skirmish already playing out is the battle for time on robotic surgery equipment to do lobectomies, Brian E. Louie, MD, of Swedish Medical Center in Seattle, noted.

"It was hard," he agreed in response to a comment from the audience noting how difficult it can be to get robot time. "The gynecologists were putting on benign disease left, right, and center, and they booked those three to six weeks in advance; the urologists were using it five days a week from morning 'til late in the evening." Lung cancer patients needed to be fast-tracked for surgery, but faced limited time slots.

The solution at his institution, Louie explained, was that the thoracic surgeons successfully argued for a routine block of time kept open for lung cancer patients and another robot was added to ease the traffic.

But although use in lobectomy shows signs of expansion, it's been restricted so far by a lack of evidence that it is better than traditional surgery, Louie told attendees.

"At the current time," he said, "it is not better. The operative parameters and the outcomes are similar to VATS [video-assisted thoracoscopic surgery] lobectomy."