Contrast-Enhanced Ultrasound Improves Diagnosis of Medical Conditions in Children

Dr. Martin Stenzel, a pediatric radiologist from the University Hospital Jena (Germany), reported that no adverse safety event was found when CEUS was used to image some 50 pediatric patients at his hospital. He presented his findings January 2011 at the 16th European Symposium on Ultrasound Contrast Imaging in Rotterdam, The Netherlands. The conference, which was cosponsored by the International Contrast Ultrasound Society (ICUS), featured the latest clinical and research developments in the CEUS field. "Our experience shows that this technology works in children as well as adults,” Dr. Stenzel said.

The youngest patient Dr. Stenzel and his colleagues examined with CEUS, was two years old, he said. Unlike computed tomography (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 Dr. 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,” he 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.”

According to Dr. Stenzel, 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. Dr. Stenzel also stated that 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 Dr. Stenzel, severe forms of kidney infections can be evaluated more accurately with CEUS, which can help physicians detect tiny abscesses or pus formation that would require stronger antibiotic treatment. Moreover, he noted that CEUS is "especially helpful” in evaluating an organ's blood flow (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.” Dr. Stenzel also reported that CEUS was extremely useful in detecting internal abdominal injuries caused by a fall during play.

According to Dr. 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. Traditional 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 Dr. Stenzel. CEUS is used in the United States to improve specific 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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University Hospital Jena