The Greeks considered the liver to be the home of all human emotions and the organ closet to divine presence. Today, we look at the liver more practically. It is the largest organ in our body, and protects the rest of the human body from harmful substances and toxins.
A healthy liver is crucial to overall health. Yet approximately 30 million people in the U.S. have some form of liver disease – though it’s difficult to diagnose as its symptoms can be vague and easily confused with other health issues.
Medical imaging tests, such as magnetic resonance, computed tomography and ultrasound, are typically used to diagnose liver disease. In April 2016, the FDA approved the use of contrast agent for liver lesion characterization – offering clinicians a fast, radiation-free way of confidently detecting problems in a patient’s liver.
We asked two experts in liver ultrasound imaging for their take on why this development is so important for health care, and patients around the world. Dr. Beth McCarville, MD is Chief of the Body Imaging Section at St. Jude Children’s Research Hospital in Memphis, Tennessee. And Dr. Hisham Tchelepi, MD is Chief of Ultrasound for both diagnostic and interventional purposes at Keck Hospital of University of Southern California.
What differences and improvements have you seen with contrast enhanced ultrasound (CEUS)?
Dr. McCarville: Our main clinical indication for CEUS is to characterize focal liver lesions. Focal liver lesions occur in about 17% of children after cancer therapy. When such lesions arise, it is crucial to determine whether they are benign or represent metastatic disease. Before utilizing CEUS at our institution, such patients would undergo additional imaging (often MRI which can require sedation of young patients) or early imaging follow-up to determine the growth rate of the lesion. This approach resulted in added time, cost and anxiety in the patient’s management.
Now these patients undergo CEUS on the same day or the next day after the original imaging exam that discovered the focal liver lesion. This approach is quick, low-cost, radiation and sedation-free and provides immediate feedback to the patient, their family, and treating physician.
Dr. Tchelepi: One of the biggest advantages is that ultrasound is not as time-consuming as some of the other procedures like magnetic resonance imaging, and we don’t need to expose the patients to any radiation as we would with a computed tomography scan. In addition, there’s often no need for additional referrals, which can take time, cost money, and cause unnecessary stress.
In our practice, we managed to solve problems in 68% of the cases with no need for further CT, MR, or additional referral. It also saves the patient an incredible amount of time as we can address their issues and concerns in a single day. The actual procedure between the point of injection and when the image appears only lasts 10 minutes.
How do you think CEUS will be used one year from now?
Dr. McCarville: I believe the role of CEUS in pediatric oncology will increase. There are a wide variety of potential applications. In addition to being low-cost and radiation and sedation free, it has the added benefit of being portable. This is an important attribute in our institution because patients needing imaging studies may be too ill to come to the radiology department.
Five years from now? With the introduction of targeted therapies into cancer clinical trials, there is a growing need for functional and metabolic imaging methods that go beyond a simple measurement of tumor size. Dynamic, quantitative CEUS may provide a method of assessing tumor blood flow which, in turn, may reflect or predict response to therapy. This, however, needs to be validated in clinical trials.
Dr. Tchelepi: Ultrasound with contrast will make a big leap in the coming years – particularly when you look at the key advantages over other procedures: lower cost and less time. With FDA approval, I also think that ultrasound with contrast will go far beyond the liver.