Contrast-enhanced ultrasound utilization on the rise

March 15, 2021
by Lauren Dubinsky, Senior Reporter
It’s a frightening enough experience for pediatric patients to undergo medical procedures, but having to face large, noisy machines like MR and CT scanners can significantly compound that fear. Fortunately, contrast-enhanced ultrasound (CEUS) is now a viable alternative.

Dr. Susan Back
“The ultrasound examination environment and equipment are pediatric friendly,” explained Dr. Susan Back, chair of the Society for Pediatric Radiology (SPR) CEUS Task Force. “Children can remain in close contact with caregivers, can be examined in a variety of positions and the ultrasound unit is not as imposing as CT, MR or fluoroscopic towers.”

Similar to ultrasound exams, the vast majority of children don’t require sedation or anesthetics to undergo this procedure and no radiation is involved. There is also an added benefit for critically ill or immobile pediatric patients, as CEUS can be performed at their bedside in the intensive care unit or emergency department.

But despite its long list of benefits, a dark cloud still looms over this medical advancement.

The “black box” controversy
Historically, there has been concern over the safety of ultrasound contrast agents (UCA). The FDA put a black box warning on UCAs in 2007 following reports of four deaths and 190 serious cardiopulmonary reactions in adults.

However, Back assures that there is nothing to worry about. Even though those adverse events were temporarily related to these exams, they were “not clearly a result” of UCAs, she said.

Since those initial reports, millions of UCA injections have been administered safely. There is a growing body of literature outlining the safety profile of these agents and benefits of these studies in children and adults.

Armed with this data, the SPR CEUS Task Force supported the Citizen’s Petition filed by the International Contrast Ultrasound Society (ICUS) to remove the boxed warning in March 2019. Various medical societies also supported this petition including the American Institute of Ultrasound in Medicine (AIUM) and the Society of Radiologists in Ultrasound (SRU).

“It is clear to all who work in the field on a daily basis that the black box harms patient care by misrepresenting risk and inappropriately deterring the use of UCAs when they are medically indicated,” said Dr. Steven Feinstein, co-president of ICUS and professor of medicine at Rush University Medical Center in Chicago, in a statement.

According to the Petition, the black box warning has led to the reluctance of some physicians to refer patients for CEUS, and some patients are apprehensive about receiving UCAs. The warning is intended to be an indicator of the very highest-level risk associated with FDA-approved products.

Since 2007, the FDA has downgraded package insert contraindications three times and removed a 30-minute monitoring requirement for patients with pulmonary hypertension or unstable cardiopulmonary conditions. Additionally, the agency has recently approved new indications for use in adults and children.

The major potential adverse reaction associated with UCAs is anaphylaxis, but it’s rare and occurs at a similar or less common rate than this type of reaction to gadolinium agents, according to Back.

“UCAs are primarily cleared from the body through the lungs and do not deposit in the body or burden the kidneys or liver,” she added. “Therefore, renal function does not need to be checked prior to the examination and they can be used in people with compromised renal function as well as those with renal transplants.”

Adoption is on the rise
For more than 40 years CEUS has been in clinical use, although mostly outside of the U.S. until recently. Thanks to continuous advancements in ultrasound technology and UCAs, many radiology practices in the U.S. are now adopting CEUS.

“There are very active national and international basic science and clinical research communities,” said Back. “CEUS studies are routinely presented at major radiology scientific meetings and are published in journals.”

A special issue on CEUS is set to be published soon in the SPR’s official journal, Pediatric Radiology. In addition, both adult and pediatric CEUS courses are currently available, and some educational programs have been added to imaging society meetings.

The lack of appropriate current procedural terminology (CPT) codes has been a hurdle to widespread adoption in the U.S., but things are starting to change. A new “Category I” CPT code for the use of CEUS for non-cardiac abdominal imaging went into effect on January 1, 2019.

Also in 2019, two new CEUS CPT codes were created by the Centers for Medicare and Medicaid Services (CMS). The 76X0X code is for a stand-alone procedure for the evaluation of a single target lesion and the 76X1X code is an add-on for the evaluation of each additional lesion

ICUS keeps abreast with CPT code developments and has compiled all current information, which is available for free on its website.