SonoInterview by Medscape: A Radiologist’s perspective on the topic of point-of-care Ultrasound

In case anyone out in the Sono world was wondering what friends we have out there in Radiology, include this guy on the list… someone who understands what is best for patient care, how bedside US can save lives, and how every specialty has the capability and patient population to help their patients through this tool.

Handheld Units Shift Ultrasonography From a Diagnostic to a Clinical Evaluation Tool, Broadening Its Appeal

John C. Hayes; Harvey Nisenbaum, MD

Posted: 06/25/2012

Editor’s Note:

As smaller and more capable handheld units become available, the role of ultrasonography in medicine is changing. Harvey Nisenbaum, MD, Associate Professor of Radiology at the University of Pennsylvania Perelman School of Medicine, captured key elements of those changes at the recent meeting of the American Institute of Ultrasound in Medicine (AIUM) in an address titled, “Perspectives on Point-of-Care Ultrasound: Matching the Need With the Technology to Understand How Ultrasound Is Migrating From a Diagnostic to a Clinical Evaluation Instrument.” In an interview with Medscape, Dr. Nisenbaum describes some of the implications of that shift for radiology and other specialties that are increasingly adopting ultrasonography as a clinical tool.

Medscape: Thank you for joining us, Dr. Nisenbaum. Will you please explain why and how ultrasonography is migrating from a diagnostic modality to a clinical evaluation instrument? How do you distinguish between the 2 uses?

Dr. Nisenbaum: Point-of-care (POC) ultrasound is the use of ultrasound by the healthcare provider at the time of physical evaluation of a patient or performance of a procedure on a patient. The traditional diagnostic use of ultrasound is when the healthcare provider sees a patient with a clinical problem and sends that patient to another location for an ultrasound study to identify the cause of the patient’s symptoms. For example, a pregnant patient with vaginal bleeding is sent for ultrasound evaluation of the pregnancy, or a patient with right upper-quadrant pain is referred for right upper-quadrant ultrasound.

Medscape: What are some other examples of the uses of ultrasonography?

Harvey Nisenbaum, MD

Dr. Nisenbaum: The traditional use of ultrasound is by such departments as cardiology, obstetrics and gynecology (ob/gyn), radiology, surgery, or urology. These departments will use ultrasound to look at the anatomic areas that are pertinent to their specialty. For example, the ob/gyn department will use ultrasound to evaluate clinical questions in pregnancy and gynecology. In cardiology, it will be used to evaluate the structure and function of the heart. In radiology, we will use ultrasound to evaluate various areas, depending on the clinical question asked by the healthcare provider who is referring the patient.

In the POC environment, ultrasound will be used by the healthcare provider at the time they are evaluating the patient or performing a procedure. The emergency medicine department will use it when they are evaluating the patient or performing a procedure. Anesthesiologists may use ultrasound for guidance for nerve blocks. In the critical care environment, it will be used in the intensive care units to evaluate the status of the patient — for example, how the heart is functioning and how the lungs appear. Musculoskeletal (MSK) ultrasound is used by orthopedists, rheumatologists, and podiatrics to evaluate their patient’s MSK complaints and, If necessary, for aspiration or injection of medication.

Medscape: Which specialties are most commonly using POC ultrasonography?

Dr. Nisenbaum: When you look at the applications, POC ultrasound is used by many specialties — including, but not limited to, anesthesia, critical care, emergency medicine, gastroenterology, interventional radiology, MSK, and even veterinary medicine. However, if you are talking about traditional use, the 3 main departments are radiology, ob/gyn, and cardiology.

Medscape: How has POC ultrasonography improved the quality of care?

Dr. Nisenbaum: In the critical care, emergency medicine, or trauma setting, ultrasound has been shown to be life-saving. For example, if a “fast scan” performed on a trauma patient shows fluid in the abdomen, the patient will go right to the operating room if he or she is unstable. If the patient is stable, he or she may be sent for CT. If a patient comes into the emergency department with shortness of breath, a quick ultrasound may reveal a pneumothorax or congestive heart failure, and the physicians can act on that immediately without sending the patient for chest radiography.

In some places outside of the United States where imaging resources are limited, ultrasound can have a huge impact. One example is maternal death in such places as Africa. A large percentage of maternal death related to pregnancy could be avoided. POC ultrasonography could date the pregnancy, determine fetal lie and placental location, and evaluate for abnormalities.

Medscape: Would that be an example of a clinical evaluation?

Dr. Nisenbaum: Yes; that is POC ultrasound used at the time the patient is being evaluated.

Medscape: With the development of more handheld ultrasound devices, what attributes would you say are required?

Dr. Nisenbaum: The handheld units should be easy to use, lightweight, affordable, and durable and have long battery life. They should have interchangeable transducers, good image quality, and the ability to transmit images.

Medscape: What distinguishes these systems from the larger console-based systems that you would find in a radiology department?

Dr. Nisenbaum: There are 3 categories of units. One is the larger stand-alone unit that would be in a large department, such as radiology, cardiology, or ob/gyn. It will be on wheels and can be moved around. The next-smaller group is the laptop type of unit that can be on a portable cart or hand-carried. Then you get into the small handheld device There are relatively few on the market at this time.

Medscape: What do the laptop and handheld units give up in terms of capabilities you would find in bigger units?

Dr. Nisenbaum: Because of miniaturization, the smaller units are getting closer and closer to providing the same image quality as the larger units. With larger units, you have the advantage of being able to plug in many transducers at the same time. The laptop can become more difficult to carry if it is configured with many components, but the quality of imaging is becoming very similar. At this time, the much smaller handheld units have limited flexibility. The laptop image quality depends on how the they are configured and what technology they have. The type of unit and its configuration depends on what studies are going to be performed.

Medscape: Do the smaller units have any particular challenges?

Dr. Nisenbaum: In a traditional department where patients with various clinical symptoms need to be evaluated, the larger units need to have multiple transducers and be capable of performing many varied studies. For focused studies, a smaller unit with a few transducers might be appropriate. If you only perform MSK ultrasound, your unit will be configured differently from that of somebody who is doing obstetric or abdominal ultrasound.

Medscape: What are the implications of this for radiologists who are involved in ultrasonography?

Dr. Nisenbaum: Ultrasound is one of the few modalities in which the images are created by the person who is performing the study. The person who is applying the transducer to the patient and creating the image has to understand ultrasound physics, how to adjust the individual machine controls, patient safety, infection control, and image quality and be competent to perform the appropriate study. Ultrasound image acquisition is unlike CT or MRI, where the technologist sets the parameters and the CT or MRI machine acquires and creates the images.

Many radiology departments have radiologists who are expert in the use of ultrasound. They can be a resource to help other healthcare providers learn how to perform an ultrasound scan, especially providers who don’t have access to that expertise in their own department. This can become a turf issue because, in a fee-for-service environment, there is a worry that if you teach people to do something, they may start doing studies and billing for studies that you might have performed.

Ultrasound is a very powerful and safe tool to help patients. It is crucial that healthcare providers who are using ultrasound be trained appropriately and have the competence to use it effectively to get the most specific diagnosis or to perform a procedure safely.

Radiology departments are relative value unit (RVU)-driven and therefore tend to emphasize CT and MRI over ultrasound, which is more hands-on and labor intensive and generates fewer RVUs. It is important for radiology residents to be properly trained in the use of ultrasound because healthcare providers outside of radiology using POC ultrasound may obtain findings they don’t understand and probably refer those patients to the radiology department for additional imaging.

Imagine if your internist was competent in the use of POC ultrasound. It would become part of your evaluation. For example, do your carotid arteries appear normal? If not, you would be sent to the vascular laboratory for a more detailed workup. Do you have an abdominal aortic aneurysm or gallstones? Rather than using a stethoscope to evaluate your heart, ultrasound can visualize your heart anatomy and function.

Before this can happen, however, healthcare providers need to be well trained. What will be the training, and by whom? How do you document it? How do you evaluate competency? The AIUM has been working with many specialties to develop performance and training guidelines for ultrasound. The AIUM and American College of Radiology (ACR) also have accreditation programs for ultrasound practices.

Medscape: Is there anything else you would like to bring to this discussion?

Dr. Nisenbaum: POC ultrasound is going to be pervasive. In the future, I predict the majority of healthcare providers will be using it.


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