The stethoscope is nearing its 200th birthday, and some medical experts believe that it’s time for an upgrade. These individuals maintain that the underpinnings of the stethoscope’s replacement exists: ultrasound technology. Within a few years—a decade, at most—they say, ultrasound technology will be miniaturized. According to these experts, handheld ultrasound devices, reminiscent of the Star Trek tricorder, might find their way into ERs. Then they will be adopted by doctors everywhere. This prediction isn’t without its detractors, however. While it’s true that handheld ultrasound technology is on the horizon, it has a few limitations. First, though, let’s discuss its strengths
The Benefits of Ultrasound Technology
Like the stethoscope, ultrasound gleans information about the body without damaging body tissues. Ultrasound is nothing more than tightly focused sound waves, after all. If used properly, it’s perfectly safe. Here are a few other advantages it has over other imaging technologies such as MRI and the mammogram:
• Can detect lesions that mammogram cannot
• Creates a clearer image than a mammogram, allowing doctors to identify lesions without biopsy
• Less expensive than mammogram and MRI
• Can create clear images of the heart as it pumps
• Is the only known way of differentiating between a cyst and a solid mass without biopsy
• Can visualize blood-flow through arteries and blood vessels surrounding the heart
Clearly, ultrasound has a lot going for it. There is, however, one significant drawback to the technology.
In his paper, Effects of Gas Pockets on High-Intensity Focused Ultrasound Field, Dr. Hussein S.H reveals that the presence of air pockets in body tissues can significantly reduce the image clarity generated by ultrasound devices. According to the paper, a 1.2-mm air bubble reduces the focal intensity of an average ultrasound device by up to 50%. Even more startling, air bubbles can obscure a scan, so that lesions and other features appear as an echo. This can cause doctors to make extra incisions when extracting tissue for biopsy.
Other Limitations of Ultrasound
Ultrasound has several other drawbacks:
• Can cause benign growths and lesions to appear malignant
• Cannot detect heart conditions reliably
• Not all insurance plans cover the use of ultrasound
• Ultrasound requires highly experienced operators
The echocardiogram, or ultrasound of the heart, has progressed rapidly the last few decades. This medical procedure can determine the size and shape of the heart, and it can allow physicians to observe the heart beating in real time. The test illuminates the heart valves and gives insight into the health of the blood vessels surrounding the muscle. With the echocardiogram, doctors can diagnose valve conditions, identify changes in the heart’s structure, and assess damage after a heart attack. However, the ultrasound in a vacuum is not a particularly useful tool. Doctors must hear the sounds that the pumping heart produces to get the full picture.
The Stethoscope Dominates
Despite its numerous strengths, handheld ultrasound devices have another mighty weakness: they rely on electricity. If battery powered, these devices will need to be charged frequently, as they will use an immense amount of power. In emergencies, when doctors need access to tried and true diagnostic tools, they will inevitably reach for a sturdy analog stethoscope such as the Littmann Master Cardiology.
High-end stethoscopes can tell a doctor all they need to know about a patient’s heart in a triage situation. What’s more, the stethoscope is infinitely cheaper to operate over time than ultrasound. As of 2014, a standard echocardiogram costs between $1,000 and $2,000 a pop. Doubtless, medical students may find it difficult to gain access to a handheld ultrasound device any time soon. This is, perhaps, the source of the stethoscope’s staying power: it’s an affordable diagnostic tool that is sufficient in most cases.