News from the ultrasound front
Avoiding abuse and overuse of ultrasound

Rinckside 1995; 6,2: 5-7.

ometimes you hear or read statements that are beyond belief. The March issue of the U.S.-American edition of Diagnostic Imaging contained quite a stunning article with the title “Ultrasound Portraiture: Glimpses of Fetal Space”. The authors propose that they may distinguish states of serenity and distress, hunger and pain from viewing the face of the fetus in utero with ultrasound. In the future, prenatal face viewing performed by ultrasound will be requested and eventually demanded as part of each ultrasound study, they suggest. Images should be in pseudocolors – preferably in gold tones, which promote a feeling of warmth and emphasize the notion of an ultrasound probe as a sonic “flashlight”.

It is the authors’ impression that “frontal views … provoke comments about resemblances within the family, while more idealized profile views tend to elicit comments about projected futures or anticipated personal attributes.”

Because of the clarity of the images it provides, an endovaginal probe should be used to view the face whenever the fetus is in a prone or semiprone vertex position, the advise [1].

Is the ultrasound operator going to become the prenatal family photographer of the 1990s?

   Not everybody seems to like this idea. At the time of publication of the article, the International Herald Tribune, a U.S. newspaper published in Paris, printed the following short note (25 February 1995):

“An ultrasound videotape of a baby swimming in the uterus is a useful diagnostic tool for doctors. But such tapes should not be made simply as souvenirs for the expectant parents, according to the [United States] Food and Drug Administration. It has warned nonmedical companies that offer to make such videotapes that they risk seizure of their equipment. Ultrasound can produce physical effects in tissue, such as a rise of temperature. ‘Although there is no evidence that this can harm the fetus,’ an agency spokesman said, ‘public health experts agree that casual exposure to ultrasound, especially during pregnancy, should be avoided.’”

In the year of Roentgen’s centenary, we have all seen the x-ray pictures of both Herr and Frau Roentgen’s hands. They are a great souvenir in the history of roentgenology and medicine itself. However, radiation protection regulations do not allow such souvenirs to be available today. Are the ultrasonic smiling baby faces going to have the same fate?

There is no evidence that B-mode scanners lead to any deleterious effects, particularly on fetus or mother when used for routine clinical scanning during pregnancy. However, some Doppler equipment has the potential to produce a biologically significant temperature rise, specifically at bone/soft tissue interfaces. Doppler flow studies in the fetus work with intensities at which thermal effects cannot be excluded.

Lower costs?

There are other arguments against unrestricted and medically unsolicited overuse of ultrasound. It adds to the cost explosion in the healthcare system. I hear your argument that ultrasound is the cheapest diagnostic imaging modality. In the same manner, you can argue that a motorcycle is cheaper than a car. But if you buy ten motorcycles you will spend more money on acquisition, running costs, and maintenance than for one car.

At the opening session of the Annual Meeting of the Radiological Society of North America in 1994, radiology chairman Christopher R.B. Merrit of the Ochsner Clinic in New Orleans, quoted the direct cost of an ultrasound examination at US$ 28.90. Direct costs of a plain x-ray were US$ 11.93; of fluoroscopy US$ 42.23; of CT US$ 77.65; and of MRI US$ 143.04 [2].

In Germany, at least 30,000 non-radiologists (three times more than the total number of radiologists) perform x-ray and/or ultrasound examinations, especially in internal medicine, orthopedics and pediatrics. Total expenditure on ultrasound is three times higher than on CT and MRI combined. It should be asked, then whether the diagnostic outcome of ultrasound is proportionally three times higher?

In 1958, C. Northcote Parkinson published a book entitled “Parkinson’s Law”. His law basically boiled down to the following: Put a typewriter in the desert and a bureaucracy will grow around it.

Similarly, Rinck’s Law on Ultrasound states: “Put an ultrasound machine anywhere and there will be an explosion of unnecessary examinations with this machine – or, if it's hidden behind the door, no examinations at all.” I can hear the outcry. But if you start reading recent publications on ultrasound, you will find some statements by developers and users of this imaging modality which are quite critical of certain of its applications.

Dubious applications

Some time ago, a friend of mine had knee problems. After clinical examination by an orthopedic surgeon, x-rays of his knees were taken, then he underwent an ultrasound examination. Neither of the imaging studies was conclusive, so he was referred to MR imaging.

This is not an uncommon occurrence. During the last years, people have started using ultrasound in orthopedics, for instance, to examine the menisci and cruciate ligaments. This adds one more examination to the list, but the question: “Why use ultrasound?” remains a taboo.

In a recently published paper on ultrasonography in arthritis of the knee, the authors conclude:

“The present study confirms that US is a reliable method for demonstration of joint effusions and Baker's cysts. The synovial membranes of the suprapatellar recess could be identified in approximately half of the patients … Although cartilage evaluation by US seems reliable, the clinical value is limited, because the weight-bearing areas are inaccessible. Since MR imaging additionally may provide information about early pannus-induced cartilage and bone erosions, the synovial membrane volume, and the inflammatory activity of the joint, MR imaging for the moment must be preferred second imaging modality to conventional radiography in rheumatoid arthritis and osteoarthritis, except when Baker’s cysts are suspected [3]."

Cranial sonography is also increasingly used in the detection of intracranial changes and complications in infants. The following is the conclusion of a study in 58 infants conducted between 1988 and 1993 at the Massachusetts General Hospital in Boston:

“Current cranial sonography protocols in ECMO (extracorporeal membrane oxygenation) patients are not maximally efficacious. Incorporation of an analysis of clinical parameters routinely followed in these neonatal intensive care unit patients should identify those at increased risk of acute intracranial hemorrhage, increasing the yield of this sensitive but time and cost intensive modality [4]."

Ethics

There is also the medical ethics issue to consider.

In China and some other Asian countries, demographic statistics show a significant change in the composition of the younger population. The share of the male population has increased substantially during the recent years, and in some areas of China it has become almost impossible for young men to find a woman to marry. Bachelorhood is the grim prospect for many young Chinese men. Kidnapping and trading of women has increased sharply.

This change in population structure has been aided by ultrasound. In the eyes of a great number of Chinese, it is better to have sons than daughters, so when ultrasound examinations reveal the sex of the fetus to be female, it is aborted. Although both China and India have introduced legislation to ensure against this abuse, it nevertheless continues.

A positive contribution to diagnostics

The abstract of a refresher course at the 1995 European Congress of Radiology describes ultrasound in a typical manner as follows:

“Ultrasound is simple, rapid, inexpensive, dynamic, and can be repeated as often as necessary without known hazard to the patient. It does, however, require dedication, skill and experience. When properly integrated with the clinical data and the results of other radiological examinations, US provides a wealth of information which has a crucial impact on therapeutic management [5]."

This description should be kept in mind and ultrasound should be used accordingly. Furthermore, ultrasound is versatile, able to image solid organs, vessels, and the fetus in a variety of clinical settings, and quite importantly, the equipment is portable and can be brought to the patient. Personally, I would like to emphasize the need for “proper integration” of ultrasound.

As with any diagnostic imaging modality, there are two major risks associated with ultrasound: misdiagnosis and overuse. Because ultrasound is far more operator-dependent than other methods, the risk of misdiagnosis is higher than with other modalities. Therefore, it is essential that training deals not only with how to use the technique but also when to use it with prudence. Unfortunately, such training is not available or required in all countries, including some in Europe.

Recent undesirable trends are overshadowing the positive contribution that ultrasound makes to diagnostics. Unless action is taken to reverse these trends, the risk is that ultrasound will be remembered as the not-so-ultracheap and ultra-abused imaging modality of the last decade of the 20th century.

References

1. Birnholz JC, Bregman J. Ultrasound Portraiture: Glimpses of fetal space. Diagnostic Imaging (US edition) March 1995, 31-33.
2. Merrit CRB, quoted in Diagnostic Imaging (US edition) January 1995, 11.
3. Østergaard M, Court-Paven M, Gideon P, et al. Ultrasonography in arthritis of the knee. A Comparison with MR imaging. Acta Radiol 1995; 36: 19-26.
4. Puylaert JBCM. Ultrasonography State-of-the-Art (abstract RC 414). 9th European Congress of Radiology, Vienna 1995. Scientific Program and Abstract. Europ Radiol 1995; 5, S1: S51.
5. Tucker JI, Bramson RT, Blickman JG, Kruatrachue A. Cranial sonography in the detection of acute intracranial complications in infants on ECMO: An analysis of the efficacy of current imaging protocols. Proceedings of the 31st Congress of the European Society of Radiology. Stockholm 1994.

Citation: Rinck PA. News from the ultrasound front: avoiding abuse and overuse of ultrasound. Rinckside 1995; 6,2: 5-7.

A digest version of this column was published as:
News from the ultrasound front: avoiding abuse and overuse of ultrasound.
Diagnostic Imaging Europe. 1995; 11,4: 15-16.