<title>The Physician's Need For Standardization Of Ultrasonic Instrumentation</title>

Abstract

The physician's need for standardization of ultrasonic instrumentation might appear to be too obvious a requirement to be worthy of further comment.Nevertheless, many engineers do not appreciate the extent to which the diagnostic process in ultrasound as currently practiced is dependent upon the subjective impressions of the interpreter and the variations that occur in similar models of the same machine or the drift in any single machine with time.Diagnostic ultrasound is capable of producing highly diagnostic data without discomfort to the patient, injection of contrast media, ionizing radiation or undue expense. At this institution, ultrasound examinations now exceed 10,000 per annum; and this use of ultrasound has decreased the need for highly invasive procedures such as angiography or expensive ones such as whole body x -ray computerized tomography (CT). Despite these advantages, at some other hospitals, ultrasound is not available, even for obstetrics, and there are a number,of obvious restrictions to the rapid acceptance of this useful technique: 1)There is a lack of adequately trained technicians to produce diagnostic scans. 2)There is a dearth of physicians trained in the interpretation of ultrasound. This is a markedly different problem from the acceptance of a new x -ray technique such as CT.In x -ray CT scanning the basic physics of ionizing radiation is familiar to radiologists, and the systems investigated are those for which the anatomy and pathology is already well known. In contrast, the physics of ultrasound is new to radiologists, while the anatomy and pathology of the organs studied, including the heart, liver, obstetrics and gynecology, lay outside the realm of general radiological procedures. 3)Ultrasound equipment is poorly standardized, subject to drift and, most important, there appears to be a total lack of any adequate tissue phantom on which the equipment performance can be optimized before clinical use.The answer to the first problem lies in increased training programs for technicians and stricter certification requirements, together with the development of automated scanners. The lack of physician training will slowly be overcome as ultrasound training becomes a requisite for Board certification in radiology. There remains the problems inherent in unstable and suboptimal equipment which must be appreciated by industry before any solutions can be provided.A physician wishing to institute an ultrasound service may purchase a machine which is deemed to be capable of generating grey -scale images of diagnostic quality.The chance of having such a machine delivered from the factory in our experience is small. The rigorous tests to which the machine is subjected before delivery may not include the production of clinical images. This deficiency indicates the great need for an adequate tissue phantom so that specifications of the machines which are relevant to the production of clinically useful scans can be more adequately tested. One standard test currently employed involves the AIUM test ob...