Diagnostic imaging embraces several procedures that aid in diagnosing ailments. Besides the familiar x ray, another common diagnostic imaging method is magnetic resonance imaging, which uses giant magnets that create radio waves, rather than radiation, to form an image. Not all imaging technologies use ionizing radiation or radio waves, however. Sonography, or ultrasonography, is the use of sound waves to generate an image for the assessment and diagnosis of various medical conditions. Many people associate sonography with obstetrics and the viewing of the fetus in the womb, but this technology has many other applications in the diagnosis and treatment of medical conditions.
Diagnostic medical sonographers, also known as ultrasonographers, use special equipment to direct nonionizing, high frequency sound waves into areas of the patientís body. Sonographers operate the equipment, which collects reflected echoes and forms an image that may be videotaped, transmitted, or photographed for interpretation and diagnosis by a physician.
Sonographers begin by explaining the procedure to the patient and recording any medical history that may be relevant to the condition being viewed. They then select appropriate equipment settings and direct the patient to move into positions that will provide the best view. To perform the exam, sonographers use a transducer, which transmits sound waves in a cone- or rectangle-shaped beam. Although techniques vary with the area being examined, sonographers usually spread a special gel on the skin to aid the transmission of sound waves.
Viewing the screen during the scan, sonographers look for subtle visual cues that contrast healthy areas with unhealthy ones. They decide whether the images are satisfactory for diagnostic purposes and select which ones to show to the physician.
Diagnostic medical sonographers may specialize in obstetric and gynecologic sonography (the female reproductive system), abdominal sonography (the liver, kidneys, gallbladder, spleen, and pancreas), neurosonography (the brain), or ophthalmologic sonography (the eyes). In addition, sonographers may specialize in vascular technology or echocardiography. (Vascular technologists and echocardiographers are covered in the Handbook statement on
cardiovascular technologists and technicians.)
Obstetric and gynecologic sonographers specialize in the study of the female reproductive system. Included in the discipline is one of the more well-known uses of sonography: examining the fetus of a pregnant woman to track its growth and health.
Abdominal sonographers inspect a patientís abdominal cavity to help diagnose and treat conditions involving primarily the gallbladder, bile ducts, kidneys, liver, pancreas, and spleen. Abdominal sonographers also are able to scan parts of the chest, although studies of the heart using sonography usually are done by echocardiographers.
Neurosonographers focus on the nervous system, including the brain. In neonatal care, neurosonographers study and diagnose neurological and nervous system disorders in premature infants. They also may scan blood vessels to check for abnormalities indicating a stroke in infants diagnosed with sickle-cell anemia. Like other sonographers, neurosonographers operate transducers to perform the sonogram, but use frequencies and beam shapes different from those used by obstetric and abdominal sonographers.
Ophthalmologic sonographers use sonography to study the eyes. Sonography aids in the insertion of prosthetic lenses by allowing accurate measurement of the eyes. Ophthalmologic sonography also helps diagnose and track tumors, blood supply conditions, separated retinas, and other ailments of the eye and the surrounding tissue. Ophthalmologic sonographers use high-frequency transducers, made exclusively to study the eyes, which are much smaller than those used in other specialties.
In addition to working directly with patients, diagnostic medical sonographers keep patient records and adjust and maintain equipment. They also may prepare work schedules, evaluate equipment purchases, or manage a sonography or diagnostic imaging department.
Most full-time sonographers work about 40 hours a week. Hospital-based sonographers may have evening and weekend hours and times when they are on call and must be ready to report to work on short notice.
Sonographers typically work in healthcare facilities that are clean and well lighted. Some travel to patients in large vans equipped with sophisticated diagnostic equipment. Sonographers are on their feet for long periods and may have to lift or turn disabled patients. They work at diagnostic imaging machines, but also may perform some procedures at patientsí bedsides.
Diagnostic medical sonographers held about 37,000 jobs in 2002. More than half of all sonographer jobs were in hospitals. Most of the rest were in offices of physicians or in medical and diagnostic laboratories, including diagnostic imaging centers. According to data from the Sonography Benchmark Survey conducted by the Society of Diagnostic Medical Sonography, about 3 out of 4 sonographers worked in urban areas.
There are several avenues for entry into the field of diagnostic medical sonography. Sonographers may train in hospitals, vocational-technical institutions, colleges and universities, and the Armed Forces. Some training programs prefer applicants with a background in science or experience in other health professions, but also will consider high school graduates with courses in mathematics and science, as well as applicants with liberal arts backgrounds.
Colleges and universities offer formal training in both 2- and 4-year programs, culminating in an associate or a bachelorís degree. Two-year programs are most prevalent. Course work includes classes in anatomy, physiology, instrumentation, basic physics, patient care, and medical ethics. The Commission on Accreditation for Allied Health Education Programs accredits most formal training programsabout 102 programs in 2003.
Some health workers, such as obstetric nurses and radiologic technologists, increase their marketability by seeking training in fields such as sonography. This usually requires completion of an additional 1-year program that may result in a certificate. In addition, sonographers specializing in one particular discipline often seek competency in others; for example, obstetric sonographers might seek training in, and exposure to, abdominal sonography to broaden their opportunities.
Although no State requires licensure in diagnostic medical sonography, organizations such as the American Registry of Diagnostic Medical Sonographers (ARDMS) certify the competency of sonographers through registration. Because registration provides an independent, objective measure of an individualís professional standing, many employers prefer to hire registered sonographers. Registration with ARDMS requires passing a general physics and instrumentation examination, in addition to passing an exam in a specialty such as obstetric and gynecologic sonography, abdominal sonography, or neurosonography. To keep their registration current, sonographers must complete continuing education to stay abreast of technological advances related to the occupation.
Sonographers need good communication and interpersonal skills because they must be able to explain technical procedures and results to their patients, some of whom may be nervous about the exam or the problems it may reveal. Sonographers also should have a background in mathematics and science.
Employment of diagnostic medical sonographers is expected to grow faster than the average for all occupations through 2012 as the population grows and ages, increasing the demand for diagnostic imaging and therapeutic technology. In addition to job openings due to growth, some job openings will arise from the need to replace sonographers who leave the occupation permanently.
Opportunities should be favorable because sonography is becoming an increasingly attractive alternative to radiologic procedures, as patients seek safer treatment methods. Unlike most diagnostic imaging methods, sonography does not involve radiation, so harmful side effects and complications from repeated use are rarer for both the patient and the sonographer. Sonographic technology is expected to evolve rapidly and to spawn many new sonography procedures, such as 3D-sonography for use in obstetric and ophthalmologic diagnosis. However, high costs may limit the rate at which some promising new technologies are adopted.
Hospitals will remain the principal employer of diagnostic medical sonographers. However, employment is expected to grow more rapidly in offices of physicians and in medical and diagnostic laboratories, including diagnostic imaging centers. Health facilities such as these are expected to grow very rapidly through 2012 due to the strong shift toward outpatient care, encouraged by third-party payers and made possible by technological advances that permit more procedures to be performed outside the hospital.
Median annual earnings of diagnostic medical sonographers were $48,660 in 2002. The middle 50 percent earned between $41,420 and $56,020 a year. The lowest 10 percent earned less than $35,800, and the highest 10 percent earned more than $66,680. Median annual earnings of diagnostic medical sonographers in 2002 were $50,390 in offices of physicians and $47,530 in hospitals.
Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2004-05 Edition,
Diagnostic Medical Sonographers, on the Internet at
(visited July 09, 2004).