Quality Assurance in Ultrasound
By Harry H. Holdorf
Ultrasound is unique in many ways. Most notably, it is categorized as radiological even though
ultrasound uses sound waves as opposed to ionizing radiation. In an era in which radiation
exposure is of increasing concern, ultrasound stands out for its safety profile.
How is radiation produced in the medical imaging departments? The equipment used in imaging
departments produce radiation. For example the CT scanner uses radiation to record images.
Nuclear medicine uses radioactive nucleotides.
With the technology in the hands of so many specialists, training becomes critical and the skills
of the technologist or sonographer are paramount to the quality of the exam. These and other
distinguishing characteristics of the technology have important service implications.
Ultrasound is in a funny spot. It is between an imaging device and a 'biomed' device. Hospitals
typically have costly service contracts for high-end equipment such as CT scanners, while
lower-cost equipment such as patient monitors are typically maintained by in-house biomedical
staff. Ultrasound is not quite an MRI or CT and not quite a patient monitor in the sense of
service arrangements. It is one of those assets that hospitals have targeted to bring in house for
servicing, since the value proposition is there and training and parts are available.
The medical imaging department needs a quality assurance program to ensure that all possible
measures are being taken to detect, diagnose and treat any lesion as soon and effectively as
possible. Also to ensure that exposure to radiation is being kept to a minimum. Quality assurance
programs help the department to function optimally. They check equipment, employee
credentials, safety controls and general functioning of the departments
There are Quality assurance programs for ultrasound department that are in place. These are
needed because ultrasound employees can perform an ultrasound study on a patient who has just
come from the nuclear medicine department and can therefore be exposed to radiation. Also
sonographers must use calibrated equipment for quality images.
Radiation exposure in the Medical Imaging department is constantly being measured. All
employees working around a facility using radiation must wear a radiation badge. This badge is
checked at regular intervals by a Health physicist. This ensures that the individual has not been
exposed to high levels of radiation.
ALARA stands for “As low as reasonably possible”. It is the motto for all imaging departments.
It is the policy to ensure that all possible measures have been taken to minimize the exposure to
radiation as much as possible thereby safeguarding the health of employees and patients to
radiation. The minimal amount of radiation that is needed for the procedure is used.
Industry experts report that hospitals have increasingly taken on maintenance and servicing of
ultrasound equipment themselves, either through their own staff, asset managers on site, or
through independent service organizations. Because most facilities have multiple ultrasound
units, service issues are extremely important to healthcare providers' bottom line.
You see a lot of sensitivity on the service side because many sites have 10-20 ultrasound
machines; you don't just have one system, which is typical with MR or CT scanners. That is
why we see providers considering lower-cost alternatives as long as the quality of service is
there.
Ultrasound is very interesting because unlike MR or CT, ultrasound fits very well into the core
competencies of the existing biomed department. You don't need a PhD like you do to service
an MR or CT.
Preventive maintenance is essential but often inadequately performed. American College of
Radiology standards call for two preventive actions per year along with probe testing. Here, as
in most service areas, there can be huge difference in the meticulousness of providers.
For instance, simple environmental conditions like linen changes and heating, ventilating, and
air conditioning (HVAC) can stir up dust particles. One has to go in and monitor the system
and make sure all the fan filters are running clean and free to minimize dust and dirt buildup. If
you do, uptime increases exponentially. A lot of in-house biomed departments have realized
this.
The importance of Time, Distance and Shielding cannot be overstated. The exposure time must
be kept as low as possible. Adequate distance must be kept from the patient. As you double
distance from radiation force 1 unit decrease by a factor of 4. Shielding must be done for
adequate protection. Lead apron, gonad shields, thyroid shields must be used as needed. Lead
walls must be present in the facility.
Quality assurance programs for the medical imaging department entail are quite involved. The
quality assurance programs have improved the safety, quality and standards in all areas of the
medical imaging departments. In MQSA (medical quality standard act) the federal government
has got actively involved. All equipment is tested regularly, weekly phantom machines,
processor quality control, dark room fog test, compression analysis of 25-40 pounds on the breast
by the machine must be maintained and laser tests are done.
Sonography Technologists and Student Sonographers students are have a slight risk for exposure
to radiation. This is because in most hospitals all imaging departments are close to each other.
There will be some radiation in the premises. Also the Sonographer may have to treat a patient
who has just come from the Nuclear Medicine department and therefore they would be close to
radiation. Also they may have to do an echocardiograph on a patient who has had some radiation.
As a healthcare worker, you can be exposed to 5000mg of radiation for the whole Year. It is
preferred not to get more than 10 % of this amount (i.e. 500mg/year.
If you become pregnant while in working in Ultrasound, you should inform your supervisor. If
possible you can be put in areas of the facility not exposed to radiation.
Also you should wear a lead apron covering the abdomen and a radiation badge near the
abdomen.
Sonographers should wear the film badge between your collar and waist.
You should immediately inform your supervisor and fill out an incident report. You should send
your film badge for an emergency reading. You should use liquid soap and wash your skin and
inform the safety officer.
A good Quality Control (QC) or Quality Assurance (QA) program should be in place for all
ultrasound departments to not only protect patients and healthcare workers, but to produce the
highest quality images to assure that the department is providing the best possible patient care.