It's important to us to keep you informed about changes in medical physics regulations -- and it's also our pleasure to keep you informed as part of our commitment to customer service.
Read our blog often for the latest updates and expert medical physics advice from our skilled team.
Protective Apron Inspection
Posted on Tuesday, June 11th, 2013, under Radiation Safety
By Greg Sackett, M.S., CHP
The inspection of radiation protective aprons is a mysterious requirement without much guidance. Many hospitals and clinics have heard something about inspecting aprons, but many have questions as to what they need to do.
The primary requirement for protective apron inspection is given by the Joint Commission. Some States also require inspection of protective aprons but Missouri, Kansas and Iowa do not have any such requirements. This means that technically only those institutions accredited by the Joint Commission are required to inspect their protective aprons annually.
The Joint Commission requirement may be satisfied by physical inspection OR fluoroscopic examination of protective aprons annually. While fluoroscopic examination is believed to be more thorough, it may not be necessary for newer aprons and may deliver unnecessary exposure to the persons testing the aprons. Fluoroscopic testing may be considered for aprons considered suspect following physical examination. If fluoroscopic testing is performed, low technique factors and not automatic exposure control should be used to reduce operator exposure.
The keys to a successful apron inspection program are as follows:
- Uniquely identify each item of protective equipment with a number and some method of determining when it was last inspected. This may be done on the label/tag itself or with a database that tracks all of the items and when they were inspected. If a database is used, results must be available for inspection by the Joint Commission.
- Develop a procedure for inspecting the protective equipment, either physically or fluoroscopically (or both).
- Develop criteria for determining when protective equipment is defective. Such criteria may include:
- Tears, perforations, or seam separation.
- Holes larger than 15 mm2 unless it is not positioned over a critical organ.
- Velcro that is no longer functioning.
- Aprons determined to be defective should be removed from service immediately and disposed of properly (as hazardous material/waste if they contain actual lead).
Establishment of a protective apron inspection program may not be required at your facility but should be considered in order to give assurance to staff that the protective equipment they have available is not defective.
References:
- “Inspection of lead aprons: Criteria for rejection,” Operational Radiation Safety Volume 80, May 2001
- “Implementation of an X-ray Radiation Protective Equipment – Inspection Program” published in Operational Radiation Safety Vol 82, Feb. 2002, pp 551-553
Communicating Radiation Risk to Patients
Posted on Thursday, April 18th, 2013, under Radiation Safety
By Greg Sackett, M.S., CHP
Responding to patient concerns and questions about radiation risk can be one of the most challenging duties facing technologists and physicians. Patients often arrive with preconceived notions of risk based on misinformation they have seen in the media or read on the internet. They may be scared or even hostile towards the caregiver attempting to complete a prescribed procedure.
When discussing risk, perception equals reality, regardless of scientific or technical evidence to the contrary. Therefore it is necessary to discuss risk within the patient’s perception of the hazard. The keys to remember when discussing risk with the patient are:
- Tell the truth.
- Use positive or neutral terms and no jargon.
- Use examples to help the patient understand.
- Don’t speculate, discuss only the procedure being performed.
- Do not attack the patient’s beliefs or a source of misinformation.
- Ask if you are being understood.
Ensure the patient that the procedure will be performed using good radiation safety practices that are designed to keep the doses as low as possible while still generating the diagnostic results required. Be careful generalizing risks, as future cancer risk is highly age dependent. Many radiation induced cancers have latency periods of 10 to 20 years. While individuals over 60 have minimal cancer risks from radiation exposure, children have a lifetime risk of 10-15% simply due to the length of time available for cancer to appear.
One aspect often overlooked when discussing radiation risks is the BENEFIT to the patient of the procedure being performed. The risks of NOT performing an exam include missing a diagnosis and/or initiating treatment too late to improve the medical outcome. This risk must be considered in conjunction with the latency period for radiation-induced cancer and the age of the patient. The use of radiation in healthcare saves thousands of actual lives every year, while the entirely theoretical risks predicted by risk models are orders of magnitude smaller. Ensure that the patient understands why the procedure is being performed and the benefit to their immediate health.
If the patient has questions that you cannot answer, they may be referred to the Radiologist or Radiation Safety Officer of your institution. You may also refer them to trusted websites like RadiologyInfo.org that are designed to answer patient questions about Radiology and Radiation Safety.
References:
- How to Understand and Communicate Radiation Risk, Peck and Samei, Imagewisely.org
- Benefits of Medical Radiation Exposures, Zanzonico and Stabin, HPS.org
What Can We Say About Patient Dose in CT Exams?
Posted on Tuesday, April 2nd, 2013, under CT
By Stephen E. Hale Jr., Ph.D.
Radiation dose from Computed Tomography (CT) exams has recently become a hot topic among the medical community, the legal community, and the public in general. Overdoses from brain perfusion studies at several medical facilities in California and Alabama have contributed to this rise in concern. But what can a CT technologist or radiologist actually tell their patients about the amount of radiation administered during a CT exam?
Each CT machine will typically provide both an estimated CTDIvol and DLP value before an exam is conducted. CTDIvol stands for volume Computed Tomography Dose Index, while DLP stands for Dose-Length Product. Neither of these is actually a measure of the dose a patient will get from the exam. They are actually designed as metrics for comparing one protocol to another, one machine to another, or even one facility to another, in terms of the amount of radiation produced by the system. As such, they can be used to guide adjustments to the techniques of a given protocol, such as kVp, mA, rotation time, mAs, or even pitch for helical scans.
Dose is defined as the amount of energy absorbed from radiation passing through material divided by the amount of mass that is actually absorbing the energy. The more energy absorbed in the same amount of matter, such as a patient’s body, the more dose is absorbed, and therefore the greater potential for damage. Similarly, the same amount of energy absorbed in a smaller body will also result in a greater potential for damage.
The CT machine has no knowledge about the patient who will be scanned nor what portion of the patient’s anatomy will be examined. If a large patient is scanned with the same techniques as a small patient, the smaller patient will have less mass exposed to the same amount of radiation, and thus experience a higher dose. Different portions of our bodies are more sensitive to radiation than others. Thus having a CT exam with a set of technique factors over a patient’s feet will have much less detriment to the patient than the same exam over a patient’s head.
A good analogy to this situation is that of a tachometer in a car relative to the car’s speed. The tachometer displays how many revolutions per minute the engine is spinning the crankshaft, but it has no knowledge about the gear selected by the transmission or the size of the wheels and tires on the car. For a given RPM, a higher gear means a faster speed. Similarly, if the wheels and tires are replaced with a larger set, a given RPM of the engine and the same gear will result in a faster speed. The CTDIvol and DLP values are the equivalent of the tachometer, reporting how the CT machine is performing. But without information about the patient undergoing the procedure, nothing can be said about the dose absorbed.
Without knowledge of the patient’s size or the anatomy being scanned by the CT, it is not possible to tell the patient how their radiation dose compares to other sources or exams. With images of the patients and information about the parameters of the exam on the CT system, physicists can calculate actual radiation doses to patients. This is one of the many services provided by Integrated Science Support, Inc.
References:
- “Two more hospitals report CT scan radiation overdoses” LA Times, Online 8/3/2010
Radiographic Technique Still Matters For Image Quality and Patient Dose
Posted on Saturday, March 23rd, 2013, under Radiography
Shirley Bartley, M.B.A., RT (R)(N)
The new technologist at the hospital radiology department went to do a portable in the ICU. The patient looked average size. She looked for the technique chart to set the correct exposure factors. There was no chart to be found. She guessed at the technique based on what she could remember from the last place she worked. When the new tech returned to the department the supervisor was reviewing the image. “You are going to have to repeat this portable chest. There is an image quality problem. You didn’t penetrate the mediastinum.” The supervisor told the new tech.
If the kVp is too low the anatomy will not be properly penetrated. The fine detail in dense areas of the body will just not be there. This will jeopardize the radiologist ability to make a correct interpretation of the patient’s condition.
A few minutes later the new tech was working in room 2 with a seasoned employee. The new tech selected the radiographic technique from the anatomic programing feature on the operator’s consol. “Don’t use that. It doesn’t work. I have my own technique.” The new technologist made a mental note to try to remember the technique.
Without standard technique systems that are used by everyone image quality will be inconsistent. It is difficult for the radiologist to see changes in the patient’s condition when totally different radiographic technique is used. Technologist that just “remember” their own techniques are frequently wrong.
After lunch the new tech was working with a radiology student. They did an abdomen using automatic exposure control (AEC). Viewing the image, the new tech pointed out that the exposure indicator value was well above the acceptable range. The students said, “They don’t pay any attention to the number here.”
With digital systems the image that is over exposed no longer comes out black. The only way we can determine that the patient was over exposed is with the exposure indicator value. The AEC unit that is not properly calibrated will not produce the correct quantity of radiation for the image. When the exposure indicator value is ignored the patients may be overexposed unnecessarily.
These three situations describe common problems for image quality and patient dose. ISS, Inc. can assist you in maximizing image quality while keeping patient dose as low as reasonably achievable (ALARA). For more information access our recent white paper.