Thank you for joining our webinar today at PCAA on Gentle Imaging in Pediatric Trauma. Today we have Dr. Ai with us. She is the Chief of Division of Pediatric Radiology at Dayton Children's. She has practiced pediatric radiology at Dayton Children's since 1988. She is board certified in diagnostic radiology with certifications of added qualifications in pediatric radiology by the American Board of Radiology. She completed her residency at Tulane University of Medicine in 1987 and her fellowship at Cincinnati Children's in 1988. Dr. Ai is an Associate Clinical Professor at the Wright State University Boonshot School of Medicine. Welcome, Dr. Ai. Next. Thank you for joining us today at PCAA on Gentle Imaging in Pediatric Trauma. Please make sure you call in to the conference line. The audio portion on those two webinars should provide you the PIN access to call in. Registration includes one phone line. Next. Check your email for handouts. All attendees are muted by default. At the very end, we're going to have question session. Please use the question tab in the control panel to submit a question, or you may raise your hand, and we will unmute you at that time. Next. At the very end of the presentation, please follow the instructions for SurveyMonkey, and this will give you access there to get your CEs or CMEs. It does appear we're having a few connection problems with some of our users. As a reminder, this is being recorded, and we'll be able to get it out to you shortly after that. Next. Thank you, Jennifer. As you said, my name is Beth. I am a pediatric radiologist here in Dayton. Also part of this presentation was from Molly Osterhage, who's a fourth-year medical student at Wright State University School of Medicine. She helped us with the quality improvement project in comparing CT radiation exposure in pediatric trauma patients. Also, Dr. Jeffrey Pence is a pediatric surgeon with 32 years of experience. He is board certified by the American Board of Surgery with additional certifications in pediatric surgery, trauma surgery, and surgical critical care. He is the director of the trauma service at Dayton Children's Hospital. He received his medical degree at the Medical College of New York and trained at the University of Colorado Health Services. We are also friends and colleagues of Dr. David Meagher, the former director of trauma services at Dayton Children's. Dr. Meagher is the trauma surgeon who encouraged us to participate in today's seminar. I have no disclosures. I do not receive any compensation for this presentation or from any outside sources. We're going to go ahead and vote. Please select your role in the trauma program. I'm going to go ahead and close. And it looks like we have 65 percent nurses, 12 percent physicians, 8 percent CT technologists, and 15 percent others. That's a nice selection for today's presentation. Go ahead, Dr. I. So, this is a list of the topics I was asked to address for this conference. As you can see, it's quite extensive, and I have a limited amount of time. As the topics have a fair amount to do with physics and radiation exposure, I will stick to the basics. First, I'll make a disclaimer from the beginning. I'm not a radiation physicist. I make all due apologies to those who are actual experts in radiation physics. I'll keep my presentation to a very basic level and one that I can understand. As a pediatric radiologist, I do the best I can to balance the patient care needs of our trauma service within the guidelines of the American College of Surgeons and appropriate patient imaging care within the guidelines of the American College of Radiology in order to diagnose and care for pediatric patients as accurately as possible and in a timely manner, keeping in mind the needs and comfort of our patients and families. As all of you know, that's a challenging balance to keep. Some of the topics we're going to discuss today are radiation exposure and pediatric trauma evaluation. I'll give a brief explanation of radiation exposure to children. We'll do a comparison of radiation exposure from various imaging exams. We'll discuss vendor-specific CT settings. We'll compare pediatric trauma CT exposures from regional hospitals in our area. I'll make a comment on hand scanning. I'll give a case example of that. We'll discuss briefly the use of contrast in pediatric trauma patients as well as the use of sedation in pediatric patients and then a brief discussion of what to scan before transferring a patient. Can you do next for me? Much of the information I'm presenting today is available through the Image Gently website. The Image Gently collaborative effort was begun 10 years ago to raise awareness of radiation exposure to children from diagnostic imaging. It has been tremendously successful in raising awareness and providing useful information. I encourage all of you who are attending the seminar to visit the Image Gently website for a great source of information for providers, patients, and family regarding radiation exposure to children from diagnostic imaging. I also found the United Nations Environment Program on Radiation Effects and Sources to be another useful source of information. To address the types of radiation we're exposed to, we need to review the electromagnetic spectrum. I know this sounds like we're getting into physics now, so hang on. On the far right of the spectrum, we have electromagnetic radiation energy with long wavelengths and low energy from electric power poles. Next we have AM radio, and after that, FM radio. Remember that radio frequency, RF frequencies used in MRI are in the FM radio range. We are all comfortable with using energy from microwave ovens to heat and cook our food. That's this energy range. And please recall, in the infrared spectrum, we're familiar with radiant warmth to warm ourselves and our food. When we move into visible light, an ultraviolet light range of wavelengths and energy, please recall exposure of UV radiation can lead to sunburn, and prolonged exposure to UV radiation to the skin is associated with an increased rate of skin cancer. You see how we've crossed into the ionizing level of energy. As we move into shorter wavelengths and higher energy, we cross into the ionizing range of electromagnetic energy. This is the range of energy which is high enough to cause ionization of atoms. Ionization of atoms has potential to damage tissues as well as the potential to cause genetic damage. Today, we're going to focus on the range of medical X-rays. X-rays are on the order of 10 to the 17th to 10 to the 19th hertz, or cycles per second. Radioactive sources in nuclear medicine and at the nuclear power level are even higher energy. I'll give you the next slide. In order to discuss the biology of ionizing radiation effects, we need to look at the penetrating power of various types of radiation. Alpha particles emitted from radioactive sources do not have enough penetrating power energy to penetrate the hand, so they cause radiation exposure to the skin without the ability to image the hand. Beta particles emitted from radioactive sources can penetrate the hand, but will not penetrate aluminum. The energy in X-rays and gamma radiation, such as nuclear medicine, have adequate energy to penetrate the body to create an image that can be stopped with a thin or thick layer of lead. The energy in neutrons, such as from nuclear energy plants, passes through even thick lead, which can be stopped by thick concrete. So in medical imaging, we can engage the energy of X-rays to make diagnoses, and we can control the energy with thin layers of lead to keep ourselves and our patients safe. It's such an easy question to ask. How much radiation did the child receive from a CT scan? What's really implied by this question is, how much risk of radiation damage was this child exposed to? To answer the question truthfully, we need to consider at least four things. How much radiation was used? How strong was the radiation energy used? How large was the patient's body part? And how radiation sensitive was that tissue that was irradiated? In order to compare the radiation exposure and dose to our patients between CT scanners and between institutions, we need a consistent unit of measurement. Absorbed dose is a physical measurement of the amount of radiation energy absorbed by a kilogram of tissue. It's measured in the unit of gray, which is named for the English physicist, Harold Gray. But this radiation dose report does not give the full picture, because the same radiation dose from lower energy alpha particles does not cause the same amount of damage as the radiation dose from higher energy gamma rays. To compare absorbed dose of different types of radiation, they need to be weighted for their potential to cause certain types of biologic harm. This weighted dose determined by the energy of the type of radiation used is called equivalent dose and is recorded in the unit of Siebert, named for the Swedish scientist, Rolf Siebert. Another consideration is the sensitivity of various body parts to the effects of ionizing radiation. We have learned, mostly from studies of survivors of the nuclear bombs in Japan, that an equivalent radiation dose to one part of the body may be more likely to be associated with greater risk of cancer or genetic damage. The more radiation sensitive organs are breast, bone marrow, thyroid, skin, gonads, and brain. Thus, in order to compare doses when different tissues and organs are irradiated, the equivalent doses to different parts of the body are also weighted. This results in an effective dose, which is also expressed in Siebert. It's important to remember the effective dose is an indicator of the likelihood of cancer and genetic effects following lower radiation doses as seen in diagnostic imaging. It's not intended as a measure of severity effect at higher doses. In comparing CT radiation doses, we also need to know the size of the patient relative to the size of the standard used to measure the radiation dose, and I'll explain that more in a minute. So, in summary, we have a basic radiation dose measurement of all types of radiation, the absorbed dose. We have a dose weighted by the type and energy of the radiation, the equivalent dose. And we have dose that is an indication of the likelihood of cancer and genetic effects caused by lower ionizing energies used in diagnostic imaging called the effective dose. I know this is complicated, but let's keep moving on. Let's look at the sources of radiation exposure in the population we're concerned about. I'm only considering the radiation exposure from diagnostic imaging. I'm not going to include the natural background exposure from cosmic radiation due to altitude of flying in a helicopter during transfer. I'm also not considering the natural radiation exposure from the makeup of our building blocks, bricks, nor from potential sources from radon in our building. Our pediatric trauma patients are exposed to ionizing radiation from three main sources in diagnostic imaging, conventional radiography, CT scans, and fluoroscopy. A seriously injured pediatric patient often has conventional radiographs of the chest, spine, pelvis, and extremities as determined by physical exam and clinical history. They often have CT scans of the head, abdomen, and pelvis as determined by physical exam and clinical history as well. Fluoroscopy is typically used for orthopedic treatment of skeletal injuries. The next polling question, please go ahead and vote. Okay, as voting's closed, we're going to just go ahead and share. We're showing 25% say chest x-ray, 29% say flying, and 46% say neither. And, Dr. I, what is the correct answer? The correct answer would be neither. This is a list of relative values of radiation exposure, which range from over a thousand millisieverts per radiation therapy to a tiny radiation dose of 0.01 millisieverts to dental x-ray. The conventional chest radiograph is typically about 0.1 millisieverts, which is about the same as flying for 20 hours. A typical CT of the abdomen is about 10 millisieverts. From this, we can see that CT scans are the gorilla in the room compared to conventional radiographs. For every one CT of the abdomen, a patient can receive an equivalent dose from roughly 100 conventional radiographs. The minimal requirement for reporting patient CT dose are called CT dose index and dose length product. You'll find these reported on all CT scanners and are usually indicated on the CT dose report page. In order to understand the radiation dose that the patient received, we also need to know the reference phantom size. So, what does that mean, a CT phantom? This is a picture of two standard CT phantoms. They are made of acrylic and are 16 centimeters or 32 centimeters in diameter. They are made to roughly estimate the average adult size head and torso. Radiation sensors are placed inside the phantom and the radiation exposure from the CT scanner is measured for a specific CT protocol, such as a head CT or body CT. The acrylic does attenuate the X-ray beam in a standard fashion and to a greater extent than air. The radiation exposure at the outside of the phantom is higher than that measured in the center of the phantom. Air does not attenuate the X-ray beam. So, the radiation physicist makes measurements of the radiation exposure by a specific CT scanner during a specific type of protocol. That measurement is used as a reference of what a patient may have received during the use of that CT protocol on that CT scanner. So, what about the patient who's actually smaller than the phantom? The radiation exposure used to image a small child's torso is reported according to the 32-centimeter torso phantom. The pediatric patient who is smaller than 32 centimeters of acrylic does not have enough soft tissue to attenuate the X-ray beam as a larger patient. The smaller pediatric patient actually received a larger dose than what was recorded inside the 32-centimeter phantom. Radiation dose equivalent is used to account for the patient's size and or age. Because our head size does not change dramatically after the age of two years, age-specific dose equivalent can be used as a more accurate estimation of radiation dose to the head and neck for pediatric patients. A correction factor called the K-factor can be applied to the reported dose to more accurately estimate the radiation dose to smaller patients. The K-factor is determined by physicists measuring exposure to pediatric size models. The size-specific dose equivalent can likewise be used to estimate radiation dose to the torso in children. The patient's actual cross-sectional width and depth is measured by the CT technologist and a correction factor, again the K-factor, is determined from established guidelines. All of the CT vendors have developed pediatric settings based on protocols developed by pediatric experts. Most are based on patient age or size. When a CT scanner is purchased and installed, many people work together to ensure the scanner is working properly and performing to the standards acceptable to that institution. The CT application experts work with the radiologist to determine the radiologist's desire to balance the level of image noise and image detail with the radiation dose used, as well as to discuss the use and timing of IV contracts. The radiation physicist measures the actual radiation output from the scanner, as well as the scanner's ability to distinguish CT density and the resolving power of the scanner. The CT application expert works with the CT technologist and trains them to use the scanner appropriately. Forgive me for my simple analogy for CT radiation dose as microwave popcorn. To me, this analogy is easy. Our goal is to have as much perfect popcorn as possible without burning it. The problem is that microwave popcorn products vary by size and manufacture, just as the microwave oven varies by wattage. The popcorn has recommendations on how to pop the product based on the wattage of the oven and by the time. I don't know about you, but I don't know the wattage of my own microwave. Some microwave ovens even have popcorn settings. I follow the instructions, but I still override the setting to get as many kernels popped as possible without burning. The actual radiation dose a specific patient receives is determined not only by the CT scanner, but by many individual decisions at that institution. The first decisions are made by the providers ordering the scans. The radiologists play a part in determining how a specific type of CT is to be performed. The CT technologist chooses the appropriate CT protocol on the CT scanner, prepares the patient for the CT scan, and performs the scan. Our goal is a diagnostic study without overexposing the patient. The problem with CT radiation exposure is that overexposure to the patient does not have an immediate visible consequence, unlike our popcorn analogy. Overexposure in the CT scanner provides excellent images with no immediate observable effects on the patient. Here is our opportunity to improve patient care. For our quality improvement project, we performed a retrospective chart review of pediatric trauma patients in our trauma service who received CT scans between January 2017 and December 2017. The patients had CT scans at Dayton Children's as well as 26 regional non-pediatric hospitals. There were 268 pediatric patients who received a total of 380 CT scans. Most of the scans were of the head, 60%. And abdomen and pelvis CT was another 17%. Approximately 65% of the patients were male, and the average age was 6.2 years. Here's what we found. The radiation dose, here, and the effective dose for head CT studies were lower at the Children's Hospital compared to the outside institution, and the difference did reach significance. These are whisker plots, and the mean is here, and this is the variability in the dose range for the Children's Hospital versus the outside hospital. And then for the effective dose, again, the mean was smaller and the range of variability was higher. Similarly, the radiation dose and effective dose for C-spine CT studies were also lower at Dayton Children's than the outside institutions, and the difference did reach significance. Again, here's the effective dose and the radiation dose, comparing the Children's Hospital to the outside hospital. Look at the range of variability of the dose. The radiation dose and effective dose for abdomen and pelvis CT were lower on average at the Children's Hospital, but the difference did not reach significance. Note, again, the tremendous variability in radiation dose at the outside institutions. The number of scans was relatively small, and the variability of the dose was large. So, we demonstrated similar findings as reported at many other sites. Even though much progress has been made to raise awareness of radiation exposure from CT in children, there continues to be room for improvement. We need to continue to educate and encourage patient care teams to keep radiation dose as low as possible. We need to continue to educate and encourage patient care teams to keep radiation dose patient care teams to keep radiation dose as low as reasonably achievable. That's the ALERA principle. In order to compare results, we encourage the use of a standard radiation dose estimate, and we also recognize the need to educate providers on how and when to perform CT scans in traumatized children, and when alternate imaging might be as good or better. PAN scanning is a term used to describe performing CT scans through multiple body parts based on adult's clinical decision-making pathway without regards to the patient's physical exam or likelihood of significant injury. It can also be applied to repeat scanning through the same body area during arterial, portal venous, and delayed phase of IV contrast enhancement. It is rarely of clinical value in pediatric trauma, and it can double or even triple the radiation dose. In pediatric abdominal trauma, portal venous phase is adequate. Here's an example of PAN scanning in a 16-year-old male with history of neck pain after a motor vehicle accident. He had no other complaints or significant history and no findings on physical exam. He underwent CT of the head, face, cervical spine, thoracic spine, and lumbar spine without IV contrast, and then he had CT of the chest, abdomen, and pelvis with IV contrast. He was transferred to our hospital for possible C1 fracture. On review of the imaging, the abnormality was found to be an unfused ring of C1, which is a normal variant. By the next morning, his neck pain had resolved, and he had no new symptoms or findings, and he was released home. I would argue that in his case, a cervical spine series could have been performed and would have been normal. He could have been observed for 24 hours, and where a solution of symptoms and with no new symptoms, he could have been released. If he still had neck pain, an MRI of the cervical spine could have been performed with no additional radiation. Even if it was necessary to perform CT of the head, the CT of the facial bones was unnecessary without symptoms or clinical findings. Likewise, it was unnecessary to scan the thoracic and lumbar spine separately and then re-scan the same area with contrast-enhanced CT of the chest, abdomen, and pelvis. The thoracic and lumbar spine can be reformatted from the CT of the chest, abdomen, and pelvis. His total reported CT dose was 3,657 milligrams. It could have easily been reduced by nearly two-thirds, or 1,252 milligrams, by just performing CT of the head, abdomen, and pelvis, or his dose could have even been as low as less than 0.5 millisieverts with cervical spine films and observations. I believe this is a good example of the importance of education and care for the health of our patients, and the importance of education and team effort to reduce the reflexive ordering of CT scans, or pan scanning, to be sure that we haven't missed anything. We need to help ED providers to feel justified in ordering the appropriate CT of the body area that is clinically indicated at the time. We also need to give both positive and negative feedback to the original ED providers. With coordinated efforts as trauma teams, we can make this happen. IV contrast is needed for CT evaluation of trauma to the abdomen. Contrast enhancement is used to detect and grade injuries to the liver, spleen, and kidneys. Pancreatic injuries are also detected with IV contrast. IV contrast is also useful to detect the rare case of vascular injuries with dissection or active bleeding. Enteric contrast, given by mouth, is not needed and is even contraindicated in trauma patients. The use of enteric contrast causes delay in getting a scan completed and increases the risk of vomiting with pulmonary aspiration during the scan or during intubation if it is eventually needed. Sedation is rarely used in CT for pediatric trauma patients. The CT technologist is the most important leader in getting the patient through the CT scan without needing sedation. The CT technologist explains the process to the patient, family, and trauma team. The CT tech uses a variety of distraction techniques, including things such as light, music, toys, and parents. Mobilization techniques are also very helpful. Safe pediatric sedation requires a competent sedation team comfortable sedating children. In my opinion, the pediatric trauma patient should have a non-contrast CT head, as indicated by clinical history or exam. If the patient has injuries to the face, a CT of the face can be obtained at the same time in order to avoid a return visit to the scanner after transfer. CT of the abdomen and pelvis can be obtained if there's appropriate history and clinical findings. It should always be performed with IV contrast. If it is not possible to give the IV contrast, the CT of the abdomen and pelvis can wait until after transfer. CT of the chest is almost never needed in pediatric trauma. A chest radiograph can be obtained to evaluate for pneumothorax or hemothorax, which is such that it assesses the position of the endotracheal tube and the nasogastric tube. Additional radiographs of the pelvis, spine, and extremities can be obtained with appropriate history or findings. If the patient is definitely going to be transferred, the rest of the trauma imaging can be obtained after arrival. Thank you, Dr. Ives. Go ahead and open time for questions. Go ahead and raise your hand or ask your question. The first one is, with trauma society guidelines for evaluation of non-continuous spinal fractures, how is hand scanning avoided in patients with presumed cervical spine fracture? I'm sorry. Could you read that again, Jennifer? With trauma society guidelines for evaluation of non-continuous spinal fractures, how is hand scanning avoided in patients with presumed cervical spine fractures? Let me look into that further because I don't know the guidelines off the top of my head, and the PCAA will get back to you by email. Dayton Childress, go ahead and ask your question. Go ahead, Diana, and ask your question. Are there any other questions? We'll give another few seconds. Looks like no other questions. If you do have further questions, please email myself, Deb Myers, at CCA. And we will contact Dr. I for those questions. And there is another one that just popped in. With concealed trauma histories of child abuse and the risk of death before two years old, benefits of loss of imaging outweigh risk. I'm sorry. Was that a question? Yeah. The question is, with our child abuse cases under two and the risk of death, which is better, the benefits of loss of imaging outweigh the risk of undetecting an injury in our child abuse population under two before they're talking? Absolutely. Imaging is a very important role in saving the lives of abused children. Typically a child in the ED would get a head CT. And with abnormal blood work, such as liver enzymes, we would CT the abdomen and pelvis. Then we would do a skeletal survey, which is going to pick up the remainder of the injuries. If they had a significant abusive head trauma, we would do MRI of the cervical, thoracic, and lumbar spine after the child was stabilized. Would you consider interior contrast for suspection of bowel injury at perforation? I would not, in the emergency trauma setting, consider that important. In the urgent setting, we would CT the abdomen and pelvis, and we would look for the CT findings associated with bowel perforation. We would then observe the patient over the next 24 to 48 hours and determine whether additional imaging of the bowel was needed, or if the patient was not improving, whether laparoscopic surgery would be appropriate to evaluate the area of concern on the original CT. Next question. What do we say when providers say no to recommended scans? I'm sorry. What do we say when providers say no to the recommended scan? Yes. I don't understand the question. This member is having trouble when there's a disconnect, maybe, with the ER provider, with the radiologist, with the trauma surgeon, and they're saying we don't need any more scans based on the recommendations. So, from the radiologist's perspective, what do we say if the provider wants additional imaging? Or, if you would like additional imaging and the provider is saying no. Well, the provider is the one that's evaluating the patient, has seen the actual patient, and has the clinical history. So, if I felt there was additional imaging that was indicated, I would have a conversation with the provider to express my concern and then hear in conversation why that was not a concern for them. I think it requires direct conversation. Okay. And, in clarification, in child abuse, they get lots of pushback, even with the 1 to 6 to 10 risk of missing occult head trauma. The ED provider gets pushback. I'm sorry. Yes. In child abuse, if they're saying we shouldn't do it because we're trying to conserve radiation, but you just also mentioned that in our child abuse patients, we should really rule things out. Right. When you have a child, infant, less than 2, presenting to the emergency department or a provider in which the physical exam does not match the clinical history or you have a suspicion of abusive head trauma, a CT scan of the head is absolutely mandatory to save that child's life. Thank you. There are never easy answers to when to perform CT or not. It's always a judgment of risk versus benefit. And in the case of abusive head trauma and a child that can't tell you what actually happened to them, we have to be the advocate for the infant and, yes, expose the child to CT if needed. One last question. Can you discuss any dose reduction techniques, especially in head and neck? Dose reduction techniques for the head and neck, we angle the gantry for the head CT to avoid radiation to the orbit because the lens of the eye is relatively radiation sensitive and we want to try to avoid the thyroid gland. So we don't necessarily include the orbits with the head CT. We just do the head CT. As far as CT of the neck, just scanning the area that is important, not over-scanning into the upper chest or lower head to limit the area of coverage to what is needed. MRI is the alternate imaging if you can wait for when the MR scanner is available and if the patient can cooperate, you can have quite a bit of MR inflammation on the spinal cord and the ligaments. Those would be the things that come to the top of my head as far as reducing radiation exposure for head CT and cervical spine. Thank you for those answers. At this time, I'd like to conclude the webinar today and thank Dr. I for a great presentation and wealth of information provided today as you digest this information. If you have any questions, please go ahead and email or call our office and I'll get those questions forward to Dr. I. Please don't forget to complete the evaluation following the program so we may continue to improve our offerings. Thank you again today for joining us in the presentation on Gentle Imaging for Children. Thank you very much and have a great afternoon.

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