chapter 24

Imaging DecisionMaking Strategies and Considerations Parul B. Patel, MD, MPH, FAAP Steven E. Krug, MD, FAAP

Objectives

Chapter Outline

Summarize the radiation safety concerns in pediatric emergency care.

Introduction

1

2

Radiation Safety Concerns in Pediatric Emergency Care Developing Imaging Guidelines for Children Summary

Compare the benefit and risk of imaging modalities.

3

Summarize the imaging decision making strategies and considerations in pediatric emergency care.

Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

1 CASE SCENARIO

A 3-year-old girl presents to the emergency department (ED) with a history of head trauma 3 hours ago, when she fell from a stool and struck her occiput on a hard floor. There was no loss of consciousness, but she vomited twice. Her parents have noted a large, tender swelling over her occiput. She is subdued and cooperative but not drowsy. She has experienced headaches for the past 8 days. She has a headache now, but it not severe. She has been treated with acetaminophen (paracetamol) and ibuprofen, which seem to help her headaches. Vital signs on examination are as follows: temperature, 37.0°C (98.6°F); pulse, 85/min; respirations, 30/min; and blood pressure, 80/55 mm Hg. She is of average size and build. She is quiet and cooperative. Her parents point out that she is normally more active than this. Her head shows some tenderness over her occiput, with moderate swelling and bruising. No deformity is palpable. Eyes show equal and reactive pupils. Extraocular movements are full. She is cooperative, and a funduscopic examination reveals sharp optic disc margins and no retinal hemorrhages. T y mpanic membranes are normal. No bruising is evident elsewhere. Her nose is clear. Her mouth examination results are normal. Her neck is nontender and supple, with a full range of motion. The results of heart, lung, abdomen, and back examinations are normal. She ambulates normally. Her reflexes are normal.

24-3 Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

1 C O N T. CASE SCENARIO

She has some risk of serious brain injury, but her risk appears to be low. Taking an antiplatelet agent such as ibuprofen before the head trauma episode might increase her risk of intracranial hemorrhage. With her prior history of headaches, there are other diagnostic possibilities of concern. 1. Should a brain imaging study be performed in the ED? 2. Should brain imaging include computed tomography (CT) and magnetic resonance imaging (MRI) as options? 3. What should the parents be told during the consent process for CT and/or MRI? 4. Are these options and decisions likely to change over time (ie, this year vs 5 years from now)?

Introduction There have been extraordinary advances in medical imaging, such as ultrasonography (US), CT, MRI, and positron emission tomography (PET). Both CT and US are now available in nearly every ED. Imaging modalities, particularly CT, should be used judiciously in pediatric care, especially when considering the safety concerns of radiation exposure.

Radiation Safety Concerns in Pediatric Emergency Care The value of CT as a diagnostic tool has been well recognized by health care professionals. Published data confirm a remarkable growth in the use of CT, as much as 600% since the mid-1980s, with more than 60 million studies obtained annually in the United States and an estimated annual utilization rate in children ranging from 4 million to 7 million.1–3 This growth has been driven not only by increasing availability but also by other contributing factors, including expectations of referring physicians, patients, and families, emergency care physician concerns for medical risk, efforts to improve throughput in overcrowded EDs, faster scanners, reduced need for sedation, and 24-4

limited experience in the clinical assessment of ill and injured children.4,5 In the midst of rapid growth in the use of CT has come an awareness that ionizing radiation from medical imaging can place patients at a significant lifetime risk for the development of fatal cancer.1–3,6–8 This risk appears to be especially great in children for the following reasons: • Tissues and organs that are growing and developing are more sensitive to radiation’s harmful effects. It has been estimated that children might be 10 times more radiation sensitive than adults. • The oncogenic effect of radiation can have a long latent period that varies with the type of malignant neoplasms. Infants, children, and younger patients have a much longer remaining life expectancy in which to manifest the potential oncogenic effects of radiation compared with older adults. • In the case of CT, the radiation exposure from a fixed set of CT parameters results in a dose that is relatively higher for a child’s smaller cross-sectional area compared with an adult.2 The literature has targeted CT use due to its relatively large dose of radiation. Computed tomography accounts for 10% to 15% of all

Imaging Decision-Making Strategies and Considerations Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

TABLE 24-1  Estimated Medical Radiation Doses for Various Imaging for a 5-YearOld Child Imaging Area

Effective Dose, milliSievert (mSv)

Equivalent No. of Chest Radiographs

3-View ankle

0.0015

1/14

2-View chest

0.02

1

Anteroposterior and lateral abdomen

0.05

2½

Technetium Tc 99m radionuclide cystogram

0.18

9

Technetium Tc 99m radionuclide bone scan

6.2

310

FDG PET scan

15.3

765

Fluoroscopic cystogram

0.33

16

Head CT

4

200

Chest CT

3

150

Abdomen CT

5

250

Abbreviations: CT, computed tomography; FDG PET, fluorodeoxyglucose positron emission tomography. Brody AS, Frush DP, Huda W, Brent RL, American Academy of Pediatrics Section on Pediatric Radiology. Radiation risk to children from computed tomography—clinical report. Pediatrics. 2007;120:677–682. Data were provided by R. Reiman, MD (Duke Office of Radiation Safety [www.safety.duke.edu/RadSafety], written communication, 2006).

imaging studies ordered, yet 45% to 60% of all medical radiation exposure (Table 24-1). Although the true risk might not yet be known, cancer risk estimates, which represent extrapolations from studies of the survivors of the Hiroshima atomic bomb exposure, range anywhere from 1 in 1,000 to 1 in 3,000 for a CT scan.6–8 It has been estimated that as many as 1% to 2% of all cancer in the United States today can be attributable to medical imaging.1 The risk for cancer can be especially great for the youngest and most medically complex pediatric patients, who experience a disproportionate amount of imaging studies. Potential cognitive harm to the developing brain of infants by cranial ionizing radiation has been demonstrated in a Swedish study that found reduced cognitive performance in young adults who sustained cranial irradiation as infants compared with controls. It is physiologically accepted that ionizing radiation to growing cells and tissues is harmful; thus, although this study mainly focused on cranial irradiation in infants, the brain of children is similarly growing and developing, placing it at risk for similar cognitive harm by cranial irradiation. This study

suggests that disclosure of the potential harm due to cranial CT in infants and children should include cancer risk and cognitive harm risk.9 Clinicians bear a responsibility to use diagnostic testing with discretion because the diagnostic yield of medical imaging in children and the associated risks can be different from that in adult patients. Informed consent principles require that clinicians discuss the benefits and risk of harm with patients and parents in ordering diagnostic studies such as CT scans and plain radiographs. Studies indicate that patient families will welcome such discussions regarding diagnostic and therapeutic interventions, including medical imaging.10 Once informed, they can accept alternative approaches, such as observation over imaging. Informing patients and their families and partnering with them in medical decision making are fundamental principles of patient- and family-centered care and will add significantly to efforts to improve patient safety.11–13 Families and patients should be encouraged to ask questions about the risks and benefits of CT and other imaging techniques. Physicians should become familiar with the imaging Radiation Safety Concerns in Pediatric Emergency Care 24-5

Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

practices within their hospital and, through collaboration with clinical leadership of the radiology department, ensure that imaging equipment and protocols support reduced radiation exposures, such as ALARA (as low as reasonably achievable), for children. Many hospitals that provide care for children do not use ALARA settings and thus have unnecessarily higher radiation exposures.14 The following principles of the Image Gently Campaign15 (developed by the Alliance for Radiation Safety in Pediatric Imaging) should be embraced by all health care facilities serving children: • Reduce the amount of radiation used. • Scan only when necessary. • Scan only the indicated region. • Scan once; multiphase scanning is usually not necessary in children.

Developing Imaging Guidelines for Children Perhaps one of the best ways to reduce radiation exposure due to diagnostic imaging is to consider the diagnosis in question, the pretest probability of the diagnosis, the clinical importance of the diagnosis, how the test result will alter the plan of care or the patient’s outcome, and whether there are any alternatives to imaging, such as clinical observation, or alternative imaging modalities, such as US or MRI. These strategies can be best determined through consultation with radiologists and/or pediatric medical and surgical subspecialists. There are additional factors that limit access to optimal imaging technology. It is well accepted that the medical resources immediately available on weekdays are less available on evenings, nights, and weekends. Although US, MRI, and CT services are in full operation during standard business hours, availability is reduced after hours. Very large hospitals can afford to maintain around-the-clock technician availability, but smaller hospitals have limited availability, which can create a barrier when attempting to order these studies after hours. Even for larger hospitals, technicians trained in safety and optimal image acquisition for each of these advanced imaging modalities are in limited supply. 24-6

As a means to optimize imaging decisions and use, institutions should ideally develop guidelines or clinical decision tools to direct the use of diagnostic testing in children for these scenarios; however, these guidelines are difficult to compose, availability is different during business hours vs after hours, indications and diagnostic yield from these imaging modalities change with time, and the clinical indications are numerous, age dependent, and severity dependent, making the number of combinations and permutations enormous. There are intermediate and incomplete areas in nearly every chief condition, and there will be many patients who will not fit within a care pathway. The difficulties of creating a practice guideline are exemplified by the attempt to create guidelines for which patients require ankle imaging. The Ottawa ankle rules are well validated, but it took much longer to gain experience with these rules in children. It took great effort and numerous publications for clinicians to accept these rules for plain ankle radiography, a highfrequency imaging study with minimal harm. When considering the development of clinical pathways to guide imaging decisions in children, it might be helpful to do so by body system and indication. Using this approach, Table 24-2 summarizes the following clinical and imaging considerations and recommendations for imaging strategies. Because patient safety and care quality should be a priority for all health care professionals caring for children, institutions should ideally collaborate with pediatric primary and subspecialty care physicians and medical imaging specialists to develop clinical pathways as a means to optimize pediatric care.

Head and Brain The head and the brain deserve special consideration. In addition to cancer risk, the risk of cognitive harm must also be considered. For severe head trauma in a critical patient in need of immediate imaging, only CT can provide a head and brain image rapidly, despite the potential detriment of radiation exposure. For less severe cases in which time is not a critical factor, the speed advantage of CT is no longer as important. The multicenter minor head injury study from

Imaging Decision-Making Strategies and Considerations Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

the Pediatric Emergency Care Applied Research Network offered a decision tool that might result in better use of CT.16 Also useful in reducing unnecessary CT use are the decision rules from the National Emergency X-Radiography Utilization Study II17 and the Canadian Assessment of Tomography for Childhood Head Injury studies.18 For patients who do not clearly require urgent imaging and yet in whom a brain imaging study is still clinically justified, both CT and MRI are capable of imaging the brain and have advantages and disadvantages. Because CT is fast, it is not likely to require sedation. Because MRI is slow, it will require intravenous sedation in uncooperative children. Sedation poses additional barriers, depending on hospital requirements and practice standards, such as a credentialed clinician who can administer the appropriate level of sedation and a sufficient fasting (nothing by mouth) period. Computed tomography poses radiation exposure risk, whereas MRI has a high magnetic field risk but no ionizing radiation exposure. Although CT might be better at identifying small amounts of bleeding, these are not likely to benefit from neurosurgical intervention. In an older cooperative patient who does not require sedation, MRI comes out ahead. For younger patients, the tradeoff between radiation exposure risk and sedation risk, as well as resource availability, must be considered. For children with hydrocephalus managed with a ventriculoperitoneal shunt (or other variation), symptoms of headache, vomiting, and lethargy are common symptoms that suggest the possibility of shunt malfunction. For an acutely ill or unstable child (eg, concern for severe increased intracranial pressure and altered mental status) for whom a rapid diagnosis is warranted, head CT is still the best imaging modality. For children who are stable but in whom a shunt malfunction still needs to be ruled out, exploring other options for imaging is prudent because these children have likely experienced multiple brain imaging studies in their lifetime. A CT of the ventricles (not the entire brain) offers a focused assessment of ventricle size at a lower radiation exposure dose (40%–60% lower) than a standard CT of the brain. Although not sufficient to evaluate the brain parenchyma, it gives

sufficient information regarding the ventricles. A rapid MRI, which similarly focuses on the ventricles and does not image the entire brain, can provide sufficient information on ventricle size. Unlike a standard MRI, which is fairly lengthy, these studies can be completed in as little as 2 minutes (actual scanning time) and can preclude the need for sedation for young children. When cranial tumors, vascular lesions, or other brain disease is being considered, CT is often the first test ordered, but if the child is stable and there is no need for sedation (or if sedation risk is less than radiation risk), then MRI should be considered before obtaining a CT. The imaging study that provides the best information is MRI, which offers higher sensitivity and discrimination for most disease, and many children whose conditions are initially diagnosed with a CT ultimately require an MRI.

Neck For neck injuries, CT of the neck is a common practice in adult trauma care that has been extrapolated to children, but for most pediatric trauma patients, plain radiographs or clinical evaluation is sufficient to screen the cervical spine.19 Computed tomography should not be the first-line imaging modality in assessing children for cervical spine injuries.20,21 Computed tomography or CT angiography might be indicated for the rapid assessment of airway or vascular injuries in patients with penetrating trauma to certain areas of the neck. Decisions to perform CT of the neck should be well considered because the thyroid gland is highly radiosensitive. Magnetic resonance imaging is superior in assessing soft tissue disease and the spinal column. For retropharyngeal abscesses, CT has traditionally been the imaging study to best distinguish an abscess requiring drainage versus a phlegmon that is not amenable to surgical drainage; however, this tradition deserves reconsideration because MRI should have the same capability without radiation exposure.

Chest Plain chest radiographs are sufficient to identify most chest conditions. Computed tomography and/or CT angiography might be the optimal Developing Imaging Guidelines for Children 24-7

Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

study to evaluate penetrating traumatic injuries but should not be the primary modality in the evaluation of routine blunt trauma. Computed tomography has utility in evaluating a chest mass and evaluating patients for aortic dissection or great vessel and pulmonary vascular disease. Echocardiography is highly diagnostic to assess cardiac function and anatomy. The diagnostic utility of chest radiographs is limited in conditions such as bronchiolitis22 and asthma, although pneumonia, a mediastinal mass, or a pulmonary vascular anomaly can occasionally be identified from imaging performed in patients suspected of having bronchiolitis or asthma. A chest radiograph is not unreasonable in first-time wheezing episodes or in an asthmatic patient with a fever for whom the results might alter clinical management. A chest radiograph might be indicated for severely ill children (eg, respiratory failure) or for those who do not respond to treatment to rule out other diseases.

Abdomen The abdomen is frequently initially evaluated using plain radiographs, but these radiographs are rarely diagnostic. Occasional diagnostic findings include a bowel obstruction, an appendicolith, the target and/or crescent signs of intussusception, and a mass effect. In most instances, an additional imaging study is still necessary. For abdominal trauma, CT is an extremely valuable tool for identifying the extent of injury, particularly to solid organs. There might be an evolving role for focused abdominal sonography for trauma (FAST) as a screening tool in determining the need for operative intervention; however, FAST scanning is not sensitive enough to reliably exclude intra-abdominal injury.23,24 Clinical prediction rules designed to identify those children with blunt abdominal trauma at low risk for intra-abdominal injuries might serve to reduce unnecessary CT use.25,26 For appendicitis, CT has been the imaging modality of choice to confirm the diagnosis of acute appendicitis in many centers, although this diagnosis can be made clinically without imaging. There is a growing trend to use US as the initial imaging study in children. Sensitivity 24-8

is often limited by the patient’s body habitus and the technician’s skill. Pathways that stage US examination before CT have supported the use of US in children. In one study, the sensitivity, specificity, negative predictive value, and positive predictive values of the staged USCT pathway were 99%, 91%, 99%, and 85%, respectively; such an approach would likely reduce CT use.27 Limited abdominal CT examination studies targeted to rule out appendicitis might serve to reduce radiation exposure by 25% to 35% compared with a standard abdominal CT.28 There is little current evidence for use of MRI in children for appendicitis, but it has been proposed as a useful alternative in pregnant patients for whom radiation is of great concern.29,30 The same concern could arguably be applied to growing children because an abdominal CT imparts a large dose of radiation. More pediatric studies might be forthcoming31,32 because adult studies have demonstrated diagnostic accuracy similar to or slightly better than CT.33,34 Surgical consultation and admission for observation, although not widely published, is a growing practice in the care of children with a low pretest probability of appendicitis and inconclusive US results. A midgut volvulus due to a malrotation can be identified by CT scan or contrast upper gastrointestinal tract study. A Meckel diverticulum is best diagnosed using a nuclear medicine scan. Intussusception can sometimes be definitively identified on plain radiographs, but it is most reliably identified on US.35 Although CT can also identify an intussusception, it should not be the imaging modality of choice. Once suspected clinically or identified on imaging, a contrast enema (air or fluid) has been the standard to confirm the intussusception and to initially attempt nonsurgical reduction.

Genitourinary For scrotal disease, Doppler US is the imaging modality of choice for the diagnosis or exclusion of testicular torsion and trauma, although this might delay timely open surgical exploration, which is necessary to prevent infarction. Ultrasonography is critical in the evaluation of ectopic pregnancy, ovarian cysts with or with-

Imaging Decision-Making Strategies and Considerations Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

out ovarian torsion, and uterine anomalies. Pelvic US in young women is complicated by the need for a full bladder and the inability to perform transvaginal scanning in nonsexually active girls.

Spine In the thoracic and lumbar spine region, MRI provides the most information on the vertebral skeleton, adjacent soft tissue structure, and spinal cord. Yet most patients do not present with symptoms serious enough to warrant MRI. Plain radiographs and CT of the spine are more easily performed, but they provide less information. These factors frequently result in a stepwise ordering approach starting with plain radiographs then proceeding to CT or MRI, depending on the clinical circumstances.

Musculoskeletal In evaluating children with an acute limp or pain in which hip disease is suspected, US should also be considered as an initial imaging modality for the evaluation of hip effusion in children. This approach can assist in narrowing the differential diagnosis and minimize unnecessary testing in children with hip pain or a limp.36,37 For most musculoskeletal sites, MRI is the best modality to evaluate for osteomyelitis, septic arthritis, or deep soft tissue infections. Ultrasonography is an excellent bedside tool for the assessment of superficial abscesses and to guide their management (incision and drainage).38 For extremity trauma, plain radiographs are highly diagnostic, but there are many known clinical circumstances in which plain

radiographs fail to visualize a fracture. Clinical follow-up or CT or MRI can be used to further define these injuries. For example, knee injuries involving nonosseous structures typically are best visualized on MRI.

Summary Pediatric health care professionals bear an important responsibility to use diagnostic testing with discretion because the associated benefits and risks are different in children. This discretion is especially prudent in the light of recent concerns regarding the potential adverse effects of ionizing radiation.

THE BOTTOM LINE • Ultrasonography is fast, has no radiation exposure, and does not require sedation, but its interpretation and accuracy are highly user dependent, and its imaging capabilities have physical limitations. • Computed tomography is fast and does not require sedation, but it results in a higher radiation exposure. • Magnetic resonance imaging has no radiation exposure, but it uses a highstrength magnet. It is slow and usually requires sedation for young children. • Advanced imaging decision making is complex, and consultation with a radiologist can be helpful.

Summary 24-9 Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

TABLE 24-2  Recommended Diagnostic Imaging Studies.a Body Area

Clinical Concern

Clinical Considerations

Optimal Study

Head and brain

Major trauma or ICP elevation

Emergent, high severity

CT

Minor head trauma

Indications for CT vs observation are controversial

Consult recent decision rules

VP shunt malfunction

Emergent, high severity

CT

VP shunt malfunction

Stable, less severe

CT ventricles or rapid MRI

Tumors, vascular lesions, other

Stable patient, low sedation risk, or no need for sedation

MRI

Penetrating trauma

Need rapid evaluation for airway or vascular injuries

CT or CT angiography

Trauma

CT should not be used as firstline routine for children

Plain radiographs

19–23

Masses

To evaluate nature and extent of masses in stable patients

US

24

Other

Suspected neck or spinal cord injuries; other less emergent conditions

MRI

Respiratory distress

Pneumonia or other severe lung conditions suspected

Plain radiographs

Respiratory infections

Suspected pneumonia but might of little use in bronchiolitis

Plain radiographs

Cardiac condition

Heart size, congestive heart failure

Plain radiographs

Cardiac condition

More definitive assessment of heart anatomy and function

Echocardiogram

Other

Chest mass or condition needing further definition, vena cava or aorta disease

CT or CT angiography

Trauma

Urgent and severe

US, CT

Trauma

Less severe

US

Abdominal pain

Staged pathways for US, limited CT, observation, clinical diagnosis, and evolving utility or role of MRI

Plain radiographs, US, limited CT, observation

Neck

Chest

Abdomen

24-10

Imaging Decision-Making Strategies and Considerations Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

Reference(s)

16–18

25

26–29

30–38

TABLE 24-2  Recommended Diagnostic Imaging Studies.a (continued) Body Area

Clinical Concern

Clinical Considerations

Optimal Study

Abdomen, continued

Bowel obstruction

Multiple causes, see below

Plain radiographs

Midgut volvulus, malrotation

CT, upper gastrointestinal tract series

Intussusception

US, contrast enema

Meckel diverticulum

Nuclear medicine scan

Scrotum

Testicular torsion

Time available

Doppler US

Gynecologic

Ovarian torsion

Time available

Doppler US

Other pelvic pain

Ectopic pregnancy, ovarian cyst, other

US

Spine

Pain or trauma

Stepwise approach is recommended

See text (pg. 24–9)

Spinal cord

Spinal cord lesion, injury

Neurologic deficit due to infection, tumor, suspected spinal cord injury

MRI

Musculoskeletal

Hip pain

Initial evaluation for hip effusion for children with limp

US

Trauma

Fracture evaluation; use validated decision rules

Plain radiographs

Trauma

Knee injury—suspected ligament or cartilage (dense connective tissue) injury

MRI—not done routinely in ED

Infection

Suspected osteomyelitis, septic arthritis

MRI

Infection

Suspected abscess

US

Reference(s)

39–41

Abbreviations: CT, computed tomography; ED, emergency department; ICP, intracranial pressure; MRI, magnetic resonance imaging; US, ultrasonography; VP, ventriculoperitoneal. a Imaging decisions are complex, and a simple recommendations table such as this cannot consider all these complexities. Clinical circumstances, availability, and consent must be considered.

Summary 24-11 Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

CHAPTER REVIEW Check Your Knowledge 1.

2.

3.

4.

5.

24-12

Which of the following diagnostic image modalities are capable of identifying appendicitis? A. Computed tomography (CT) B. Ultrasonography (US) C. Magnetic resonance imaging (MRI) D. All of the above Which of the following abdominal or pelvic diagnostic imaging modalities is the most harmful to the gonads? A. CT B. US C. MRI D. Plain radiographs The informed consent process for brain MRI of a 3-year-old child should include: A. risk of sedation. B. risk of MRI contrast. C. the option of performing CT instead. D. the option of performing no imaging study instead. E. All of the above. The informed consent process for brain CT of a 2-year-old child should include: A. potential increase in lifetime cancer risk from radiation exposure. B. potential radiation effects on the developing brain. C. the option of performing MRI instead. D. the option of performing no imaging study instead. E. all of the above. The best imaging modality to image the pediatric cervical spine in a blunt trauma case is: A. plain radiographs. B. CT. C. MRI. D. plain radiographs plus routine CT. E. each has its pros and cons, so they should be done in a stepwise fashion.

6.

Which of the following is correct regarding the radiation exposure level obtained during CT? A. All CT studies have the same amount of radiation exposure B. CT radiation exposure levels can be adjusted to minimize exposure C. X-ray exposure settings should be the same for children and adults D. Intravenous contrast lowers the risk of CT radiation exposure

References 1. Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. N Engl J Med. 2007;357:2277– 2284. 2. Brody AS, Frush DP, Huda W, Brent RL, American Academy of Pediatrics Section on Pediatric Radiology. Radiation risk to children from computed tomography—clinical report. Pediatrics. 2007;120:677–682. 3. Frush DP, Donnelly LF, Rosen NS. Computed tomography and radiation risks: what pediatric health care providers should know. Pediatrics. 2003;112:951–957. 4. Krug SE. The art of communication: strategies to improve efficiency, quality of care and patient safety in the emergency department. Pediatr Radiol. 2008;38(suppl):S655–S659. 5. Gausche-Hill M, Schmitz C, Lewis R. Pediatric preparedness of US emergency departments: a 2003 survey. Pediatrics. 2007;120:1229–1237. 6. Hall EJ. Lessons we have learned from our children: cancer risks from diagnostic radiology. Pediatr Radiol. 2002;32:700–706. 7. Brenner DJ. Estimating cancer risks from pediatric CT: going from the qualitative to the quantitative. Pediatr Radiol. 2002;32:228–231. 8. Brenner DJ, Elliston CD, Hall EJ, Berdon WE. Estimated risks of radiation-induced fatal cancer from pediatric CT. Am J Radiol. 2001;176:289–296. 9. Hall P, Adami HO, Trichopoulos D, et al. Effect of low doses of ionizing radiation in fancy on cognitive function in adulthood: Swedish population based cohort study. BMJ. 2004;328:19. 10. Larson DB, Rader SB, Forman HP, Fenton LZ. Informing parents about CT radiation exposure in children: it’s OK to tell them. Am J Radiol. 2007;189:271–275. 11. Frush KS, Krug SE, American Academy of Pediatrics Committee on Pediatric Emergency Medicine. Patient safety in the pediatric emergency care setting. Pediatrics. 2007;120:1367–1375. 12. O’Malley P, Brown K, Mace SE, American Academy of Pediatrics Committee on Pediatric Emergency Medicine. Patient and family centered care and the role of the emergency physician in providing care to a child in the emergency department. Pediatrics. 2006;118:2242–2244. 13. Graedon J, Graedon T. Enlisting families as patient safety allies. Clin Pediatr Emerg Med. 2006;7:265–267. 14. Patterson A, Frush DP, Donnelly LF. Helical CT of the body: are settings adjusted for pediatric patients? Am J Radiol. 2001;176:297–301.

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CHAPTER REVIEW 15. Goske MJ, Applegate KE, Boylan J, et al. The image gently campaign: working together to change practice. Am J Radiol. 2008;190:273–274. http://www.ajronline.org/cgi/content/ full/190/2/273. Accessed July 1, 2009. 16. Kupperman N, Holmes JF, Dayan PS, et al. Identification of children at very low risk of clinically important brain injuries after head trauma: a prospective cohort study. Lancet. 2009;374:1160–1170. 17. Oman JA, Cooper RJ, Holmes JF, et al. Performance of a decision rule to predict need for computed tomography among children with blunt head trauma. Pediatrics. 2006;117:e238–e246. 18. Osmond MH, Klassen TP, Wells GA, et al. CATCH: a clinical decision rule for the use of computed tomography in children with minor head injury. Can Med J Assn. 2009;182:341–348. 19. Jiminez RR, Deguzman MA, Shiran S, et al. CT versus plain radiographs for evaluation of c-spine injury in young children: so benefits outweigh risks? Pediatr Radiol. 2008:38:635–644. 20. Polk-Williams A, Carr BG, Blinman TA, et al. Cervical spine injury in young children: a National Trauma Data Bank review. J Pediatr Surg. 2008;43:1718–1721. 21. McCall T, Fassett D, Brockmeyer D. Cervical spine trauma in children: a review. Neurosurg Focus. 2006;20:E5. 22. Schuh S, Laiani A, Allen U, et al. Evaluation of the utility of radiography in acute bronchiolitis. J Pediatr. 2007;150:429–433. 23. Pate JC, Tepas JJ. The efficacy of focused abdominal sonography for trauma (FAST) as a screening tool in the assessment of injured children. J Pediatr Surg. 1999;34:44–47. 24. Sola JE, Cheung MC, Yang R, et al. Pediatric FAST and elevated liver transaminases: an effective screening tool in blunt abdominal trauma. J Surg Res. 2009;157:103–107. 25. Holmes JF, Sokoleve PE, Brant WE, et al. Identification of children with intra-abdominal injuries after blunt trauma. Ann Emerg Med. 2000;39:500–509. 26. Holmes JF, Mao A, Awasthi S, et al. Validation of a prediction rule for the identification for children with intra-abdominal injuries after blunt torso trauma. Ann Emerg Med. 2009;54:528–533. 27. Ramarajan N, Krishnamoorthi R, Barth R, et al. An interdisciplinary initiative to reduce radiation exposure: evaluation of appendicitis in a pediatric emergency department with clinical assessment supported by a staged ultrasound and computed tomography pathway. Acad Emerg Med. 2009;16:1258–1265.

28. Fefferman NR, Roche KH, Pinkney LP, et al. Suspected appendicitis in children: focused CT technique for evaluation. Radiology. 2001;220:691–695. 29. Israel GM, Malguria N, McCarthy S, et al. MRI vs ultrasound for suspected appendicitis during pregnancy. J Magn Reson Imaging. 2008;28:428–433. 30. Ambrose VL, Vos P, Tiwari P, et al. Evaluation of MRI for the diagnosis of appendicitis during pregnancy when ultrasound is inconclusive. J Surg Res. 2009;156:145–149. 31. Riccabona M. Potential of MR-imaging in the paediatric abdomen. Eur J Radiol. 2008;68:235–244. 32. Hormann M, Paya K, Eibenberger K, et al. MR imaging in children with nonperforated acute appendicitis: value of unenhanced MR imaging in sonographically selected cases. AJR Am J Roentgenol. 1998;171:467–470. 33. Cobben L, Groot I, Kingma L, Coerkamp E, Puylaert J, Blickman J. A simple MRI protocol in patients with clinically suspected appendicitis: results in 138 patients and effect on outcome of appendectomy. Eur Radiol. 2009;19:1175–1183. 34. Inci E, Hocaoglu E, Aydin S, et al. Efficiency of unenhanced MRI in the diagnosis of acute appendicitis: comparison with Alvarado scoring system and histopathological results. Eur J Radiol. 2010 Jul 21 [Epub ahead of print]. 35. Hryhorczuk AL, Strouse PJ. Validation of US as a firstline diagnostic test for assessment of pediatric ileocolic intussusception. Pediatr Radiol. 2009;39:1075–1079. 36. Vieira RL, Levy JA. Bedside ultrasonography to identify hip effusions in pediatric patients. Ann Emerg Med. 2009;55:284–289. 37. Shavit I, Eidelman M, Galbraith R. Sonography of the hip joint by the emergency physician: its role in the evaluation of children presenting with acute limp. Pediatr Emerg Care. 2006;22:570–573. 38. Ramirez-Schrempp D, Dorfman DH, Baker WE, et al. Ultrasound soft-tissue application in the pediatric emergency department: to drain or not to drain? Pediatr Emerg Care. 2009;25:44–48.



Chapter Review Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

24-13

CASE SUMMARY

1

CHAPTER REVIEW

A 3-year-old girl presents to the emergency department (ED) with a history of head trauma 3 hours ago, when she fell from a stool and struck her occiput on a hard floor. There was no loss of consciousness, but she vomited twice. Her parents have noted a large, tender swelling over her occiput. She is subdued and cooperative but not drowsy. She has experienced headaches for the past 8 days. She has a headache now, but it not severe. She has been treated with acetaminophen (paracetamol) and ibuprofen, which seem to help her headaches. Vital signs on examination are as follows: temperature, 37.0°C (98.6°F); pulse, 85/min; respirations, 30/min; and blood pressure, 80/55 mm Hg. She is of average size and build. She is quiet and cooperative. Her parents point out that she is normally more active than this. Her head shows some tenderness over her occiput with moderate swelling and bruising. No deformity is palpable. Eyes show equal and reactive pupils. Extraocular movements are full. She is cooperative, and a funduscopic examination reveals sharp optic disc margins and no retinal hemorrhages. Tympanic membranes are normal. No bruising is evident elsewhere. Her nose is clear. Her mouth examination results are normal. Her neck is nontender and supple, with a full range of motion. The results of heart, lung, abdomen, and back examinations are normal. She ambulates normally. Her reflexes are normal. She has some risk of serious brain injury, but her risk appears to be low. Taking an antiplatelet agent such as ibuprofen before the head trauma episode might increase her risk of intracranial hemorrhage. With her prior history of headaches, there are other diagnostic possibilities of concern. 1. 2. 3. 4.

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Should a brain imaging study be performed in the ED? Should brain imaging include CT and MRI as options? What should the parents be told during the consent process for CT and/or MRI? Are these options and decisions likely to change over time (ie, this year vs 5 years from now)?

Imaging Decision-Making Strategies and Considerations Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

CASE SUMMARY

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A brain imaging study should be strongly considered for this patient; however, this has some risk of adverse effects, which should be reviewed with her parents. Although CT is fast, it exposes her brain to radiation. Magnetic resonance imaging has no high energy radiation risk; however, it is slow and it will require intravenous sedation. There is also the option of not performing any imaging study; however, if there is an intracranial condition, this could delay necessary treatment. If we apply the decision rule published by Kupperman et al,16 this child has up to three of the six factors that exclude her from the low-risk group. Although she does not have a severe mechanism, signs of basilar fracture, or loss of consciousness, her parents state that her mental status is not normal even if she has a Glasgow Coma Scale score of 15. She also has a history of emesis and a headache that is complicated by the fact that she has had it for the past 8 days. A brain imaging study is indicated. In most hospitals the current practice would be to perform CT because it is widely available and gives a rapid answer. The risk and feasibility of sedating the child (including the fasting time) for an MRI should be considered. Currently, MRI is not available at all times at most children’s hospitals, and transferring to a children’s hospital could delay care and treatment for acute injury. If it is close by, transferring to a children’s hospital can have advantages because most use a lower CT radiation dose than adult facilities. If the major concern is not for an acute injury but to rule out brain disease, such as tumor, because the child has had a headache for the past 8 days and is well appearing with normal examination results, then an MRI is preferred, but this can be performed as an outpatient or in the ED, depending on the timing and availability of resources. In the future, MRI should be more widely available, and most children’s hospitals should be able to perform MRI at all times in the ED. As technology advances and MRI of the brain becomes more rapid, there should be better access, staffing, and feasibility in performing MRI, which would be ideal for this patient, who has experienced an acute injury and has a less acute problem that is suggestive of a brain tumor.

Photo Credits Opener © Matthew Staver/Landov Unless otherwise indicated, all photographs and illustrations are under copyright of Jones & Bartlett Learning, courtesy of Maryland Institute for Emergency Medical Services Systems, or the American Academy of Pediatrics. Some images in this book feature models. These models do not necessarily endorse, represent, or participate in the activities represented in the images.



Chapter Review Copyright © 2012 by the American Academy of Pediatrics and the American College of Emergency Physicians

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