With potential to deliver a higher radiation dose compared to all other modalities, it is especially important to consider the correct exam is being ordered for the indication. American College of Radiology has compiled a list of recommended studies per indication to aid the referring physician.

https://acsearch.acr.org/list

CT remains standard of care for a number of indications, even in the pediatric patient, despite radiation exposure associated with this modality.  For example, trauma of any sort where the patient is unstable and time is of essence, as well as various head trauma situations, staging of a number of tumors, evaluation for pulmonary embolus and more.

Motion, however with faster scan acquisition and motion correction post-processing, this is improving.

Metal resulting in streak artifact degrading detail (also improving with newer software).

True estimation of dose once study is performed still remains challenging.

Frush, D.P. Pediatr Radiol (2011) 41(Suppl 2): 483. doi:10.1007/s00247-011-2098-z

CT uses radiation to acquire images. It is generally accepted that there is some small increased risk of cancer associated with radiation exposure.  Therefore, the use of alternate modalities, such as ultrasound or MRI, that do NOT use radiation to acquire images is recommended when feasible to decrease the overall number of CTs performed. When CT is the imaging modality indicated, the goal is to optimize the CT protocol to the lowest possible dose and still have a diagnostic study.

Callahan, M.J. Pediatr Radiol (2011) 41(Suppl 2): 488. doi:10.1007/s00247-011-2099-y

It is the responsibility of the radiologist and the ordering physician to facilitate a collegial environment, assuring the correct exam is ordered to answer the question posed. It is also the responsibility of manufacturer, radiologist, technologist and physicist to diligently tailor and revise protocols to decrease radiation dose.

http://www.imagegently.org/Procedures/Computed-Tomography

http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/CT_Pediatric.pdf

Think-A-Head and Image Gently campaign

http://www.imagegently.org/Procedures/Minor-CT-in-Head-Injuries

Head CT protocols

http://www.imagegently.org/Portals/6/Procedures/IG%20CT%20Protocols%20111714.pdf

ALARA (as low as reasonably achievable) CT 2011 executive summary

Newman, B. & Callahan, M.J. Pediatr Radiol (2011) 41(Suppl 2): 453. doi:10.1007/s00247-011-2154-8

https://www.aapm.org/pubs/CTProtocols/documents/PediatricRoutineHeadCT.pdf

Accreditation for CT is available through the American College of Radiology (ACR).

http://www.acraccreditation.org/Modalities/CT

https://www.acr.org/Quality-Safety/National-Radiology-Data-Registry/Dose-Index-Registry

Justification and optimization of CT in children: how are we performing?

“It has been 10 years since the original pediatric CT ALARA conference in 2001, so it is fitting that we look back at our progress. The following material will look at how we might quantify our performance regarding the justification and optimization of radiation protection. It will also summarize some of the efforts and initiatives that have likely contributed to these changes.”

Frush, D.P. Pediatr Radiol (2011) 41(Suppl 2): 467. doi:10.1007/s00247-011-2097-0

MRI is used for numerous reasons during work up of symptoms in the neonatal period.

Advantages over CT include no ionizing radiation, improved sensitivity for evaluation of infarction and white matter changes and advanced imaging techniques that may help with prognostication (MR spectroscopy and diffusion tensor imaging (DTI).

-More common indications include neonatal encephalopathy, acquired brain injury, etiology of neonatal seizures, hypoxic ischemic encephalopathy (HIE), congenital malformations,  focal cerebral injury including arterial and venous stroke, intracranial hemorrhage, toxic and metabolic disorders, bilirubin encephalopathy, birth trauma and evaluation of neonatal meningitis.

- May have a role in pre and post-operative evaluation of brain in neonates with congenital heart diseases (CHD), particularly high risk infants with CHD.

Jansen, F. A. R. et al, (2016) Fetal brain imaging in isolated congenital heart defects – a systematic review and meta-analysis. Prenat Diagn, 36: 601–613. doi: 10.1002/pd.4842.

Khalil A et al. Brain abnormalities and neurodevelopmental delay in congenital heart disease: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2014;43:14-24.

- May have a role in determining brain insult following decannulation of extra corporeal membrane oxygenation (ECMO) in patients with neurological signs.

Rollins MD et al. Utility of neuroradiographic imaging in predicting outcomes after neonatal extracorporeal membrane oxygenation. J Pediatr Surg. 2012;47:76-80.

- May have a role in predicting neurodevelopmental outcomes in preterm neonates when performed at term equivalent age.

Kwon, SH et al, Role of Neuroimaging in Predicting Neurodevelopmental Outcomes of Preterm Neonates. DOI: http://dx.doi.org/10.1016/j.clp.2013.10.003

Thayyil S. et al., Cerebral magnetic resonance biomarkers for predicting neurodevelopmental outcome following neonatal encephalopathy: a meta-analysis. Pediatrics. 2010;125(2). Available at: www.pediatrics.org/cgi/ content/full/125/2/e382.  And Hintz SR, Barnes PD, Bulas D, et al. Neuroimaging and Neurodevelopmental Outcome in Extremely Preterm Infants. Pediatrics. 2015;135(1):e32-e42. doi:10.1542/peds.2014-0898.

- Role in prognosis in HIE, particularly with MR spectroscopy, ideally performed between 5-14 day of life.

Barkovich AJ et al, MR imaging, MR spectroscopy, and diffusion tensor imaging of sequential studies in neonates with encephalopathy. Am J Neuroradiol. 2006;27:533- 47

- Anatomical detail of spine malformations

-Hemangiomas and vascular malformations, helpful for lesion characterization and anatomic extent of lesion.

-Congenital cystic masses of the head and neck region.

-Mediastinal vascular anomalies – rings and slings. MRI is useful for demonstrating vascular anatomy and relationship to airway without the use of intravenous contrast, as well as for creation of 3D reconstructions.

-Anatomic delineation of congenital pelvic GI/GU anomalies, role for MRI for anatomic clarification in some cases.

-Neoplastic and other masses of the neonatal period

Motion limitations and length of study.

Feasibility of patient transport to MRI scanner, particularly in a fragile neonate.

Monitoring NICU patient in the scanner and MR environment with MR safe equipment.

Optimization of neonatal MRI parameters particularly in machines with older software.

Vacuum immobilizer and feed and bundle

Haney, B. et al, Magnetic Resonance Imaging Studies Without Sedation in the Neonatal Intensive Care Unit Safe and Efficient. J Perinat Neonat Nurs Vol. 24, No. 3, pp. 256–266.

Safety Guidelines for Magnetic Resonance Imaging Equipment in Clinical Use
http://www.ismrm.org/smrt/files/con2033065.pdf

ACR Guidance on MR Safe Practices: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jmri.24011/pdf

Anesthesia research in pediatrics http://smarttots.org/

To avoid sedation or general anesthesia, several sites do “feed and wrap/feed and bundle” technique in infants typically less than 3 months with swaddling and optional pacifier with or without oral sucrose solution.  Sedation may be necessary if these methods fail. There are several standards of care mandates from AAP, ASA, JAHCO pertaining to neonatal sedation, as well as new research about potential dangers of infant sedation.
Harrison D et al, Efficacy of sweet solutions for analgesia in infants between 1 and 12 months of age: a systematic review. Archives of Disease in Childhood 2010; 95(6): 406-413.

Vitals and thermoregulation:  Physiological monitoring, including oxygen saturation, blood pressure, end tidal carbon dioxide and heart rate, is suggested. Temperature control especially in preterm infants is important. Infants are prone to hypothermia in the scanner environment. This in turn can lead to heat loss and depletion of fragile metabolic infant reserve.
Battin, M. et al, Physiological stability of preterm infants during magnetic resonance imaging, Early Human Development, Volume 52, Issue 2, 1 September 1998, Pages 101-110, ISSN 0378-3782, http://dx.doi.org/10.1016/S0378-3782(98)00024-3.
Plaisier A et al. Safety of routine early MRI in preterm infants. Pediatric Radiology. 2012;42(10):1205-1211. http://dx.doi:10.1007/s00247-012-2426-y

MR safe monitoring and anesthetic equipment and MR compatible transport equipment are a must.  Personnel must pay close attention to endotracheal tubes, ventilation machines, artifacts from small portions of metals in intravenous and central venous catheters and also make distinction between MR safe (no ferromagnetic material, but may malfunction in the magnetic field) vs. MR compatible (unaffected by the magnetic field) equipment. ECG leads, pulse oximeter, ventilation equipment (with extra-long tubing if required), and infusion pumps should be MR compatible. 
Mathur, A.M. et al, Transport, monitoring, and successful brain MR imaging in unsedated neonates. Pediatr Radiol (2008) 38: 260. http://dx.doi:10.1007/s00247-007-0705-9 

MR compatible incubator are available with or without built in neonatal RF coils to provide superior image quality, as well as to ensure better physiological stability. Vacuum immobilizer device can be used to decrease motion artifact and potentially eliminate risk of sedation.
Paley M. et al, An MR-compatible neonatal incubator. The British Journal of Radiology. 2012;85(1015):952-958. http://dx.doi:10.1259/bjr/30017508 
Haney, B. et al, Magnetic Resonance Imaging Studies Without Sedation in the Neonatal Intensive Care Unit Safe and Efficient. J Perinat Neonat Nurs Vol. 24, No. 3, pp. 256–266.

Dedicated neonatal intensive care unit MRI units are being developed in a few centers around the world.  A small footprint MRI developed in Cincinnati Children’s hospital is being used clinically and has various advantages. Tkach, J. et al, MRI in the Neonatal ICU: Initial Experience Using a Small-Footprint 1.5-T System. American Journal of Roentgenology 2014 202:1, W95-W105

Gadolinium in newborn: Gadobutrol (Gadavist®) approved for use in magnetic resonance imaging “to detect and visualize areas with disrupted blood brain barrier (BBB) and/or abnormal vascularity of the central nervous system in pediatric patients less than 2 years of age (including term neonates).” https://www.radiologysolutions.bayer.com/products/mr/contrast/gadavist/
Other uses are off label in neonates. Neonates have immature renal function and remain at higher theoretical risk for nephrogenic systemic fibrosis.
http://www.acr.org/Quality-Safety/Resources/Contrast-Manual - ACR Manual on Contrast Media
Gadolinium deposition is known to occur. However, to date, no signs or symptoms of adverse health effects and no pathological changes have been associated with these gadolinium deposits in the brain. FDA investigating risk of brain deposits following repeated GBCA (Gadolinium based MR contrast agents).
http://www.fda.gov/Drugs/DrugSafety/ucm455386.htm

Biomedical implant hazards: as with all MRI evaluations, MR compatibility of implanted medical devices should be checked. Manufacturer guidelines must be followed if device is MR conditional.
Biomedical implant hazards, Institute for Magnetic Resonance Safety, Education and Research
http://www.mrisafety.com

This a potential noise hazard with MRI. Prolonged exposure to noise levels above 85 decibels can lead to hearing loss with much shorter durations of exposure required at higher decibels. Use of earplugs, headphones and/or earmuffs is being universal. Several MR vendors now offer noise reduction technology.
McJury PhD, M. and Shellock PhD, F. G. (2000), Auditory Noise Associated With MR Procedures: A Review. J. Magn. Reson. Imaging, 12: 37–45. doi:10.1002/1522-2586(200007)12:1<37::AID-JMRI5>3.0.CO;2-I..

Gradient magnetic field effects can induce currents in conductive tissues of the body, which in theory can lead to peripheral nerve stimulation or even cardiac stimulation although these are not observed during routine clinical MRI.

Radiofrequency (RF) pulse related power deposition and tissue heating, especially in patients with poor thermoregulatory control can occur. Specific absorption rate is the rate at which RF field deposits energy. Local temperature fluctuations are difficult to predict. SAR limits 3.2 W/kg over 10 minutes for head and 4 W/kg for body. Additional attention must be given to ensure MR compatibility of monitoring equipment, which may heat and cause skin burns such as pulse oximetry monitors and EKG leads. http://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm072688.pdf

Emergencies in MR suite may arise and proper protocol for emergent evacuation of sick infant from the scanner room for resuscitation should be in place. Policies to guide safe handling of patient and personnel in the event of a quench during an MR examination should also be in place.

Safety of any accompanying family member or medical personnel, including hearing protection and screening for implantable devices, is mandatory.

MRI of the neonatal brain by Mary A Rutherford

http://www.mrineonatalbrain.com/

British Association of Perinatal Medicine: Fetal and Neonatal Brain Magnetic Resonance Imaging: Clinical Indications, Acquisitions and Reporting, A Framework for Practice

http://www.bapm.org/publications/documents/guidelines/BAPM%20MRI%20standards%20for%20fetal%20neonatal%20brain%20imaging_FINAL%20SUBMISSION%20080216.pdf

Safety Guidelines for Magnetic Resonance Imaging Equipment in Clinical Use

http://www.ismrm.org/smrt/files/con2033065.pdf

Biomedical implant hazards, Institute for Magnetic Resonance Safety, Education and Research

http://www.mrisafety.com/

HIE work up recommendations for HIE

http://emedicine.medscape.com/article/973501-workup#c5

Practice Parameters ACR

https://www.acr.org/~/media/ACR/Documents/PGTS/standards/MonitorMRIEquipment.pdf

https://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/Skeletal_Surveys.pdf

Tocchio, S. et al, MRI evaluation and safety in the developing brain, Seminars in Perinatology, Volume 39, Issue 2, March 2015, Pages 73-104, ISSN 0146-0005. http://dx.doi.org/10.1053/j.semperi.2015.01.002.

Arthurs, O.J. et al, Challenges of neonatal MRI, Pediatr Radiol (2012) 42: 1183. doi:10.1007/s00247-012-2430-2  

Updated Classification of Pediatric Vascular Anomalies/Terminology

Kollipara R, Dinneen L, Rentas KE, et al. Current Classification and Terminology of Pediatric Vascular Anomalies. AJR 2013; 201:1124–1135. DOI:10.2214/AJR.12.10517

Guidelines for Staging of Neuroblastic Tumors

Brisse HJ, McCarville MB, Granata C, et al. Guidelines for Imaging and Staging of Neuroblastic Tumors: Consensus Report from the International Neuroblastoma Risk Group Project. Radiology 2011; 261:243-257. DOI: 10.1148/radiol.11101352

Ultrasound should be the first line imaging modality for many indications in the infant. For example, pyloric stenosis, sacral dimple, hip dysplasia until proximal femoral epiphyses are ossified (approximately 4 months postnatal age), soft tissue lesions, head ultrasound for germinal matrix hemorrhage and macrocrania, fluid collections, evaluation of intraabdominal pathology and urinary tract pathology.

Ultrasound is tolerable by most patients in various circumstances. It can help answer many questions and should be readily available and utilized for broad indications in pediatrics as first line study.

•Small field of view

•Operator dependence

•Ultrasound does not perform well for bone evaluation, however some institutions still utilize ultrasound as an adjunct for fracture evaluation. 

•UGI remains the gold standard for evaluation of malrotation. 

Safety profile of ultrasound is extremely favorable. In fact, ultrasound is the preferred modality in children due to lack of ionizing radiation. The AIUM states” Diagnostic ultrasound has been in use since the late 1950s. Given its known benefits and recognized efficacy for medical diagnosis, including use during human pregnancy, the American Institute of Ultrasound in Medicine herein addresses the clinical safety of such use: No independently confirmed adverse effects caused by exposure from present diagnostic ultrasound instruments have been reported in human patients in the absence of contrast agents. Biological effects (such as localized pulmonary bleeding) have been reported in mammalian systems at diagnostically relevant exposures but the clinical significance of such effects is not yet known. Ultrasound should be used by qualified health professionals to provide medical benefit to the patient. Ultrasound exposures during examinations should be as low as reasonably achievable (ALARA).”

http://www.aium.org/officialStatements/34

There is a small risk of cell damage due to heating in certain settings, this would require prolonged duration of scanning.

http://www.aium.org/officialStatements/17

https://www.bmus.org/static/uploads/resources/BMUS-Safety-Guidelines-2009-revision-FINAL-Nov-2009.pdf

Use of ultrasound by licensed technologists and physicians with manufacturer and physicist oversight in the medical setting assures the patient of the safest and most reasonable study for diagnostic purposes. It is the responsibility of all involved; manufacturer, technologists and radiologists, to optimize parameters and techniques to minimize any potential risk, particularly in neonatal population. 

As with any imaging, ALARA principle is applied, as low as reasonably achievable.

http://www.aium.org/officialStatements/39

American Institute of Ultrasound in Medicine (AIUM)

http://www.aium.org/

AIUM includes practice parameters, guidelines for performance and documentation of images per study (includes hip, spine, head).

http://www.aium.org/resources/guidelines.aspx

American College of Radiology (ACR)

http://www.acr.org/Quality-Safety/Standards-Guidelines/Practice-Guidelines-by-Modality/Ultrasound

Hip dysplasia

http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/US_Hip_Dysplasia.pdf

Spine

http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/US_Neonatal_Spine.pdf

Head

http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/US_Neurosonography.pdf

ACR Appropriateness Guidelines- Suspected appendicitis

https://acsearch.acr.org/docs/69357/Narrative/

ACR Appropriateness Guidelines-Urinary Tract Infection Child

https://acsearch.acr.org/docs/69444/Narrative/

http://www.imagegently.org/Procedures/Ultrasound

With radiation dose to consider, it is especially important to order the correct exam for the indication. American College of Radiology has a long list of recommended studies per indication to aid the referring physician.

https://acsearch.acr.org/list

Radiographs (or x-ray) are typically not obtained for the healthy, full-term infant. They are used in the newborn setting in patients with a variety of conditions, including prematurity, abdominal complaints, vomiting, congenital heart disease, respiratory distress, lung lesions (congenital pulmonary adenomatoid malformation, bronchial atresia, congenital lobar emphysema), trauma work-up, including nonaccidental trauma, skeletal dysplasias and hospitalized infants, especially in the neonatal intensive care unit to monitor respiratory status and confirm placement of the supporting devices, such as an endotracheal tube in patients who require ventilator support. 

•Radiation

•Positioning (ability to cooperate, condition of patient, or lines inhibit)

•Small size of patients

Radiation dose considerations

https://www.acr.org/~/media/ACR/Documents/AppCriteria/RadiationDoseAssessmentIntro.pdf?la=en

ALARA

http://www.imagegently.org/Procedures/Digital-Radiography

ACR-SPR practice parameter for general radiography

https://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/General_Radiography.pdf

American College Radiology practice parameters

https://www.acr.org/Quality-Safety/Standards-Guidelines/Practice-Guidelines-by-Modality/Pediatric

With radiation dose to consider, it is especially important to order the correct exam for the indication. American College of Radiology has a long list of recommended studies per indication to aid the referring physician.

https://acsearch.acr.org/list

Enema under fluoroscopy: to investigate potential causes of lower intestinal obstruction such as Hirschsprung disease, meconium ileus, small left colon syndrome, ileal atresia, colonic atresia, and congenital anomalies such anorectal malformation.   It is diagnostic and therapeutic for ileocolic intussusception and is useful for post-operative evaluation of the colon.

Upper GI and small bowel examination: to investigate potential causes of abdominal pain, vomiting, diarrhea, upper intestinal obstruction, and failure to thrive. It is useful in diagnosis congenital syndromes or anomalies associated with intestinal malrotation and midgut volvulus, gastric outlet obstruction, duodenal laceration/hematoma, and postoperative anatomy evaluation.

http://www.acr.org/~/media/4F40CBF4796A4A9AB74530F503400CBA.pdf

Esophagram: To investigate potential causes of stridor, dysphagia, odynophagia, unexplained pneumomediastinum, recurrent pneumonia or chronic tracheobronchial inflammation. It is useful in diagnosis and evaluation of tracheoesophageal fistula, great vessel anomalies, foreign bodies, stricture, and esophageal obstruction.

https://www.acr.org/~/media/A77716DEDE5C486EA73F2249D578FD39.pdf

Voiding cystourethrography: to investigate potential causes of urinary tract infection, hematuria, hydronephrosis, hydroureter, and bladder outlet obstruction. To evaluate for congenital anomalies of the urinary tract and postoperative evaluation of the urinary tract. http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/Voiding.pdf

•Radiation exposure

•Limited by motion

http://www.imagegently.org/Procedures/Fluoroscopy

Rama S. Ayyala, MD, Chair
Emily M. Janitz, DO, Vice Chair
Karen Blumberg, MD, FACR
Judy A. Estroff, MD
Tara L. Holm, MD
Shailee V. Lala, MD
Brooke S. Lampl, DO
David W. McDonald, MD
Richard Parad, MD
Pallavi Sagar, MD
Cassandra M. Sams, MD
Mitchell L. Simon, MD
Jennifer L. Williams, MD