White Paper | Carestream products address challenges in pediatric imagingMaximizing Dose Efficiency for PediatricPatient I...
White Paper | Carestream products address challenges in pediatric imaging2opportunities to develop task-specific tailoring...
White Paper | Carestream products address challenges in pediatric imaging3Once an image has been acquired, the rapid displ...
White Paper | Carestream products address challenges in pediatric imaging4Figure 4. A teenage chest image processed with b...
White Paper | Carestream products address challenges in pediatric imagingwww.carestream.comCarestream Health, Inc., 2012. ...
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Maximizing Dose Efficiency for Pediatric Patient Imaging

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The following white paper explains the principles in general X-Ray procedures that should be followed throughout the three stages of the imaging process (Image acquisition, image processing for display, and image review and assessment) in an effort to provide safe imaging practices to pediatric patients.

For more information on Carestream's pediatric solutions, visit http://carestream.com/pediatrics

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Maximizing Dose Efficiency for Pediatric Patient Imaging

  1. 1. White Paper | Carestream products address challenges in pediatric imagingMaximizing Dose Efficiency for PediatricPatient ImagingIntroductionRadiographic imaging of pediatric patients presents a numberof unique challenges compared to the imaging of adults. Theincreased radiation sensitivity of growing organs and bones,children’s longer expected life spans and the large range ofbody habitus encompassed by this patient demographic allmean that it’s not appropriate to use the same acquisitiontechniques and image-processing parameters used for adultimaging. The Image Gently campaign’s “Back to Basics”initiative encourages the use of pediatric-specific imagingpractices and is completely consistent with the guidingprinciples in Carestream’s approach to addressing theseimportant issues.1 2 3To provide the highest quality image with the most efficientuse of the radiation exposure, it’s important to address eachstep in the image-formation chain as part of a completesystem. The image-formation process can be naturally dividedinto three distinct stages: image acquisition, image processingfor display, and image review and assessment. These steps arerepresented in Figure 1. The process of image-qualityassessment and its essential role in driving positive feedbackinto the acquisition and image processing steps are alsoindicated in this figure.Figure 1. Flow diagram for the image-formation process.Image review and assessment allow for feedback into theacquisition and image-processing steps, which can drivecontinued improvement.In keeping with the spirit of the Image Gently initiative,Carestream Heath has developed and implemented a numberof product features specifically aimed at ensuring optimalimage acquisition and display of diagnostic information acrossthe full range of pediatric patients. The following sectionsoutline some of these capabilities.Image AcquisitionThe first stage of image formation is the capture of the X-rayimage by the image receptor. The recent introduction ofCarestreams innovative, untethered, wireless DRX detectorproducts has been a major step forward in the provision of ahigh-quality X-ray detector that fits seamlessly into theworkflow of the NICU and pediatric ICU. In addition, the useof a CsI(Tl) X-ray absorption layer helps to ensure the highestpossible image quality. The untethered design virtuallyeliminates the problems that can be encountered with patientpositioning in a busy clinical environment when a tetheredsystem is used. The replaceable battery also guarantees thatthe detector is ready for use at a moment’s notice.In addition to a highly efficient detector, it’s also essential touse the appropriate acquisition protocols (e.g. kVp, mAs andfiltration) across the wide range of pediatric body habitus. Thewide range of body sizes – from the smallest neonatal patientto the largest adolescent – requires acquisition techniques tobe tailored to each patient’s size and age. To help with thischallenge, Carestream offers the ability to select the pediatricpatient body size from a range of seven categories, based onthe recent FDA recommendations.4 5This newly categorizedselection allows the system to choose default acquisitionparameters and image-processing configurations appropriatefor the different types of patients as well as the differentdetector types (Pediatric Capture Image Optimization &Enhancement Software). This capability provides a moreconsistent acquisition and display of images for patients withina given body size and age range.Carestream is also engaged in research to develop improvedacquisition techniques for pediatric patients. This work is basedon the realization that the use of a digital receptor opens thepossibility for targeting a specific signal-to-noise ratio in theimage, versus maintaining a specific optical density within thefinal image. The inherent separation of the acquisition anddisplay of an image in the digital environment provides newAcquisition ImageProcessingReview andAssessmentAcceptImage
  2. 2. White Paper | Carestream products address challenges in pediatric imaging2opportunities to develop task-specific tailoring for the amountand type of radiation used to create digital images.To illustrate the opportunity for technique optimization,Figure 2 shows a normalized image-quality metric (detectabilityindex per unit of effective absorbed dose) for a 5-10mm sizedlung nodule, as a function of patient weight. The resultsindicate that for smaller patients, a lower kVp can provideimproved image quality for a given patient dose, while higherkVps are more beneficial for larger patients. (The results arenormalized to those for the 70kVp technique.)Figure 2. Normalized image quality (nodule detectability index) per unit absorbed effective dose for different kVps as a function ofpatient weight for a 5-10mm lung nodule. The data is normalized to the image quality result for the 70kVp case.In certain procedures, such as scoliosis exams, it may bepossible to reduce the exposure levels used for the follow-upimages. Exposure reduction works if the imaging task can besatisfactorily achieved with an image that is noisier than thehigh-quality primary exam but still provides sufficientdelineation of the spinal processes to allow accurate clinicalevaluation. In this specific example, in addition toinvestigating dose-reduction strategies, Carestream Healthhas also implemented a long-length imaging capability thatminimizes the amount of overlap between consecutiveimages. This reduces patient exposure and ensures maximalcoverage of the anatomical field of view.
  3. 3. White Paper | Carestream products address challenges in pediatric imaging3Once an image has been acquired, the rapid display of thepreview image allows the radiographer to quickly decidewhether the patient’s anatomy was correctly captured or ifthe image needs to be retaken. This improves the speed andefficiency involved in completing exams, which is particularlyimportant for young patients. To help, Carestream hasimplemented the new IEC Exposure Index (EI) standard forquick assessment of the amount of radiation used to createthe image.6 7The associated Deviation Index (DI) allows animmediate evaluation of the acquisition technique comparedto the institutional target of exposure for the given exam.This immediate feedback, coupled with the otherdevelopments in technique selection described above, helpsthe radiographer provide more consistent image quality fromthe detector to the next step in the imaging chain, the imageprocessing.Image Processing and DisplayOnce a high-quality image has been acquired at the lowestpossible patient exposure, it’s essential to performappropriate image processing that presents the diagnosticinformation clearly and most efficiently to the radiologist.Carestreams EVP Plus Software can be tailored to adjust theimage-processing parameters to an individual site’spreference. With information about the patient’s size andage, the IP parameters can also be adapted to display thefeatures of the clinical information in a more informativeway compared to using adult image-processingconfigurations. The eight-band frequency decomposition,multi-frequency noise reduction and controlled edge-restoration capabilities mean that the available clinicalcontent of the bony structures in the smallest NICU patientscan be appreciated as well as the trabecular detail of oldermore developed patients, as one example. The fine detailand lower contrast of the smallest NICU patient’s anatomyrequires accentuation of different frequency componentsthan the features of the larger adolescents. Figures 3 and 4illustrate these differences and show the improvedvisualization provided by careful selection of the appropriateimage-processing parameters.Figure 3. An infant chest image processed with both adult (left) and infant (right) image processing. Note that many infant chestdetails are not apparent when using adult processing.
  4. 4. White Paper | Carestream products address challenges in pediatric imaging4Figure 4. A teenage chest image processed with both adult (left) and infant (right) image processing. Note that fine details of theteen chest are overemphasized when using infant processing.Quality Acceptance and ControlOnce an imaging system has been installed and tailored to asite’s preferences for patient exposure and image "look,” it’simportant to have an ongoing quality control (QC) program inplace that ensures the continued high quality of the imagesdelivered to the reading radiologist. There are multiple aspectsto this type of QC program and Carestream Health hasimplemented a number of system capabilities that enable a siteto easily track many of the important parameters.At the front end, the DR Total Quality Tool (DR TQT) packageallows for efficient evaluation of the digital X-ray detector’scurrent performance level. In addition, the IEC EI allows quickevaluation of the exposure levels used to acquire the images.On a departmental level, the Administrative Reporting andAnalysis Software allows the QC technician or physicist toquery all the Carestream systems across the institutionalnetwork from a single, central location. This can quicklyhighlight anomalous exposure levels, high repeat rates or otherimage-quality issues that can develop, and allows for moreproactive steps to solve potential problems. Together, thesesystem capabilities can help technologists maintain their highlevel of image quality and consistency.ConclusionThe unique demands of pediatric imaging require a system-wide approach to guarantee high-quality imaging at thelowest possible patient exposure. Carestream Health offers arange of features and functionality that ensure our systems canprovide the best and safest possible X-ray imaging across thefull clinical range of exams for all pediatric patients.
  5. 5. White Paper | Carestream products address challenges in pediatric imagingwww.carestream.comCarestream Health, Inc., 2012. CARESTREAM is a trademark ofCarestream Health. CAT 200 0013 10/121Bulas DI, et al. AJR Am J Roentgenol. 2009 May;192(5):1176-8. Image Gently: Why We Should Talk to Parents about CT in Children.2AJR Am J Roentgenol. 2009 May;192(5):1169-75. Image Gently Vendor Summit: Working Together for Better Estimates of Pediatric RadiationDose from CT. Strauss KJ, et al.3Image Gently®: The Alliance for Radiation Safety in Pediatric Imaging. http://www.pedrad.org/associations/5364/ig/ (Accessed September 27th2012)4FDA guidance entitled “Premarket Assessment of Pediatric Medical Devices,” May 14, 2004,http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM089742.pdf5FDA draft guidance entitled “Draft Guidance for Industry and Food and Drug Administration Staff: Pediatric Information for X-ray ImagingDevice Premarket Notifications,” May 10, 2012,http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM302938.pdf6International Standard IEC 62494-1 (2008) Medical electrical equipment—exposure index of digital X-ray imaging systems—Part 1: definitionsand requirements for general radiography. International Electrotechnical Commission, ISBN 2-8318-9944-37Seibert J.A., Morin R.L., “The standardized exposure index for digital radiography; an opportunity for optimization of radiation dose to thepediatric population”, Pediatric. Radiol. 41(5), (2011), 573-581

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