Lessening radiation risk for children with congenital and acquired heart disease

Newly released recommendations for pediatric radiation safety will be discussed during the Society for Cardiovascular Angiography and Interventions (SCAI) 2017 Scientific Sessions in New Orleans. Theposition paper, “Radiation Safety in Children with Congenital and Acquired Heart Disease: A Scientific Position Statement on Multimodality Dose Optimization from the Image Gently Alliance,” provides cardiologists,radiologists, pediatricians and internal medicine physicians guidance for treating pediatric patients withcongenital and acquired heart disease (CAHD). Leading experts will discuss these recommendations during the Image Gently Campaign: Radiation Safety in Pediatric Catheterization session, Wednesday, May 10.

Congenital heart disease is the most common birth defect, affecting an estimated one million children living inthe U.S. Forms of acquired heart disease affect an additional one out of every 100,000 children and adolescents annually. Children with CAHD often have complex diseases and many require life-long medical care. As part of their care, they often require cardiac imaging procedures that use ionizing . While these imaging procedures, including fluoroscopically guided procedures such as cardiac catheterization, computed tomography scans, and nuclear medicine studies, are critical for accurate diagnosis and intervention, ionizing radiation in high doses can be harmful. There is general recognition that procedural ionizing radiation doses should be kept as low as reasonably achievable.

“There is a need for consensus recommendations for ionizing radiation dose optimization and a regulation ofdose metrics across imaging procedures,” said lead author Kevin D. Hill, MD, Division of Pediatric Cardiology,Duke University Medical Center. “Our goal is to focus on approaches that, when properly implemented, willlessen radiation risks for children with while still allowing the imaging procedures to be effective.”

Recommendations include strategies for during:

  • Cardiac computed tomography procedures, including approaches that can be implemented during patient preparation, as well as scanner-based approaches.
  • Nuclear cardiology procedures, including procedural approaches and guidelines for determining administered activity in children.
  • Fluoroscopically guided procedures including and electrophysiology procedures,including recommendations focused on hardware features, software configuration and operator dependenttechniques.

Other strategies to improve care include a patient-centered approach to imaging, emphasizing education andinformed decision making, and programmatic approaches to ensure appropriate dose monitoring.

https://medicalxpress.com/news/2017-05-lessening-children-congenital-heart-disease.html |May 9, 2017

Optimizing Medical Imaging for Children of All Sizes

A proposed framework balances quality and safety of computed tomography protocols across a range of body sizes in pediatric populations.

Pediatric patients come in many sizes, from newborns to teenagers, and the wide range poses an ongoing challenge for medical imaging. In a study published in August in the Journal of Medical Imaging, researchers set out to formulate a systematic, evidence-based method to minimize radiation dose while maximizing the diagnostic performance of computed tomography (CT) imaging for young patients. According to the authors, their model could be used to optimize individual scan parameters and provide for consistent diagnostic performance across the broad range of body sizes in children.

“This study provides a framework by which one can determine the exact technique and the amount of radiation dose that is appropriate as a function of patient size and age, such that the diagnostic quality from the images is ensured,” said first author Ehsan Samei, a professor of radiology at Duke University School of Medicine in North Carolina. “This is important, as it provides a scientific basis for proper CT imaging of children, ensuring the safety and quality of the examination.”

For the most part, past efforts to develop size-specific CT protocols for pediatric populations have relied on radiation dose alone. Ideally, these protocols should also take into account diagnostic accuracy and the trade-offs between these two factors for different pediatric patient sizes. “The imaging technique needs to be adjusted according to the patient size and age, but up to now, there has been little evidence on how this adjustment should take place,” Samei said.

To address this issue, Samei and his collaborators developed a framework for balancing quality and safety for varying pediatric patient sizes. The researchers devised their methodology based on data from their two prior studies on 30 pediatric patients who had undergone clinical chest CT imaging. In one of these studies, they determined doses as a function of patient size and scan parameters. In the other study, they characterized image quality in terms of detection accuracy and scan parameters. For each case, expert pediatric radiologists examined the images to detect lung nodules representing pulmonary metastatic diseases.

After analyzing the data, the researchers found that CT protocols could be improved by assessing the relationship between radiation dose and diagnostic accuracy across a range of pediatric sizes. Before optimization, protocols using a similar dose resulted in an accuracy ranging from 89 percent for the youngest patients to 67 percent for the oldest patients. When the researchers used optimized individual scan parameters, they achieved a consistent accuracy of 83 percent across patient age/size categories using a wide range of radiation doses.

“This work is among the first to combine realistic measures of task-based image quality and patient risk to help guide optimization of CT acquisition settings,” said Adam Alessio, a professor of radiology at the University of Washington in Seattle. “The primary take-away from this work is that as dose increases, there is a patient-specific and task-specific amount of dose where diagnostic performance plateaus and further increases in dose result in no real performance gains.”

Although additional studies are needed, the authors suggest that their framework could be applied to other imaging systems and clinical tasks. “We hope that the technology can be put to use by other medical centers, and further commercialized in near future,” Samei said. “It is ready for clinical translation, and we are in the process of precisely doing so in the follow-up projects underway.”

But other experts remain concerned about the cost-effectiveness and practicality of this approach. “This is a pretty complicated paper. I am not sure this can be incorporated into routine clinical practice,” said Eric J. Hall, a special research scientist at the Center for Radiological Research at Columbia University Medical Center in New York.

According to Keith Strauss, a clinical imaging physicist at Cincinnati Children’s Hospital Medical Center in Ohio, the new method is more rigorous than previous, simpler approaches. “However, these simpler approaches usually result in the correction of the majority of the problems,” he said. “Ideally, patient size, dose, and image quality should be rigorously addressed on all CT scanners, but this may only be possible in academic centers with extensive support in the clinic from medical physicists. There is always a point of diminishing returns. Just because we can do something in the clinic does not always mean we should do it.”

Janelle Weaver, Contributor | bit.ly/2zGZnCx | Mon, 10/02/2017

When You Think It’s the Shunt Causing a Problem, What’s the Most Cost-Effective Way to Know That?

When a child with an intracranial shunt comes into the ED more irritable than normal, one cannot help but worry if the shunt has become blocked or disconnected. So how do you know? What is the best way to diagnose an intracranial shunt problem?  Pershad et al. ( 10.1542/peds.2016-4263) decided to compare the cost-effectiveness of several imaging modalities including CT scan, fast sequence MRI and ultrasound of optic nerve sheath diameter.  The authors share the results of four diagnostic imaging strategies, including CT alone, MRI alone, ultrasound first followed by CT or ultrasound first followed by MRI. All models were preceded by a plan shunt series and the short and long-term costs of radiation–induced malignancy up the road were factored into their model.  The results of this modelling study suggest that if a plain film series is inconclusive, an ultrasound measurement of optic nerve sheath diameter is the best way to go and if that suggests a problem or if the shunt series suggests a concern, then fast sequence MRI is the preferred most cost effective imaging test rather than CT.  Is this sequence what you or your pediatric neurosurgeon uses to screen for a shunt problem in your patients?  Will it be what you do going forward after reading this study?  We won’t apply pressure and force you to read this study, but you will be heads up above your colleagues and be of great help to families of patients who do have intracranial shunts if you do review the information on cost-effective imaging so you have a sound approach the next time this problem occurs.

Dr Lewis First, MD, MA | July 13, 2017 | http://bit.ly/2yHs17X

Study shows how near-drowning-induced brain injury affects children

Researchers at the University of Texas at San Antonio found that children whose brains are injured from near-drownings maintain certain cognitive capabilities.

The study analyzed 11 children with quadriplegia from near-drowning-induced brain injury using resting-state functional magnetic resonance imaging, or MRI scans.

All of the children were comatose immediately following their near-drowning-induced brain injury and gradually regained consciousness, with varying ability to communicate cognitive state.

The goal of the study, published July 31 in Human Brain Mapping, was to overcome the extremely challenging task of assessing brain function after anoxic brain injury.

Researchers found that children who developed anoxic brain injury due to near-drowning experience severe motor deficits, but maintain relatively intact perceptual and cognitive capabilities.

The study showed children with anoxic brain injury from near-drowning suffer from a selective deefferentation syndrome, in which motor deficits largely underlie their inability to convey intact cognition and perception.

Amy Wallace | Aug. 1, 2017 | http://bit.ly/2h0s9WU