Hans G. Ringertz

ICRP publication 121: radiological protection in paediatric diagnostic and interventional radiology.

Paediatric patients have a higher average risk of developing cancer compared with adults receiving the same dose. The longer life expectancy in children allows more time for any harmful effects of radiation to manifest, and developing organs and tissues are more sensitive to the effects of radiation. This publication aims to provide guiding principles of radiological protection for referring clinicians and clinical staff performing diagnostic imaging and interventional procedures for paediatric patients. It begins with a brief description of the basic concepts of radiological protection, followed by the general aspects of radiological protection, including principles of justification and optimisation. Guidelines and suggestions for radiological protection in specific modalities - radiography and fluoroscopy, interventional radiology, and computed tomography - are subsequently covered in depth. The report concludes with a summary and recommendations. The importance of rigorous justification of radiological procedures is emphasised for every procedure involving ionising radiation, and the use of imaging modalities that are non-ionising should always be considered. The basic aim of optimisation of radiological protection is to adjust imaging parameters and institute protective measures such that the required image is obtained with the lowest possible dose of radiation, and that net benefit is maximised to maintain sufficient quality for diagnostic interpretation. Special consideration should be given to the availability of dose reduction measures when purchasing new imaging equipment for paediatric use. One of the unique aspects of paediatric imaging is with regards to the wide range in patient size (and weight), therefore requiring special attention to optimisation and modification of equipment, technique, and imaging parameters. Examples of good radiographic and fluoroscopic technique include attention to patient positioning, field size and adequate collimation, use of protective shielding, optimisation of exposure factors, use of pulsed fluoroscopy, limiting fluoroscopy time, etc. Major paediatric interventional procedures should be performed by experienced paediatric interventional operators, and a second, specific level of training in radiological protection is desirable (in some countries, this is mandatory). For computed tomography, dose reduction should be optimised by the adjustment of scan parameters (such as mA, kVp, and pitch) according to patient weight or age, region scanned, and study indication (e.g. images with greater noise should be accepted if they are of sufficient diagnostic quality). Other strategies include restricting multiphase examination protocols, avoiding overlapping of scan regions, and only scanning the area in question. Up-to-date dose reduction technology such as tube current modulation, organ-based dose modulation, auto kV technology, and iterative reconstruction should be utilised when appropriate. It is anticipated that this publication will assist institutions in encouraging the standardisation of procedures, and that it may help increase awareness and ultimately improve practices for the benefit of patients.

Global quality imaging : Improvement actions

Workforce shortage, workload increase, workplace changes, and budget challenges are emerging issues around the world, which could place quality imaging at risk. It is important for imaging stakeholders to collaborate, ensure patient safety, improve the quality of care, and address these issues. There is no single panacea. A range of improvement measures, strategies, and actions are required. Examples of improvement actions supporting the 3 quality measures are described under 5 strategies: conducting research, promoting awareness, providing education and training, strengthening infrastructure, and implementing policies. The challenge is to develop long-term, cost-effective, system-based improvement actions that will bring better outcomes and underpin a sustainable future for quality imaging. In an imaging practice, these actions will result in selecting the right procedure (justification), using the right dose (optimization), and preventing errors along the patient journey. To realize this vision and implement these improvement actions, a range of expertise and adequate resources are required. Stakeholders should collaborate and work together. In todays globalized environment, collaboration is strength and provides synergy to achieve better outcomes and greater success.

Standardizing resistive indices in healthy pediatric transplant recipients of adult-sized kidneys.

Gholami S, Sarwal MM, Naesens M, Ringertz HG, Barth RA, Balise RR, Salvatierra O. Standardizing resistive indices in healthy pediatric transplant recipients of adult‐sized kidneys.
Pediatr Transplantation 2010: 14: 126–131.

Globalization of P4 Medicine: Predictive, Personalized, Preemptive, and Participatory—Summary of the Proceedings of the Eighth International Symposium of the International Society for Strategic Studies in Radiology, August 27–29, 2009

In August 2009, the International Society for Strategic Studies in Radiology held its eighth biennial meeting. The program focused on the globalization of predictive medicine--or P4 medicine--as it relates to the practice of radiology and radiology research. P4 medicine refers to predictive, personalized, preemptive, and participatory medicine and was the inspiration of Elias Zerhouni, MD, former director of the National Institutes of Health. This article is a summary of some of the key concepts presented at the meeting by an international group of radiologists, imaging scientists, and leaders of industry. In predictive medicine, imaging and imaging-related technologies will likely play an increasing role in the early detection of disease and, thus, the preemption of the development of advanced, hard-to-treat disease. Research into systems biology and molecular imaging promises to personalize medicine, facilitating the provision of the right care to the right patient at the right time. In participatory medicine, increasing interactions with referring physicians and patients will be helpful in raising awareness and recognition of the role of radiologists and will have a positive effect on professionalism. There is also a need to increase awareness of the vital role of radiologists as imaging and radiation safety experts who evaluate the necessity and appropriateness of examinations, monitor performance quality, and are available for postexamination consultations.

Prenatal diagnosis of horseshoe lung and esophageal atresia

We present a case of horseshoe lung (HL) and esophageal atresia suspected prenatally on US imaging and confirmed with fetal MRI. Prenatal diagnosis of HL and esophageal atresia allowed for prenatal counseling and informed parental decisions.

Side markings of the neonatal chest X-ray: two legal cases of pneumothorax side mix up.

Abstract. Two medicolegal case reports are presented. They involve chest X-ray with left-and-right side confusion due to lack of radio-opaque side markers. Two premature babies with pneumothorax got thoracostomy on the wrong side, in one case with a fatal outcome.

Radiological protection in paediatric computed tomography.

It is well known that paediatric patients are generally at greater risk for the development of cancer per unit of radiation dose compared with adults, due both to the longer life expectancy for any harmful effects of radiation to manifest, and the fact that developing organs and tissues are more sensitive to the effects of radiation. Multiple computed tomography (CT) examinations may cumulatively involve absorbed doses to organs and tissues that can sometimes approach or exceed the levels known from epidemiological studies to significantly increase the probability of cancer development. Radiation protection strategies include rigorous justification of CT examinations and the use of imaging techniques that are non-ionising, followed by optimisation of radiation dose exposure (according to the ‘as low as reasonably achievable’ principle). Special consideration should be given to the availability of dose reduction technology when acquiring CT scanners. Dose reduction should be optimised by adjustment of scan parameters (such as mAs, kVp, and pitch) according to patient weight or age, region scanned, and study indication (e.g. images with greater noise should be accepted if they are of sufficient diagnostic quality). Other strategies include restricting multiphase examination protocols, avoiding overlapping of scan regions, and only scanning the area in question. Newer technologies such as tube current modulation, organ-based dose modulation, and iterative reconstruction should be used when appropriate. Attention should also be paid to optimising study quality (e.g. by image post-processing to facilitate radiological diagnoses and interpretation). Finally, improving awareness through education and advocacy, and further research in paediatric radiological protection are important to help reduce patient dose.

Relative Carotid Blood Flow Measurements in Dogs by High-speed CT: A Preliminary Study

A high-speed computed tomography (CT) scanner was used for measuring flow in a phantom and in the common carotid arteries of six dogs. The general ability of the scanner to assess flow using contrast media boluses was tested with the phantom. The validated simple concept was then used in the animals. The carotid blood flow was varied with a distal occluder on one side and measured with electromagnetic flow probes in both vessels. The results are promising and demonstrate a good correlation between the high-speed CT findings and those measured with the flow probes.

Radiologic protection in pediatric radiology: ICRP recommendations

On Aug. 24, 2011, the US Joint Commission issued a sentinel event alert on radiation risk from diagnostic imaging that could change the way radiology departments are run in the near future [1]. The Joint Commission, cognizant of the benefits of diagnostic imaging, is also aware of the known risks of radiation dose for the development of cancer and the alarming increasing utilization of medical imaging (in particular of CT) over the last decades. The Joint Commission is concerned specifically about potential overutilization and the lack of justification for radiologic exams and suggests raising awareness of the increased risks associated with radiation among providers, equipment manufacturers and patients. The specific actions suggested by the Joint Commission emphasize the main principles of radiation protection: justification and optimization. The Joint Commission also endorses the implementation of a national registry to track radiation doses as the start of a process to identify optimal and reference doses. The International Commission on Radiological Protection (ICRP) has recently issued specific radiation protection recommendations for diagnostic and interventional radiology in the pediatric population [2]. The main purpose of this report is to provide referring physicians and staff performing diagnostic and interventional procedures, as well as equipment vendors, with common and specific pediatric radiation protection guidelines. The ICRP is an independent, nonprofit international organization that has, since 1928, offered recommendations on the principles and practice of radiation protection. The ICRP comprises a main commission and five committees whose members are international leaders in the field of radiation protection. The ICRP is an advisory body and does not provide regulatory text. The recommendations issued by the ICRP are followed widely by international, national, regional and local agencies. Because the implementation of these recommendations is a time-consuming process that requires significant institutional effort, the ICRP avoids making frequent changes to its main recommendations. The ICRP report provides an executive summary focusing on the basic principles of radiation protection: justification and optimization. Every examination performed must be justified and result in a net benefit to the patient. The principle of justification is specially emphasized for image modalities that deliver a relative high dose such as CT and interventional radiology. The report outlines examples of unjustified examinations and emphasizes the importance of using alternative techniques that do not use ionizing radiation when feasible. The document provides examples of organ-system-based referral guidelines to help pediatric radiologists and ordering physicians make a better use of the departments of radiology, improve clinical practice and reduce unnecessary radiation exposure. Optimization of medical exposures in diagnostic and interventional radiology is another fundamental principle of radiation protection and advice and input from medical physicists must be sought. The report outlines ways in which unnecessary dose to patients and operating staff can be minimized during diagnostic and interventional procedures. It also provides specific advice on how technical parameters should be adjusted to deliver sufficient image quality without reducing diagnostic capabilities. The report emphasizes the concept and use of DRLs (diagnostic reference levels) and gives multiple examples of how implementation of quality criteria and R. Sanchez (*) Department of Radiology, C. S. Mott Children’s Hospital, University of Michigan Hospital, 1540 E. Hospital Drive, 3-220, Ann Arbor, MI 48109-4252, USA e-mail: ramonsan@umich.edu

A method for the study of regional ischemic dysfunction in the intact dog. Permanent endocardial markers and the pressure-length loop.

A radiographic method for use in the closed-chest dog is described which allows the quantitation of segmental mechanical performance. Previous work has shown that the area of the pressure-length loop (an approximation of a stress-strain integral) is a useful measure of the mechanical work performed by a segment of myocardium. The position of radiopaque markers previously placed to define segments of myocardium is recorded by biplane cineradiography. From simultaneous measurements of left ventricular pressure the integral of pressure with respect to segment length during one cardiac cycle is calculated. An example illustrating the utility of this model for the study of regional myocardial ischemia is presented.