EH 1_2016

EUROPEAN HOSPITAL  Vol 25 Issue 1/16 20 EH @ ECR Ultrasound contrast agents are considered a medical drug Presenter at ECR calls for more research Child imaging has defined rules Elastography is a promising tool in paediatrics Interview: Sascha Keutel Paediatric imaging is a subspecialty that uses a diverse range of imag- ing systems, from classical X-ray to ultrasound, CT and MR. In an inter- view with Dr Damjana Ključevšek, consultant paediatric radiolo- gist at the Children’s Hospital of the University Medical Centre of Ljubljana, Slovenia, spoke of the challenges and particularities in paediatric imaging, especially in the use of contrast-enhanced ultrasound in children. Asked about the distinct aspects of child imaging, Dr Damjana Ključevšek explained: ‘Paediatric radiologists deal with different developmental stages from foetal life, through early childhood, to adolescence. As the quote goes, “Children are not small adults”. It’s very important to be familiar with their embryology, maturation and growth. Many different diseases occur at different ages, and children with the same disease require a dif- ferent approach at different ages. The International day of Radiology 2015 was dedicated to paediatric radiology, which says a lot about the importance of this imaging sub- specialty. In our country, paediatric imaging includes imaging of foetus, individuals younger than 18, and also young adults in the case of rare chronic diseases (e.g. some storage disease, unusual or very uncommon congenital disorders).’ How do procedures differ from adult imaging? ‘For a child, diagnostic imaging is stressful. He/she is put into an unknown environment, which is noisy, busy, and full of strange equipment. Therefore, the environ- ment should be made as friendly as possible for children, and a sense of trust should be developed between the radiologist, radiographer, child and parents. It’s necessary to take some time and explain to the par- ents, why and how the radiographic procedure is going on. Parents are often actively involved in the pro- cedure: they calm, comfort, and undress the baby, if necessary. ‘During imaging the child’s safety is of highest importance. The first task of the radiologist is to confirm whether the proposed examination is indicated or not, and if the exami- nation answers specific clinical questions. According to the ALARA imaging, to evaluate and follow up chronic hepatic pathologies with fibrosis. The current gold standard to stage liver fibrosis is biopsy, which has its limitations – the need for sedation, invasiveness, interob- server and sampling variability. ‘Currently, most elastography sys- tems are coupled with ultrasound, which is easy to perform in routine practice in children. The interest in (as low as reasonably achievable) principle numerous devices for the child’s protection (lead protection, immobilisation ancillary equipment) and paediatric imaging protocols adapted to different ages and clini- cal questions are used.’ What affects contrast-enhanced ultrasound use in children? ‘First, ultrasound contrast agents (UCAs) in general are not registered for individuals younger than 18 years and their current use is off- label, which makes their application in children questionable, because of legal issues. In our hospital we gained approval from our National this technique is that it reduces the number of liver biopsies. There are other anatomical regions (thyroid, renal, muscular pathologies) that are explored by elastography, but preliminary results have yet to be validated by further studies.’ Are there special considerations for using elastography in paedi- atrics?  Medical Ethics Committee, which allows us to use UCA in children. ‘It’s of major importance to obtain written informed consent signed by parents or the legal child’s caretaker before CEUS, after a detailed expla- nation of the examination, proce- dure, clinical value, and the safety of UCAs. ‘UCAs are not officially available in all countries. On the other hand, there is a need for diagnostic inno- vation and child-friendly imaging in daily clinical routine.’ Are there risks in using Contrast- enhanced ultrasound (CEUS) for children? ‘UCAs are considered a medical drug and there is always a potential risk for side effects. Therefore, the safety issue of UCAs’ in children is very important. The safety of UCAs, either intravenous or intravesical, has been evaluated in several stud- ies. Intravenous application CEUS ‘The most common modality of elastography is coupled with ultra- sound. In children, we have to con- sider some specificities: the choice of probes according to a child’s size, technical experience to obtain valid results with younger children despite movements, crying, and breathing. Also, we now know that, among the different ultrasound elas- tography systems available, some is less widespread, but is slowly gaining popularity among paediatric radiologists as a problem-solving method. Unfortunately, the proce- dure has not been standardised and there are no official recommenda- tions regarding the dose of UCAs, which should be appropriately adjusted according to the patient’s weight or age, the examined organ, and to the probe. ‘Recently, a meta-analysis of adverse effects after intravenous applica- tion of second-generation UCAs was published by Piskunowicz. Only one severe anaphylactoid reaction in a child following the intravenous administration of UCAs has been described, so far. ‘In some children some minor tran- sitional adverse reactions (urtica and rash, a brief alteration of taste sen- sation, mild tinnitus, light-headed- ness) were recorded. The European survey and meta-analysis of Darge et al. evaluated the intravesical use are more adapted to children than others due to the child’s size and difficulty to obtain apnoea. ‘We should also consider the neces- sity to establish normal values for children for different organs.’ Elastography is used on adults mainly for breast and liver: it is the same for children? ‘Although elastography is frequently used in adults for breast and liver imaging, in children it’s been only validated so far, by multiple recent studies, in liver imaging.’ Are there gender differences to consider? ‘There is no difference between boys and girls for elastography val- ues.’ In your presentation, what will be your main points? ‘Already used in adults for sever- al years, elastography is a prom- ising tool in paediatric imag- ing,’ according to radiologist Dr Mehrak Anooshiravani-Dumont, from Geneva University Hospital. ‘It allows detection of changes in the mechanical properties of tissues, such as fibrosis, based on viscoelas- tic characteristics. ‘The technique is so far validated in paediatric liver Voiding urosound comment: Contrast-enhanced voiding ultrasound (VUS): ultrasound contrast agent is seen in pelvicalyceal system (white arrows) in right kidney. Vesicoureteric reflux grade III is confirmed CEUS liver comment: Contrast-enhanced ultrasound (CEUS) of liver as a problem solving method: hypo-echoic lesion in fatty liver (white arrows), seen on ultrasound, was confirmed to be focally spared area of fatty liver infiltration. During the CEUS, uniform enhancement of lesion similar to normal liver parenchyma was observed. No further diagnostic imaging is necessary ARFI VTIQ normal values: blue colour in the liver parenchyma ARFI VTIQ high values with red colour in severe fibrosis ARFI VTQ in the liver: normal value CEUS kidney cyst: During CEUS examination the complex kidney cyst was graded as Bosniac III: enhancement of cyst septas and cyst nodule ECR 2016 Friday 4 March 4:00–5:30 p.m. Room M3 Expanding horizons in paediatric imaging (also see lecture above)

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