Blunt abdominal trauma: diagnostic performance of contrast-enhanced US in children--initial experience

A Preliminary Study on the Application of Contrast-Enhanced Ultrasonography in Children With Peripheral Neuroblastic Tumors

The purpose of this study was to retrospectively analyze the characteristics of contrast-enhanced ultrasound (CEUS) images and quantitative parameters of time-intensity curves (TICs) in children's peripheral neuroblastic tumors (pNTs). By comparing the imaging features and quantitative parameters of the TICs of neuroblastoma (NB) and ganglioneuroblastoma (GNB) patients, we attempted to identify the distinguishing points between NB and GNB. A total of 35 patients confirmed to have pNTs by pathologic examination were included in this study. Each child underwent CEUS with complete imaging data (including still images and at least 3 min of video files). Twenty-four patients were confirmed to have NB, and 11 were considered to have GNB according to differentiation. The CEUS image features and quantitative parameters of the TICs of all lesions were analyzed to determine whether there were CEUS-related differences between the two types of pNT. There was a significant difference in the enhancement patterns of the CEUS features (χ2 = 5.303, p < 0.05), with more "peripheral-central" enhancement in the NB group and more "central-peripheral" enhancement in the GNB group. In the TIC, the rise time and time to peak were significantly different (p < 0.05). The receiver operating characteristic curve showed that the probability of ganglion cell NB increased significantly after RT > 15.29, with a sensitivity of 0.636 and a specificity of 0.958. When the peak time was greater than 16.155, the probability of NB increased significantly, with a sensitivity of 0.636 and a specificity of 0.958. The CEUS features of NB and GNB patients are very similar, and it is difficult to distinguish them. Rise time and time to peak may be useful in identifying GNB and NB, but the sample size of this study was small, and the investigation was only preliminary; a larger sample size is needed to support these conclusions.

Contrast-enhanced ultrasound (CEUS) in the follow-up of abdominal solid organ trauma: an international survey prior to the PseAn study

BACKGROUND

The blunt and penetrating abdominal trauma follow-up relies on contrast CT scan to detect solid organ injuries. CEUS is not widely used worldwide, despite its accuracy and feasibility in identifying parenchymal and vascular lesions. This survey aims to define the current use of CEUS in Trauma Centers and the expectations of Emergency Surgeons regarding its role.

METHODS

We sent an online questionnaire composed of 10 questions to trauma physicians worldwide during the period of September 2022 to March 2023.

RESULTS

59 participants from 53 different centers answered the questionnaire. 76.2% of the enrolled participants have CEUS available at their Institution, and 49.2% think that it can replace CT scan. Contrast-CT scan remains the preferred option in the follow-up of blunt liver (69.5%), spleen (72.9%) and kidney (76.3%) injuries, followed by CEUS which is used in 18.6% for liver, 20.3% for spleen and 15.3% for kidney injuries. The results are similar for penetrating abdominal trauma, with contrast CT scan being the first-line imaging technique (91.5% for liver, 91.5% for spleen and 88.1% for kidney injuries), followed by CEUS (5.1% for liver, 5.1% for spleen and 6.8% for kidney injuries).

CONCLUSIONS

Our survey shows that CEUS is still underutilized in the follow-up of abdominal trauma, even though many emergency surgeons consider it as a valid alternative to contrast CT scan.

Management of pediatric blunt abdominal trauma with split liver or spleen injuries: a retrospective study

BACKGROUND

Blunt abdominal trauma is a prevailing cause of pediatric morbidity and mortality. It constitutes the most frequent type of pediatric injuries. Contrast-enhanced sonography (CEUS) and contrast-enhanced computed tomography (CECT) are considered pivotal diagnostic modalities in hemodynamically stable patients.

AIM

To report the experience in management of pediatric split liver and spleen injuries using CEUS and CECT.

PATIENTS AND METHODS

This study included 246 children who sustained blunt abdominal trauma, and admitted and treated at three tertiary hospitals in the period of 5 years. Primary resuscitation was offered to all children based on the advanced trauma and life support (ATLS) protocol. A special algorithm for decision-making was followed. It incorporated the FAST, baseline ultrasound (US), CEUS, and CECT. Patients were treated according to the imaging findings and hemodynamic stability.

RESULTS

All 246 children who sustained a blunt abdominal were studied. Patients' age was 10.5 ± 2.1. Road traffic accidents were the most common cause of trauma; 155 patients (63%). CECT showed the extent of injury in 153 patients' spleen (62%) and 78 patients' liver (32%), while the remaining 15 (6%) patients had both injuries. CEUS detected 142 (57.7%) spleen injury, and 67 (27.2%) liver injury.

CONCLUSIONS

CEUS may be a useful diagnostic tool among hemodynamically stable children who sustained low-to-moderate energy isolated blunt abdominal trauma. It may be also helpful for further evaluation of uncertain CECT findings and follow-up of conservatively managed traumatic injuries.

Detection of post-traumatic abdominal pseudoaneurysms by CEUS and CT: A prospective comparative global study (the PseAn study)-study protocol

The success of non-operative management in trauma increased with the availability of new-generation CT scan machines, endoscopy, and angiography, becoming the standard of care in hemodynamically stable trauma patients with abdominal solid organ injuries, with a success rate of 78% to 98%. Post-traumatic pseudoaneurysms (PAs) can develop at any region of an injured artery and they may cause delayed bleeding in splenic or hepatic trauma, with an incidence in patients treated with NOM of 2%-27% and 1.2%-6.1% respectively. Diagnosis is made by angiography, contrast-enhanced computer tomography (CT), or Doppler Ultrasound (US) while the use of contrast-enhanced ultrasound (CEUS), has increased in recent years although few data are available about CEUS feasibility in the follow-up setting. The PseaAn study has been designed to assess the role of CEUS in the follow-up of abdominal trauma by defining its sensitivity, specificity and predictive values compared with abdominal CT scan. The PseAn study is a multi-centric international diagnostic cross-sectional study initiated by the Level I Trauma Center of the Niguarda Ca' Granda Hospital in Milan, Italy. To study the role of CEUS in detecting post-traumatic splenic, hepatic, and renal PAs compared with the gold standard of CT with intravenous contrast at different follow-up time points, and whether it can replace CT scan in the follow-up of solid organ injuries, patients with OIS III and above will undergo a follow-up with both a CEUS and CT scan to detect post-traumatic parenchymal pseudoaneurysm within two to five days from injury. The use of CEUS in the follow-up of abdominal trauma follow-up (particularly blunt trauma) has increased, to minimise the use of ionizing radiation and contrast media and encouraging results have been published during the last decade showing that CEUS is an accurate technique for evaluating traumatic lesions of solid abdominal organs. Conclusions We think that CEUS, which is underused worldwide, is a useful and safe tool that may replace CT scan in follow-up with the major advantage of reduced radiation. Our current study may give stronger evidence to support this view.

Contrast-enhanced ultrasound in pediatric blunt abdominal trauma: a systematic review

PURPOSE

Intra-abdominal injury is a major cause of morbidity in children. Computed tomography (CT) is the reference standard for the evaluation of hemodynamically stable abdominal trauma. CT has an increased risk of long-term radiation induced malignancies and a possible risk associated with the use of iodinated contrast media. Contrast-enhanced ultrasound (CEUS) might represent an alternative to CT in stable children with blunt abdominal trauma (BAT). Nonetheless, CEUS in pediatrics remains limited by the lack of strong evidence. The purpose of this study was to offer a systematic review on the use of CEUS in pediatric abdominal trauma.

METHODS

Electronic search of PubMed, EMBASE and Cochrane databases of studies investigating CEUS for abdominal trauma in children. The risk of bias was assessed using the ROBINS-I tool.

RESULTS

This systematic review included 7 studies. CEUS was performed with different ultrasound equipment, always with a curvilinear transducer. Six out of seven studies used a second-generation contrast agent. No immediate adverse reactions were reported. The dose of contrast agent and the scanning technique varied between studies. All CEUS exams were performed by radiologists, in the radiology department or at the bedside. No standard training was reported to become competent in CEUS. The range of sensitivity and specificity of CEUS were 85.7 to 100% and 89 to 100%, respectively.

CONCLUSION

CEUS appears to be safe and accurate to identify abdominal solid organ injuries in children with BAT. Further research is necessary to assess the feasibility of CEUS by non-radiologists, the necessary training, and the benefit-cost ratio of CEUS as a tool to potentially reduce CT scans.

Pediatric contrast-enhanced ultrasound: shedding light on the pursuit of approval in the United States

For two decades, pediatric contrast US has been well accepted throughout Europe and other parts of the world outside the United States because of its high diagnostic efficacy and extremely favorable safety profile. This includes intravenous (IV) administration, contrast-enhanced US (CEUS) and the intravesical application, contrast-enhanced voiding urosonography (ceVUS). However, the breakthrough for pediatric contrast US in the United States did not come until 2016, when the U.S. Food and Drug Administration (FDA) approved the first pediatric indication for a US contrast agent. This initial approval covered the use of Lumason (Bracco Diagnostics, Monroe Township, NJ) for the evaluation of focal liver lesions via IV administration in children. A second pediatric indication followed shortly thereafter, when the FDA extended the use of Lumason for assessing known or suspected vesicoureteral reflux via intravesical application in children. Both initial pediatric approvals were granted without prospective pediatric clinical trials, based instead on published literature describing favorable safety and efficacy in children. Three years later, in 2019, the FDA approved Lumason for pediatric echocardiography following a clinical trial involving a total of 12 subjects at 2 sites. The story of how we achieved these FDA approvals spans more than a decade and involves the extraordinary dedication of two professional societies, namely the International Contrast Ultrasound Society (ICUS) and the Society for Pediatric Radiology (SPR). Credit also must be given to the FDA staff for their commitment to the welfare of children and their openness to compelling evidence that contrast US is a safe, reliable, radiation-free imaging option for our pediatric patients. Understanding the history of this approval process will impact the practical application of US contrast agents, particularly when expanding off-label indications in the pediatric population. This article describes the background of the FDA's approval of pediatric contrast US applications to better illuminate the potential pathways to approvals of future indications.

Contrast-enhanced ultrasound: a comprehensive review of safety in children

Contrast-enhanced ultrasound (CEUS) has been increasingly used in pediatric radiology practice worldwide. For nearly two decades, CEUS applications have been performed with the off-label use of gas-containing second-generation ultrasound contrast agents (UCAs). Since 2016, the United States Food and Drug Administration (FDA) has approved the UCA Lumason for three pediatric indications: the evaluation of focal liver lesions and echocardiography via intravenous administration and the assessment of vesicoureteral reflux via intravesical application (contrast-enhanced voiding urosonography, ceVUS). Prior to the FDA approval of Lumason, numerous studies with the use of second-generation UCAs had been conducted in adults and children. Comprehensive protocols for clinical safety evaluations have demonstrated the highly favorable safety profile of UCA for intravenous, intravesical and other intracavitary uses. The safety data on CEUS continue to accumulate as this imaging modality is increasingly utilized in clinical settings worldwide. As of August 2021, 57 pediatric-only original research studies encompassing a total of 4,518 children with 4,906 intravenous CEUS examinations had been published. As in adults, there were a few adverse events; the majority of these were non-serious, although very rarely serious anaphylactic reactions were reported. In the published pediatric-only intravenous CEUS studies included in our analysis, the overall incidence rate of serious adverse events was 0.22% (10/4,518) of children and 0.20% (10/4,906) of all CEUS examinations. Non-serious adverse events from the intravenous CEUS were observed in 1.20% (54/4,518) of children and 1.10% (54/4,906) of CEUS examinations. During the same time period, 31 studies with the intravesical use of UCA were conducted in 12,362 children. A few non-serious adverse events were encountered (0.31%; 38/12,362), but these were most likely attributable to the bladder catheterization rather than the UCA. Other developing clinical applications of UCA in children, including intracavitary and intralymphatic, are ongoing. To date, no serious adverse events have been reported with these applications. This article reviews the existing pediatric CEUS literature and provides an overview of safety-related information reported from UCA uses in children.

Contrast-enhanced ultrasound of blunt abdominal trauma in children

Trauma is the leading cause of morbidity and mortality in children, and rapid identification of organ injury is essential for successful treatment. Contrast-enhanced ultrasound (CEUS) is an appealing alternative to contrast-enhanced CT in the evaluation of children with blunt abdominal trauma, mainly with respect to the potential reduction of population-level exposure to ionizing radiation. This is particularly important in children, who are more vulnerable to the hazards of ionizing radiation than adults. CEUS is useful in hemodynamically stable children with isolated blunt low- to moderate-energy abdominal trauma to rule out solid organ injuries. It can also be used to further evaluate uncertain contrast-enhanced CT findings, as well as in the follow-up of conservatively managed traumatic injuries. CEUS can be used to detect abnormalities that are not apparent by conventional US, including infarcts, pseudoaneurysms and active bleeding. In this article we present the current experience from the use of CEUS for the evaluation of pediatric blunt abdominal trauma, emphasizing the examination technique and interpretation of major abnormalities associated with injuries in the liver, spleen, kidneys, adrenal glands, pancreas and testes. We also discuss the limitations of the technique and offer a review of the major literature on this topic in children, including an extrapolation of experience from adults.

European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB): An Update on the Pediatric CEUS Registry on Behalf of the "EFSUMB Pediatric CEUS Registry Working Group"

The European Federation of Ultrasound in Medicine and Biology (EFSUMB) created the "EFSUMB Pediatric Registry" (EFSUMB EPR) with the purpose of collecting data regarding the intravenous application of pediatric contrast-enhanced ultrasound (CEUS). The primary aim was to document the current clinical practice and usefulness of the technique and secondarily to assess CEUS safety in children. We issue the preliminary results of this database and examine the overall practice of CEUS in children in Europe.

Evaluation of the abdomen in the setting of suspected child abuse

Abusive intra-abdominal injuries are less common than other types of injuries, such as fractures and bruises, identified in victims of child physical abuse, but they can be deadly. No single abdominal injury is pathognomonic for abuse, but some types and constellations of intra-abdominal injuries are seen more frequently in abused children. Identification of intra-abdominal injuries can be important clinically or forensically. Injuries that do not significantly change clinical management can still elevate a clinician's level of concern for abuse and thereby influence subsequent decisions affecting child protection efforts. Abusive intra-abdominal injuries can be clinically occult, necessitating screening laboratory evaluations to inform decisions regarding imaging. Once detected, consideration of developmental abilities of the child, type and constellation of injuries, and the forces involved in any provided mechanism of trauma are necessary to inform assessments of plausibility of injury mechanisms and level of concern for abuse. Here we describe the clinical, laboratory and imaging evaluation of the abdomen in the setting of suspected child abuse.

Contrast-Enhanced Ultrasound in Children: Implementation and Key Diagnostic Applications

Contrast-enhanced ultrasound (CEUS) utilization is expanding rapidly, particularly in children, in whom the modality offers important advantages of dynamic evaluation of the vasculature, portability, lack of ionizing radiation, and lack of need for sedation. Accumulating data establish an excellent safety profile of ultrasound contrast agents in children. Although only FDA-approved for IV use in children for characterizing focal liver lesions and for use during echocardiography, growing off-label applications are expanding the diagnostic potential of ultrasound. Focal liver lesion evaluation is the most common use of CEUS, and the American College of Radiology Pediatric LI-RADS Working Group recommends including CEUS for evaluation of a newly discovered focal liver lesion in many circumstances. Data also support the role of CEUS in hemodynamically stable children with blunt abdominal trauma, and CEUS is becoming a potential alternative to CT in this setting. Additional potential applications that require further study include evaluation of pathology in the lung, spleen, brain, pancreas, bowel, kidney, female pelvis, and scrotum. This review explores the implementation of CEUS in children, describing basic principles of ultrasound contrast agents and CEUS technique and summarizing current and potential IV diagnostic applications based on pediatric-specific supporting evidence.

Paediatric gastrointestinal and hepatobiliary radiology: why do we need subspecialists, and what is new?

We present the case for subspecialisation in paediatric gastrointestinal and hepato-pancreatico-biliary radiology. We frame the discussion around a number of questions: What is different about the paediatric patient and paediatric gastrointestinal system? What does the radiologist need to do differently? And finally, what can be translated from these subspecialty areas into everyday practice? We cover conditions that the sub-specialist might encounter, focusing on entities such as inflammatory bowel disease and hepatic vascular anomalies. We also highlight novel imaging techniques that are a focus of research in the subspecialties, including contrast-enhanced ultrasound, MRI motility, magnetisation transfer factor, and magnetic resonance elastography.

Traumatic Gallbladder Perforation in Children - Case Report and Review

BACKGROUND

 Gallbladder perforation is a very rare finding in children. Clinical and radiografic presentations are often vague. Hence it is a challenging diagnosis, often missed during initial evaluation with potentially fatal consequences. The aim of this case report and review was to identify factors that might help to diagnose and manage future cases.

METHODS

 We present a case of gallbladder perforation in an 8-year-old child after blunt abdominal trauma caused by a handlebar in which imaging modalities such as ultrasound and magnetic resonance imaging (MRI) helped us to determine proper management. We identified and evaluated comparable cases for isolated traumatic gallbladder injury. A review of the recent literature was performed by online search in Pubmed and Google Scholar using "gallbladder injury in children", "gallbladder perforation children", "blunt abdominal trauma children" as keywords. We focused on articles exclusively in the pediatric section. The literature from the period 2000-2020 was taken into account to review the state of the art in diagnosis and management.

RESULTS AND CONCLUSION

 Recent literature for gallbladder injury in pediatrics is sparse compared to the adult counterpart. Only eight published cases of isolated gallbladder injury in children were identified. Since the onset of symptoms may not develop acutely and often develops in an indistinct manner, radiografic examinations play an important role in the diagnostic progress. The authors advise caution in cases of blunt abdominal trauma especially involving handlebars, intraperitoneal free fluid, and severe abdominal pain. We advocate high suspicion of gallbladder perforation if the gallbladder wall displays discontinuation or cannot be definitively differentiated in sonografic examination. Echogenic fluid within the gallbladder should always lead to suspicion of intraluminal bleeding. Repeated clinical and imaging examinations are mandatory since the onset of signs and symptoms may be delayed.

KEY POINTS

  · Awareness of gallbladder perforation in blunt abdominal trauma of the upper abdomen.. · Particularly high index of suspicion in cases involving handlebar injuries.. · Repeated clinical and imaging examinations are highly recommended..

CITATION FORMAT

· Le MT, Herrmann J, Groth M et al. Traumatic Gallbladder Perforation in Children - Case Report and Review. Fortschr Röntgenstr 2021; 193: 889 - 897.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

The predictive role of amylase and lipase levels on pancreas injury diagnosis in patients with blunt abdominal trauma

Objectives Despite the low incidence of pancreatic injury in the abdominal blunt trauma (BTA), its early diagnosis is very important; since pancreatic injury is associated with high rates of morbidity and mortality. However, due to the high association of pancreatic injury with injury of other abdominal organs, its diagnosis may be delayed and complicated. The use of imaging modalities is also subject to limitations for reasons such as cost, unavailability, and harmfulness. Consequently, the present study aimed to investigate the predictive role of amylase and lipase enzyme levels in the final diagnosis of pancreatic injury in patients with BTA. Methods In a prospective diagnostic study, 384 patients with BTA referring to Imam Khomeini hospital of Sari (north of Iran) were enrolled according to the inclusion and exclusion criteria. Initial patient data including age and sex were recorded. Blood samples were analyzed in the laboratory to measure complete blood count (CBC), amylase and lipase enzyme levels. Patients were followed up during hospitalization and focal ultrasound for abdominal trauma (FAST), CT-Scan and laparotomy results were recorded. Finally, the data was analyzed using SPSS version 22. Results The level of amylase enzyme was significantly higher in males (p = 0.04), but the level of lipase enzyme was not significantly different between two genders (p > 0.05). The most common symptoms and signs in patients were pain, tenderness, and hematoma, respectively. The frequency of pancreatic injury in all patients with blunt abdominal trauma was 7.5% based of FAST, 7% based on CT-Scan and 12.4% based on laparotomy. Comparison of laboratory findings based on FAST, CT-Scan and laparotomy results showed that the level of amylase and lipase enzymes in patients with internal organ and pancreatic damage were higher than in patients without internal organ injury (p < 0.05). But based on FAST results; patients with pancreatic injury and injury of other organs had no significant difference (p > 0.05). However, comparison of laboratory findings based on CT-Scan and laparotomy results showed a significant increase in the level of amylase and lipase enzymes in patients with pancreatic trauma compared to patients with injury of other organs (p < 0.001). Conclusions The results of this study showed that pancreatic injury in blunt trauma is associated with a significant increase in levels of amylase and lipase enzymes. In addition, an increase in levels of amylase and lipase enzymes is associated with internal organ damage. Serum amylase and lipase levels can be used as useful biomarkers to decide whether to perform CT-Scan or laparotomy.

Safety and efficacy of percutaneous microwave ablation for post-procedural haemostasis: a bi-central retrospective study focusing on safety and efficacy

OBJECTIVE

To review safety and efficacy of percutaneous microwave ablation (MWA) for post-procedural haemostasis.

METHODS

Institutional databases retrospective research identified 10 cases of iatrogenic bleeding who underwent percutaneous MWA for post-procedural haemostasis. Ultrasound examination with Doppler and contrast enhancement identified a source of active bleeding prior to ablation; additionally they were used as guiding modality for antenna insertion whilst, post-ablation, assessed the lack of active extravasation. Target locations included liver intercostal space spleen and thyroid gland. Technical success was defined as positioning of the antenna on the desired location. Treatment end point was considered the disappearance of active extravasation in both Doppler imaging and contrast-enhanced ultrasound.

RESULTS

Technical success (i.e. positioning of the antenna on the desired location) was achieved in all cases. No complications were noted. All patients post MWA remained haemodynamically stable with no need for transfusion and were discharged from the hospital the next morning. Imaging and clinical follow-up in all patients before exiting the hospital did not depict any sign of active extravasation or bleeding.

CONCLUSION

Our limited experience reports preliminary data showing that MWA could be added in the armamentarium of percutaneous therapies for iatrogenic bleeding. More prospective studies with larger patient samples are necessary for verification of this technique as well as for drawing broader conclusions in order to evaluate the place of percutaneous ablation in the treatment algorithm of haemorrhage.

ADVANCES IN KNOWLEDGE

Percutaneous ablation might have a role in haemostasis in well-selected cases.

Assessment of cerebral perfusion with contrast-enhanced ultrasound during constriction of the neck mimicking malposition of the BD Odon Device™: a study in newborn piglets

OBJECTIVE

The BD Odon Device™ is a new instrument for operative vaginal birth with potential for preventing maternal, fetal and newborn morbidity/mortality during a complicated second stage of labour. The device is a plastic sleeve with an air chamber inflated around the baby's head which is gently pulled through the birth canal. The aim was to monitor changes in cerebral circulation during constriction of the neck to evaluate a risk of potential malposition of the device.

DESIGN

Randomised prospective study.

POPULATION OR SAMPLE

Twelve newborn piglets.

METHODS

The anaesthetised piglets were exposed to hypoxia until base excess was -20 mmol/l and/or mean arterial blood pressure had decreased to 20 mmHg. At reoxygenation, an air chamber was inflated around the neck to 300 mmHg and the piglets randomised into three groups: 10 (n = 5), 5 (n = 5) or 2 (n = 2) minutes' occlusion. Cerebral perfusion was evaluated with transcranial contrast-enhanced ultrasound at four time-points, and analysed in the carotid arteries, basal ganglia, cortex and whole brain. Statistical analysis used ANOVA, linear mixed model, Kruskal-Wallis H-test.

MAIN OUTCOME MEASURES

Perfusion parameters; peak intensity, time to peak intensity, upslope, mean transit time, area under the curve.

RESULTS

The haemodynamic response was comparable between groups. Perfusion parameters showed a slight increase at end hypoxia followed by a decrease during occlusion, especially in the cortex (P = 0.00-0.2). After deflation, perfusion returned towards baseline values.

CONCLUSIONS

Simulation of malposition of the Odon Device was performed using a newborn hypoxic piglet model. Considerable compression of the neck vessels was applied, with only a moderate decrease in perfusion and with restoration of haemodynamics/cerebral perfusion after decompression.

TWEETABLE ABSTRACT

Malposition of Odon Device™ in a piglet model revealed a reversible decrease in cerebral perfusion during neck constriction.

ACR Appropriateness Criteria® Hematuria-Child

Hematuria is the presence of red blood cells in the urine, either visible to the eye (macroscopic hematuria) or as viewed under the microscope (microscopic hematuria). The clinical evaluation of children and adolescents with any form of hematuria begins with a meticulous history and thorough evaluation of the urine. The need for imaging evaluation depends on the clinical scenario in which hematuria presents, including the suspected etiology. Ultrasound and CT are the most common imaging methods used to assess hematuria in children, although other imaging modalities may be appropriate in certain instances. This review focuses on the following clinical variations of childhood hematuria: isolated hematuria (nonpainful, nontraumatic, and microscopic versus macroscopic), painful hematuria (ie, suspected nephrolithiasis or urolithiasis), and renal trauma with hematuria (microscopic versus macroscopic). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Contrast-enhanced ultrasound (CEUS) in pediatric blunt abdominal trauma

Baseline ultrasound is the first-choice technique in traumatic hemodynamically stable children, and is essential in the early assessment of unstable patients to detect hemoperitoneum or other potentially fatal conditions. Despite the technological advancements in new ultrasound equipment and the experience of the operators, it is not always possible to rule out the presence of parenchymal traumatic lesions by means of baseline ultrasound nor to suspect them, especially in the absence of hemoperitoneum. For this reason, in the last decades, basic ultrasound has been associated with contrast-enhanced ultrasound (CEUS) to evaluate the stable little patient in cases such as low-energy blunt abdominal trauma. Because it relies on second-generation contrast agents, the CEUS technique allows for better detection of parenchymal injuries. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients affected by low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. A very important point in favor of CEUS is its capacity to help distinguish the healthy patient, who can be discharged, from the one needing prolonged monitoring, operative management or hospitalization. Finally, we also have the ability to follow-up on low-grade traumatic lesions using CEUS, always keeping in mind patients' clinical conditions and their hemodynamics.

Point-of-care ultrasonography for diagnosing thoracoabdominal injuries in patients with blunt trauma

BACKGROUND

Point-of-care sonography (POCS) has emerged as the screening modality of choice for suspected body trauma in many emergency departments worldwide. Its best known application is FAST (focused abdominal sonography for trauma). The technology is almost ubiquitously available, can be performed during resuscitation, and does not expose patients or staff to radiation. While many authors have stressed the high specificity of POCS, its sensitivity varied markedly across studies. This review aimed to compile the current best evidence about the diagnostic accuracy of POCS imaging protocols in the setting of blunt thoracoabdominal trauma.

OBJECTIVES

To determine the diagnostic accuracy of POCS for detecting and excluding free fluid, organ injuries, vascular lesions, and other injuries (e.g. pneumothorax) compared to a diagnostic reference standard (i.e. computed tomography (CT), magnetic resonance imaging (MRI), thoracoscopy or thoracotomy, laparoscopy or laparotomy, autopsy, or any combination of these) in patients with blunt trauma.

SEARCH METHODS

We searched Ovid MEDLINE (1946 to July 2017) and Ovid Embase (1974 to July 2017), as well as PubMed (1947 to July 2017), employing a prospectively defined literature and data retrieval strategy. We also screened the Cochrane Library, Google Scholar, and BIOSIS for potentially relevant citations, and scanned the reference lists of full-text papers for articles missed by the electronic search. We performed a top-up search on 6 December 2018, and identified eight new studies which may be incorporated into the first update of this review.

SELECTION CRITERIA

We assessed studies for eligibility using predefined inclusion and exclusion criteria. We included either prospective or retrospective diagnostic cohort studies that enrolled patients of any age and gender who sustained any type of blunt injury in a civilian scenario. Eligible studies had to provide sufficient information to construct a 2 x 2 table of diagnostic accuracy to allow for calculating sensitivity, specificity, and other indices of diagnostic test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts, and full texts of reports using a prespecified data extraction form. Methodological quality of individual studies was rated by the QUADAS-2 instrument (the revised and updated version of the original Quality Assessment of Diagnostic Accuracy Studies list of items). We calculated sensitivity and specificity with 95% confidence intervals (CI), tabulated the pairs of sensitivity and specificity with CI, and depicted these estimates by coupled forest plots using Review Manager 5 (RevMan 5). For pooling summary estimates of sensitivity and specificity, and investigating heterogeneity across studies, we fitted a bivariate model using Stata 14.0.

MAIN RESULTS

We included 34 studies with 8635 participants in this review. Summary estimates of sensitivity and specificity were 0.74 (95% CI 0.65 to 0.81) and 0.96 (95% CI 0.94 to 0.98). Pooled positive and negative likelihood ratios were estimated at 18.5 (95% CI 10.8 to 40.5) and 0.27 (95% CI 0.19 to 0.37), respectively. There was substantial heterogeneity across studies, and the reported accuracy of POCS strongly depended on the population and affected body area. In children, pooled sensitivity of POCS was 0.63 (95% CI 0.46 to 0.77), as compared to 0.78 (95% CI 0.69 to 0.84) in an adult or mixed population. Associated specificity in children was 0.91 (95% CI 0.81 to 0.96) and in an adult or mixed population 0.97 (95% CI 0.96 to 0.99). For abdominal trauma, POCS had a sensitivity of 0.68 (95% CI 0.59 to 0.75) and a specificity of 0.95 (95% CI 0.92 to 0.97). For chest injuries, sensitivity and specificity were calculated at 0.96 (95% CI 0.88 to 0.99) and 0.99 (95% CI 0.97 to 1.00). If we consider the results of all 34 included studies in a virtual population of 1000 patients, based on the observed median prevalence (pretest probability) of thoracoabdominal trauma of 28%, POCS would miss 73 patients with injuries and falsely suggest the presence of injuries in another 29 patients. Furthermore, in a virtual population of 1000 children, based on the observed median prevalence (pretest probability) of thoracoabdominal trauma of 31%, POCS would miss 118 children with injuries and falsely suggest the presence of injuries in another 62 children.

AUTHORS' CONCLUSIONS

In patients with suspected blunt thoracoabdominal trauma, positive POCS findings are helpful for guiding treatment decisions. However, with regard to abdominal trauma, a negative POCS exam does not rule out injuries and must be verified by a reference test such as CT. This is of particular importance in paediatric trauma, where the sensitivity of POCS is poor. Based on a small number of studies in a mixed population, POCS may have a higher sensitivity in chest injuries. This warrants larger, confirmatory trials to affirm the accuracy of POCS for diagnosing thoracic trauma.

Role of contrast-enhanced ultrasound (CEUS) in the diagnosis and management of traumatic splenic injuries

Splenic injuries are common emergencies in the setting of abdominal trauma, as the spleen is the second most frequently injured abdominal organ after the liver. The treatment of splenic injuries underwent a severe shift from operative to non-operative due to an increased awareness of the double physiological function, both immunological and hematological, of the spleen. This, in turn, led to an increased application of splenic preservation techniques. The non-operative approach has been strengthened through radiological imaging and interventional radiology. While multidetector computed tomography is mandatory in the evaluation of hemodynamically stable patients after high-energy trauma, one ultrasound (US) can be used as a first-line technique to examine patients in cases of low-energy trauma. Unfortunately, baseline US has low sensitivity in the detection of traumatic injuries. With the introduction of contrast-enhanced ultrasound (CEUS) as a reliable alternative to baseline ultrasound for low-grade abdominal trauma, the sensitivity of the US technique in recognizing traumatic abdominal lesions has strongly increased, reaching levels of accuracy similar to those of the CT. It has also been strongly recommended for use with children, as it allows for the performance of imaging techniques with the lowest dose of radiation possible. In this review, the authors aim to present the typical appearance of traumatic splenic injuries, using enhanced CEUS capability to overcome baseline US limits, and to describe the different techniques applied according to the hemodynamic stability of the patient.

Emergency and critical care applications for contrast-enhanced ultrasound

INTRODUCTION

Contrast-enhanced ultrasound (CEUS) using intravascular microbubbles has potential to revolutionize point-of-care ultrasonography by expanding the use of ultrasonography into clinical scenarios previously reserved for computed tomography (CT), magnetic resonance imaging, or angiography.

METHODS

We performed a literature search and report clinical experience to provide an introduction to CEUS and describe its current applications for point-of-care indications.

RESULTS

The uses of CEUS include several applications highly relevant for emergency medicine, such as solid-organ injuries, actively bleeding hematomas, or abdominal aortic aneurysms. Compared with CT as the preeminent advanced imaging modality in the emergency department, CEUS is low cost, radiation sparing, repeatable, and readily available. It does not require sedation, preprocedural laboratory assessment, or transportation to the radiology suite.

CONCLUSIONS

CEUS is a promising imaging technique for point-of-care applications in pediatric and adult patients and can be applied for patients with allergy to CT contrast medium or with impaired renal function. More high-quality CEUS research focusing on accuracy, patient safety, health care costs, and throughput times is needed to validate its use in emergency and critical care settings.

Implementation of clinical effectiveness guidelines for solid organ injury after trauma: 10-year experience at a level 1 pediatric trauma center

BACKGROUND

Diagnostic imaging of pediatric blunt abdominal trauma is evolving in light of increased attention to radiation exposure. We hypothesize that the implementation of imaging guidelines has reduced total CT scans without missing clinically significant injury.

METHODS

We retrospectively reviewed blunt trauma patients age 0-17 with solid organ injury who underwent CT scan at our academic level 1 pediatric trauma center between 2005 and 2014. Variables including total annual trauma admissions and CT scans, demographics, injury characteristics, and procedures were recorded. Descriptive statistics, Fisher exact and rank sum testing were performed. p<0.05 defined significance.

RESULTS

Overall percentage of abdominal CT scans decreased significantly after protocol implementation. There were 498 solid organ injuries in 403 subjects. There was a significant decrease in the median percentage of low grade injuries (1.3% versus 0.6%; p=0.019) but no difference in high grade injuries (1.3% versus 1.1%; p=0.394). No patient had death, readmission or delayed diagnosis of injury requiring intervention.

CONCLUSION

Implementation of imaging guidelines for blunt abdominal trauma decreased the incidence of low grade solid organ injuries at our institution, but did not inhibit diagnosis and safe management of high grade injuries. Selective imaging of trauma patients decreases childhood radiation exposure and does not result in delayed bleeding or death.

LEVEL OF EVIDENCE

Level III, retrospective study.

Point-of-Care Ultrasound in Trauma

The use of point-of-care ultrasound in trauma is widespread. Focused Assessment with Sonography for Trauma examination is a prototypical bedside examination used by the treating provider to quickly determine need for intervention and appropriate patient disposition. The role of bedside ultrasound in trauma, however, has expanded beyond the Focused Assessment with Sonography for Trauma examination. Advancements in diagnostics include contrast-enhanced ultrasound, thoracic, and musculoskeletal applications. Ultrasound is also an important tool for trauma providers for procedural guidance including vascular access and regional anesthesia. Its portability, affordability, and versatility have made ultrasound an invaluable tool in trauma management in resource-limited settings. In this review, we discuss these applications and the supporting evidence for point-of-care ultrasound in trauma.

Fast hemostasis: a win-win strategy for ultrasound and microwave ablation

Introduction

Hemorrhage is a serious complication following percutaneous biopsy requiring detecting and immediate treatment of active bleeding. This study aimed to explore the potential benefits of ultrasound (US)-guided microwave ablation (MWA) to treat acute hemorrhage in risky locations.

Materials and methods

We present seven patients (four males and three females) aged 19–69 years with solid-organ arterial hemorrhage treated by US-guided MWA and followed up with contrast-enhanced US (CEUS).

Results

All seven cases successfully underwent MWA for hemostasis, and their vital signs subsequently stabilized. During the follow-up from 13 to 36 days, the ablation area decreased slowly in five patients and was still stable in two cases. There were no complications observed in this study after MWA treatment. We also reviewed a total of 12 publications in the past 10 years.

Conclusion

This study suggested that US-guided MWA may be an effective and safe strategy for acute hemorrhage in the emergency setting. To confirm this method and benefit more patients, more prospective studies with larger samples and longer follow-ups are recommended.

Contrast enhanced ultrasound for the evaluation of blunt pediatric abdominal trauma

INTRODUCTION

Blunt abdominal trauma is a common problem in children. Computed tomography (CT) is the gold standard for imaging in pediatric blunt abdominal trauma, however up to 50% of CTs are normal and CT carries a risk of radiation-induced cancer. Contrast enhanced ultrasound (CEUS) may allow accurate detection of abdominal organ injuries while eliminating exposure to ionizing radiation.

METHODS

Children aged 7-18years with a CT-diagnosed abdominal solid organ injury underwent grayscale/power Doppler ultrasound (conventional US) and CEUS within 48h of injury. Two blinded radiologists underwent a brief training in CEUS and then interpreted the CEUS images without patient interaction. Conventional US and CEUS images were compared to CT for the presence of injury and, if present, the injury grade. Patients were monitored for contrast-related adverse reactions.

RESULTS

Twenty one injured organs were identified by CT in eighteen children. Conventional US identified the injuries with a sensitivity of 45.2%, which increased to 85.7% using CEUS. The specificity of conventional US was 96.4% and increased to 98.6% using CEUS. The positive predictive value increased from 79.2% to 94.7% and the negative predictive value from 85.3% to 95.8%. Two patients had injuries that were missed by both radiologists on CEUS. In a 100kg, 17year old female, a grade III liver injury was not seen by either radiologist on CEUS. Her accompanying grade I kidney injury was not seen by one of the radiologist on CEUS. The second patient, a 16year old female, had a grade III splenic injury that was missed by both radiologists on CEUS. She also had an adjacent grade II kidney injury that was seen by both. Injuries, when noted, were graded within 1 grade of CT 33/35 times with CEUS. There were no adverse reactions to the contrast.

CONCLUSION

CEUS is a promising imaging modality that can detect most abdominal solid organ injuries in children while eliminating exposure to ionizing radiation. A multicenter trial is warranted before widespread use can be recommended.

LEVEL OF EVIDENCE

Level II; Diagnostic Prospective Study.

Influence of contrast-enhanced ultrasound administration setups on microbubble enhancement: a focus on pediatric applications

BACKGROUND

In pediatrics, contrast-enhanced ultrasound offers high-quality imaging with an excellent safety profile.

OBJECTIVE

To investigate the effects of varying intravenous administration setups on in vitro enhancement and concentration of two commercially available ultrasound contrast agents, taking into consideration potential pediatric applications.

MATERIALS AND METHODS

We quantified in vitro enhancement using a flow phantom (ATS Laboratories, Bridgeport, CT) and Acuson S3000 ultrasound system (Siemens Healthineers, Mountain View, CA) with a 9L4 probe in Cadence pulse sequencing mode. We determined microbubble concentration with an LSRII flow cytometer (BD Biosciences, San Jose, CA). We investigated Optison (GE Healthcare, Princeton, NJ) and Lumason (Bracco, Geneva, Switzerland) ultrasound contrast agents. The ultrasound (US) contrast agent was injected via a 1 mL syringe and flushed with 5 mL of saline through a 22-gauge diffusion catheter (BD Medical, Franklin Lakes, NJ) with the following variations: in-line injection through a 3-way stopcock with and without a neutral displacement connector (ICU Medical, San Clemente, CA), perpendicular through a 3-way stopcock with and without a connector, and without a 3-way stopcock. We also conducted injections through a 22-gauge standard angiocatheter.

RESULTS

Injection through the connector and perpendicular injection via the 3-way stopcock resulted in significant decreases in enhancement for both ultrasound contrast agents (P<0.0001). Injection through the connector resulted in significant decrease in concentration for Optison (P<0.05). Neither addition of the 3-way stopcock (P>0.24) nor use of a pediatric diffusion catheter (P>0.28) affected the enhancement.

CONCLUSION

Ultrasound contrast agent enhancement depends on the administration route, although some effects appear to be specific to the ultrasound contrast agent used. To avoid loss of enhancement, neutral displacement connectors and perpendicular injection should be avoided.

Clinical Applications of Contrast-Enhanced Ultrasound in the Pediatric Work-Up of Focal Liver Lesions and Blunt Abdominal Trauma: A Systematic Review

In pediatrics ultrasound has long been viewed more favorably than imaging that exposes patients to radiation and iodinated contrast or requires sedation. It is child-friendly and diagnostic capabilities have been improved with the advent of contrast-enhanced ultrasound (CEUS). The application of CEUS is indeed promising. However, no ultrasound contrast agent manufactured today is registered for pediatric use in Europe. The contrast agent SonoVue^® has recently been approved by the FDA under the name of Lumason^® to be used in hepatic investigations in adults and children. This article reviews the literature with respect to 2 specific applications of CEUS in children: 1) identification of parenchymal injuries following blunt abdominal trauma, and 2) classification of focal liver lesions. Applications were chosen through the CEUS guidelines published by the European Federation of Societies for Ultrasound in Medicine and Biology and World Federation for Ultrasound in Medicine and Biology. Literature was obtained by searching Medline and Pubmed Central (using Pubmed), Scopus database and Embase. CEUS proved to be an effective investigation in the hemodynamically stable child for identifying parenchymal injuries and for the characterization of focal liver lesions. CEUS showed comparable performance to CT and MRI with a specificity of 98% for identifying benign lesions and a negative predictive value of 100%. For the applications reviewed here, CEUS holds promising perspectives and can help reduce radiation exposure and use of iodinated contrast agents in pediatrics, thereby potentially reducing complications in routine imaging.

Dynamic contrast-enhanced ultrasound of the bowel wall with quantitative assessment of Crohn's disease activity in childhood

Background

Contrast-enhanced ultrasound (CEUS) has become an established non-invasive, patient-friendly imaging technique which improves the characterization of lesions. In addition, dynamic contrast-enhanced ultrasound (DCE-US) provides valuable information concerning perfusion of examined organs. This review addresses current applications of CEUS in children, focused on DCE-US of the bowel wall in patients with Crohn disease, which enables realtime assessment of the bowel wall vascularity with semi-quantitative and quantitative assessment of disease activity and response to medical treatment.

Conclusions

Crohn’s disease is a chronic inflammatory relapsing disease. Frequent imaging re-evaluation is necessary. Therefore, imaging should be as little invasive as possible, children friendly with high diagnostic accuracy. US with wide varieties of techniques, including CEUS/DCE-US, can provide an important contribution for diagnosing and monitoring a disease activity. Even if the use of US contrast agent is off-label in children, it is welcome and widely accepted for intravesical use, and a little less for intravenous use, manly in evaluation of parenchymal lesions. To our knowledge this is the first time that the use of DCE-US in the evaluation of activity of small bowel Crohn disease with quantitative assessment of kinetic parameters is being described in children. Even if the results of the value and accuracy of different quantitative kinetic parameters in published studies in adult population often contradict one another there is a great potential of DCE-US to become a part of the entire sonographic evaluation not only in adults, but also in children. Further control studies should be performed.

Pediatric adrenal trauma: evaluation and follow-up with contrast-enhanced ultrasound (CEUS)

Adrenal trauma is rarely encountered in the pediatric population, often as a component of multi-organ injury and often presenting with hematoma formation. Contrast-enhanced computed tomography (CECT) is the established imaging modality both for initial evaluation and follow-up of patients with blunt abdominal trauma. In children, radiation exposure should be minimized and alternative imaging strategies are needed. Contrast-enhanced ultrasound (CEUS) has recently been successfully used for evaluation of patients with hepatic, renal and splenic injury. We present three cases of children with post-traumatic adrenal hematomas, which were initially diagnosed with CECT and subsequently followed up with CEUS, suggesting that CEUS may be considered for follow-up of adrenal injuries in children. CEUS improves the diagnostic capabilities by increasing tissue contrast and spatial resolution, readily differentiating viable from necrotic tissue in comparison to conventional ultrasound without the risk of iodine contrast agents and ionizing radiation of repeated CECT examinations.

Enhancing the role of paediatric ultrasound with microbubbles: a review of intravenous applications

Contrast-enhanced ultrasound (CEUS) represents a complementary technique to greyscale and colour Doppler ultrasonography which allows for real-time visualization and characterization of tissue perfusion. Its inherent advantages in the child makes ultrasonography an ideal imaging modality; repeatability and good tolerance along with the avoidance of CT, a source of ionizing radiation, renders ultrasonography imaging desirable. Although currently paediatric CEUS is principally used in an "off-label" manner, ultrasonography contrast agents have received regulatory approval for assessment of paediatric focal liver lesions (FLL) in the USA. The safety of ultrasound contrast-agents is well documented in adults, as safe as or even surpassing the safety profile of CT and MR contrast agents. Except for the established intracavitary use of CEUS in voiding urosonography, i.v. paediatric applications have been introduced with promising results in the abdominal trauma initial diagnosis and follow-up, characterization and differential diagnosis of FLL and characterization of lung, pleura, renal and splenic pathology. CEUS has also been used to detect complications after paediatric transplantation, evaluate inflammatory bowel disease activity and assess tumour response to antiangiogenic therapy. The purpose of this review was to present these novel i.v. paediatric applications of CEUS and discuss their value.

Evaluation of the diagnostic accuracy of CEUS in children with benign and malignant liver lesions and portal vein anomalies

OBJECTIVE

Comparison of the diagnostic findings of MRI, CT and CEUS in children with benign and malignant and portal venous anomalies of the liver.

MATERIALS/METHODS

Retrospective analysis of the diagnostic findings of CEUS, MRI and CT scans in 56 children (age 0-17 years) with a total of 60 benign and malignant liver lesions and anomalies of the portal vein/perfusion. All patients underwent CEUS using sulphur hexafluoride microbubbles and a multi-frequency probe (1-5 MHz, 6-9 MHz). Cine-loops were stored up to 3 minutes. MRI was performed in 38 lesions. CT was performed in 8 lesions.

RESULTS

Out of the 56 patients 49 liver lesions (48 benign, 1 malignant), 9 anomalies of the portal vein/perfusion and 2 of the biliary system were detected. 16/49 lesions were analyzed histopathologically. Using CEUS, the characterization of the lesions was possible in 45 out of 49 cases. In 32 cases, CEUS provided the exact diagnosis. Only two benign lesions were falsely categorized as malignant.Findings of MRI and CEUS were concordant in 84% of cases (n = 32/38). CEUS considered 1 benign lesion to be malignant. 2 lesions were not detectable and in 3 lesions no definite diagnosis was established using MRI.Findings of CT and CEUS were concordant in 5 of 8 cases. In 21 lesions CEUS as the only imaging modality was found to be sufficient for diagnostics.

CONCLUSION

Despite the restricted indications for using CEUS in children, it offers a high diagnostic detection rate (93%) for characterization of liver lesions and portal vein anomalies.

Diagnostic imaging of blunt abdominal trauma in pediatric patients

Trauma is a leading cause of morbidity and mortality in childhood, and blunt trauma accounts for 80-90 % of abdominal injuries. The mechanism of trauma is quite similar to that of the adults, but there are important physiologic differences between children and adults in this field, such as the smaller blood vessels and the high vasoconstrictive response, leading to the spreading of a non-operative management. The early imaging of children undergoing a low-energy trauma can be performed by CEUS, a valuable diagnostic tool to demonstrate solid organ injuries with almost the same sensitivity of CT scans; nevertheless, as for as urinary tract injuries, MDCT remains still the technique of choice, because of its high sensitivity and accuracy, helping to discriminate between an intra-peritoneal form a retroperitoneal urinary leakage, requiring two different managements. The liver is the most common organ injured in blunt abdominal trauma followed by the spleen. Renal, pancreatic, and bowel injuries are quite rare. In this review we present various imaging findings of blunt abdominal trauma in children.

Off-Label Use of Ultrasound Contrast Agents for Intravenous Applications in Children: Analysis of the Existing Literature

OBJECTIVES

The purpose of this study was to collect and analyze the published data related to intravenous (IV) use of ultrasound (US) contrast agents in children.

METHODS

We searched the literature to collect all of the published studies reporting the IV administration of a second-generation US contrast agent in children.

RESULTS

We analyzed 9 case series and 5 case reports, as well as 5 individual cases, of pediatric contrast-enhanced US use reported in a study group that also included adults. We found that 502 children underwent contrast-enhanced US examinations (mean age, 9.7 years; range, 1 day-18 years). Most patients (89%) were injected with the sulfur hexafluoride contrast agent SonoVue (Bracco SpA, Milan, Italy). The mean dose used was 1.5 mL (range, 0.1-9.6 mL). Only 10 patients (2%) had adverse reactions related to the contrast agent administration: 1 life-threatening anaphylactic shock and 9 mild transitory adverse effects. We additionally found 38 papers in which the study groups included at least 1 child; thus, we obtained a total of 540 reported cases of off-label use of IV US contrast agents in children. The most frequent target organ was the liver, and most indications were related to space-occupying lesion characterization and abdominal evaluations after blunt trauma. Some studies also evaluated the diagnostic performance of contrast-enhanced US in different clinical scenarios and found very good accuracy. Concordance between contrast-enhanced US imaging and the respective reference-standard imaging methods ranged between 83% and 100% in different studies.

CONCLUSIONS

Our results support the idea that the IV use of US contrast agents in children is safe, feasible, diagnostically robust, and effective.

Post-traumatic liver and splenic pseudoaneurysms in children: Diagnosis, management, and follow-up screening using contrast enhanced ultrasound (CEUS)

BACKGROUND

Pseudoaneurysm (PA) formation following blunt and penetrating abdominal trauma is a recognized complication in solid organ injury, usually diagnosed by contrast-enhanced CT (CECT) imaging. Delayed rupture is a potentially life-threatening event, although its frequency is not known in pediatric trauma. Contrast enhanced ultrasound (CEUS) is a novel radiation-free alternative to CECT with the potential to identify PA.

METHODS

A retrospective review of consecutive cases of significant liver and splenic injuries admitted to single institution (tertiary and quaternary referrals) over more than a 12year period was performed. From 2011, CEUS was performed routinely postinjury (5-10days) using SonoVue™ as contrast. Initially, CECT and CEUS were performed in tandem to ensure accurate correlation.

RESULTS

From January 2002-December 2014, 101 (73M) children [median age was 14.2 (1.3-18)years] with liver and splenic injuries were admitted. Injuries included: liver [n=57, grade 3 (1-5)], splenic [n=35, grade 3 (1-5)], and combined liver/spleen [n=8, (1-4)]. Median Injury Severity Score (ISS) was 13 (2-72). The predominant mechanisms of injury were blunt trauma n=73 (72%) and penetrating trauma n=28 (28%). Seventeen children (17%) developed PA. Six children became symptomatic (35%), and five went on to have embolization [at 7 (3-11)days]. These were detected by CECT (n=4) and CEUS (n=2). Eleven children remained asymptomatic [detected by CECT (n=8) and CEUS (n=3) at median 5 (4-8)days]. One underwent embolization owing to evidence of interval bleeding. Sensitivity of CEUS at detection of PA was 83%, with specificity of 92% (PPV=71%, NPV=96%). There was no association between grade of injury and presence of PA in either liver or splenic trauma (P=0.4), nor was there an association between size of PA and symptoms (P=0.68). Children sustaining splenic PA were significantly younger than those with hepatic PA (P=0.03). Follow-up imaging confirmed resolution of PA in 16 cases. One child was lost to follow-up.

CONCLUSIONS

The incidence of PA is higher than previously reported in the pediatric literature (<5%). Postinjury imaging appears mandatory, and CEUS appears to be highly sensitive and specific for diagnosis and follow-up.

Contrast-enhanced ultrasound (CEUS) in blunt abdominal trauma

Baseline ultrasound is essential in the early assessment of patients with a huge haemoperitoneum undergoing an immediate abdominal surgery; nevertheless, even with a highly experienced operator, it is not sufficient to exclude parenchymal injuries. More recently, a new ultrasound technique using second generation contrast agents, named contrast-enhanced ultrasound (CEUS) has been developed. This technique allows all the vascular phase to be performed in real time, increasing ultrasound capability to detect parenchymal injuries, enhancing some qualitative findings, such as lesion extension, margins and its relationship with capsule and vessels. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients with low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. Several studies demonstrated its ability to detect lesions occurring in the liver, spleen, pancreas and kidneys and also to recognize active bleeding as hyperechoic bands appearing as round or oval spots of variable size. Its role seems to be really relevant in paediatric patients, thus avoiding a routine exposure to ionizing radiation. Nevertheless, CEUS is strongly operator dependent, and it has some limitations, such as the cost of contrast media, lack of panoramicity, the difficulty to explore some deep regions and the poor ability to detect injuries to the urinary tract. On the other hand, it is timesaving, and it has several advantages, such as its portability, the safety of contrast agent, the lack to ionizing radiation exposure and therefore its repeatability, which allows follow-up of those traumas managed conservatively, especially in cases of fertile females and paediatric patients.

Ultrasound: the triage tool in the emergency department: using ultrasound first

Ultrasound in the emergency department has long been recognized as a powerful screening and diagnostic tool for both physicians and radiologists. In the emergency department, since time is of the essence, it becomes a critical tool in triaging patients. Over the years, ultrasound has gained several advantages over other modalities because of its non-ionizing radiation, portability, accessibility, non-invasive method and simpler learning curve. As a result, ultrasound has become one of the most frequently used diagnostic tools in the emergency department by non-radiologists. The value of ultrasound is implemented in every acute ailment in the emergency department such as trauma, acute abdomen, acute pelvic pain, acute scrotal pain, appendicitis in children and acute deep venous thrombosis. Our objective is to discuss the benefit of using ultrasound as the primary modality for each of these diseases.

Comparison between MRI and CEUS in the follow-up of patients with blunt abdominal trauma managed conservatively

INTRODUCTION

Over the past two decades, there has been a shift toward non-operative treatment of patients undergoing a solid organ injury, thus requiring an increasing number of imaging studies to monitor the healing of lesions, which were performed by computed tomography (CT). In consideration of the use of ionizing radiation and contrast media, nowadays there is a trend toward the use contrast-enhanced ultrasound (CEUS) in the follow-up of blunt abdominal trauma. However CEUS has some limits, especially in the assessments of small lesions and in the evaluation of urinary tract lesions and vascular complications. Magnetic resonance imaging (MRI) is a useful alternative, since its lack of use of ionizing radiation, its panoramicity, the possibility to avoid contrast media and the ability to properly evaluate even small lesions. The aim of this study is to evaluate the usefulness and the feasibility of MRI in the follow-up of patients with low-grade blunt abdominal trauma.

MATERIALS AND METHODS

We performed a retrospective review of a cohort including 270 consecutive patients with a history of blunt abdominal trauma; among them, 118 underwent a high-energy trauma, and 152 a low-energy trauma. 124 patients had findings of abdominal injuries at the contrast-enhanced multidetector CT (CE-MDCT), including 68 from the group of major trauma and 56 from the group of minor trauma. 39 patients were operated for incoming lesions. The remaining 85 patients were treated conservatively. Eight patients underwent surgery later for delayed bleeding. The remaining 77 underwent the full follow-up protocol. Follow-up protocol included CEUS at 24 and 72 h and CEUS and MRI at 1 month after trauma; only MRI was performed until the complete resolution.

RESULTS

CEUS at 24-h and at 72-h from trauma showed a very good correlation with onset CE-MDCT in lesions staging. With respect to onset CE-MDCT, CEUS did not identified 2 adrenal injuries and 2 lesions of urinary tract, an intrinsic limit of this technique. CEUS performed at 1 month did not show traumatic lesions in 49/77 of patients. In the remaining 28/77 cases, CEUS demonstrated reduction of the size of the lesions ranging from 25 to 50%. MRI performed at 1 month from trauma did not show traumatic injuries in 37/77 patients; it demonstrated persistence of organ lesion in 40/77 patients. Therefore, in 12/77 patients MRI performed at 1-month demonstrated the persistence of minimal or moderate organ injury, while CEUS was completely negative. In addition, MRI allowed to enhance the persistence of adrenal lesions in 2 cases and the integrity of urinary tract in 2. In the remaining 28 patients, in which both CEUS and MRI showed disease persistence, MRI, however, allowed a better definition of injury extension with respect to CEUS, in terms of dimensions, edges, and morphological evolution.

DISCUSSION AND CONCLUSIONS

MRI allowed to make a better assessment of injuries than CEUS, allowing also a temporal stage of lesions. Infact, there are different evolution stages corresponding to accurate imaging findings. To our knowledge, this is the first study that describes the evolution of blood collection in parenchymal abdominal organs. Therefore, in patients who underwent abdominal traumatic injuries conservatively treated, the follow-up at 1 month can be made by MRI, due to its panoramicity and its high contrast resolution, which allow a better morphological and temporal trauma staging respect to the CEUS.

Contrast-enhanced sonographically guided thermal ablation for treatment of solid-organ hemorrhage: preliminary clinical results

The purpose of this series was to preliminarily evaluate the use of contrast-enhanced sonographically guided percutaneous thermal ablation in the evaluation and treatment of solid-organ bleeding by retrospectively analyzing 6 cases observed in clinical practice. Six patients who underwent contrast-enhanced sonographically guided thermal ablation for treatment of solid-organ bleeding (5 in liver and 1 in spleen) from December 2005 to August 2012 were included in this series. Clinical information, contrast-enhanced sonograms before and after ablation, and the ablation method were retrospectively collected and analyzed. In 5 of the 6 patients, the location of the bleeding lesion was clearly seen. Hemostasis was successfully achieved in 4 of these 5 patients: 1 by radiofrequency ablation and 3 by microwave ablation. Ablation failed to achieve hemostasis in 1 patient who had postbiopsy splenic arterial bleeding because the bleeding vessel was a thick branch of the splenic artery. In the sixth remaining patient, who had bleeding after liver biopsy, hemostasis failed because contrast-enhanced sonography did not precisely locate the bleeding lesion; hence, the ablation zone did not cover the whole lesion. Contrast-enhanced sonographically guided ablation can be an alternative choice for treating solid-organ bleeding because of its effectiveness and minimal invasiveness. However, it should be carefully investigated for those in whom the bleeding lesion cannot be located by contrast-enhanced sonography and in those who have bleeding in a large vessel.

Safety of intravenous application of second-generation ultrasound contrast agent in children: prospective analysis

The goal of the work described here was to assess the safety profile of intravenous second-generation ultrasound contrast agents (UCAs) containing sulfur hexafluoride in pediatric contrast-enhanced ultrasound. Between 2010 and 2013, a total of 167 examinations were performed in 137 children referred by the Oncology Department. Approval by an Independent Ethical Review Board on Scientific Research for the intravenous use of an UCA containing sulfur hexafluoride in children with oncologic diseases was obtained. Consent for UCA administration was acquired from the parents or legal guardians. Severe anaphylactic reaction was observed in 0.6% (n = 1). No other adverse events during or after intravenous administration of contrast were observed in the examined group (no changes in heart rate and rhythm, blood pressure, oxygen saturation or respiratory rate). There were no reports of subjective flushing, nausea, transient headaches or altered taste. Although second-generation ultrasound contrast agents are considered potentially safe, all investigators should be prepared for the development of adverse reactions and have provisions in place for all pediatric intravenous contrast-enhanced ultrasound examinations. More multicenter studies are essential to determination of an accurate UCA safety profile.

Accuracy of contrast-enhanced ultrasound (CEUS) in the identification and characterization of traumatic solid organ lesions in children: a retrospective comparison with baseline US and CE-MDCT

INTRODUCTION

Localized low-energy abdominal trauma is very frequent in the pediatric population. The findings of several studies have shown that ultrasonography (US) can represent a useful and cost-effective tool in the evaluation of blunt abdominal trauma both in adults and children. However, many parenchymal injuries are not correctly visualized at baseline US examination. The introduction of specific US contrast agents contrast-enhanced ultrasound (CEUS) has enabled a better identification of traumatic organ injuries. The correct use of CEUS could therefore identify and select the children who need further diagnostic investigation computed tomography (CT), avoiding unnecessary radiation and iodinated contrast medium exposure. The purpose of our study was to assess the sensibility and feasibility of CEUS in the assessment of low-energy abdominal trauma compared to baseline US in pediatric patients, using contrast-enhanced MDCT as the reference standard.

MATERIALS AND METHODS

We retrospectively reviewed 73 children (51 M and 22 F; mean age 8.7 ± 2.8 years) who presented in our Emergency Department between October 2012 and October 2013, with history of minor abdominal trauma according to the Abbreviated Injury Scale and who underwent US, CEUS, and CE-MDCT. Inclusion criteria were: male or female, aged 0-16, hemodynamically stable patients with a history of minor blunt abdominal trauma. Exclusion criteria were adulthood, hemodynamical instability, history of major trauma. Sensitivity, specificity, PPV, NPV, and accuracy were determined for US and CEUS compared to MDCT.

RESULTS

6/73 patients were negative at US, CEUS, and MDCT for the presence of organ injuries. In the remaining 67 patients, US depicted 26/67 parenchymal lesions. CEUS identified 67/67 patients (67/67) with parenchymal lesions: 21 lesions of the liver (28.8 %), 26 lesions of the spleen (35.6 %), 7 lesions of right kidney (9.6 %), 13 lesions of left kidney. MDCT confirmed all parenchymal lesions (67/67). Thus, the diagnostic performance of CEUS was better than that of US, as sensitivity, specificity, PPV, NPV, and accuracy were 100, 100, 100, 100, and 100 % for CEUS and 38.8, 100, 100, 12.8, and 44 % for US. In some patients CEUS identified also prognostic factors as parenchymal active bleeding in 8 cases, partial devascularization in 1 case; no cases of vascular bleeding, no cases of urinoma. MDCT confirmed all parenchymal lesions. Parenchymal active bleeding was identified in 16 cases, vascular bleeding in 2 cases, urinoma in 2 cases, partial devascularization in 1 case.

CONCLUSIONS

CEUS is more sensitive and accurate than baseline US and almost as sensitive as CT in the identification and characterization of solid organs lesions in blunt abdominal trauma. CT is more sensitive and accurate than CEUS in identifying prognostic indicators, as active bleeding and urinoma. CEUS should be considered as a useful tool in the assessment and monitoring of blunt abdominal trauma in children.

The use of contrast-enhanced ultrasound in blunt abdominal trauma: advantages and limitations

Computed tomography (CT) is the imaging method of choice in the assessment of multiple trauma patients. However, in patients who suffered from low-energy abdominal trauma, the use of CT is controversial, since the probability of injury is low and therefore most of the studies are normal. Thus, conventional US imaging has increasingly been employed as the initial imaging modality in the work-up of minor traumatic emergency condition. More recently, the introduction of a new contrast-enhanced ultrasound (CEUS) technique, using second-generation ultrasound contrast agents, has led to a notable increase in the diagnostic accuracy of US in many organs. Therefore, in trauma patients, following assessment with conventional US imaging, a CEUS exam can be performed, to provide a more reliable assessment of solid organ injuries. CEUS has the potential to detect active bleeding from a variety of traumatic origins. Similar to CT, active extravasation is considered when there is evidence of contrast agent collection with echogenicity similar to that of an adjacent vessel. On the other hand, at least some drawbacks have to be addressed, including operator competence and reduced panoramic view. Moreover, CEUS, like conventional US imaging, cannot depict some lesions, such as diaphragmatic ruptures, bowel, and mesenteric traumatic injuries. This technique represents a non-invasive and repeatable method that can be performed at patient's bedside and is therefore extremely helpful for the follow-up of solid organs traumas managed conservatively, especially in pediatric patients and women of fertile age. Moreover, it may reduce the number of CT scans and expedite patient discharge.

The role of CEUS in the assessment of haemodynamically stable patients with blunt abdominal trauma

Computed tomography (CT) still represents the preferred imaging method in the assessment of patients presenting with multiple trauma. Nevertheless, in patients with low-energy abdominal trauma, the use of CT is debated because of the possible unnecessary radiation exposure. Accordingly, conventional ultrasound (US) imaging has been increasingly employed as the initial imaging modality in the workup of minor traumatic emergency conditions. Focused assessment with sonography for trauma is widely used to detect free intra-abdominal fluid, but its role is controversial, because the absence of free fluid does not exclude the presence of injuries to abdominal organ. Injection of an ultrasound contrast agent (UCA) may give the radiologist relevant additional information to that obtained with conventional US. Thus, in trauma patients, following early assessment with conventional US imaging, a contrast-enhanced US (CEUS) can provide a more reliable evaluation of solid organ injuries and related vascular complications, including active bleeding, pseudoaneurysms, and artero-venous fistulas. CEUS cannot replace abdominal CT, but it represents a noninvasive and repeatable imaging tool capable of providing a reliable assessment of trauma severity and expedite the patient's treatment.

Ultrasound elastography and contrast-enhanced ultrasound in infants, children and adolescents

OBJECTIVE

To describe prerequisites, use, and safety of ultrasound elastography and contrast-enhanced ultrasound in infants, children, and adolescents.

METHOD

This review deals with two latest developments in ultrasonography in children. The principle of strain elastography, transient elastography, and acoustic radiation force imaging is discussed, including limitations, and advantages of the different techniques in diagnosing focal and diffuse organ disease. The intravesical (contrast-enhanced voiding ultrasonography) and intravascular use of contrast-media to outline blood, and urinary flow is described, with special emphasis on indications, off-label use, and diagnostic gain. Examples of indications for performing the advanced ultrasound techniques are presented.

SUMMARY AND CONCLUSION

Latest developments in ultrasound machine engineering, and the availability of contrast-media that interact with ultrasound waves allow for assessment of tissue stiffness/elasticity properties, blood, and urinary flow. Thereby ultrasound is capable not only to depict morphology, but gives the additional information on organ, and focal lesion perfusion, and urinary flow dynamics. The information gap to other cross-sectional techniques such as magnetic resonance imaging, that make potential harmful sedation, and anaesthesia in the youngest children necessary, thereby gets closer.

Nuking the radiation: minimizing radiation exposure in the evaluation of pediatric blunt trauma

PURPOSE OF REVIEW

Our objective is to highlight recent literature investigating low-radiation diagnostic strategies in the evaluation of pediatric trauma.

RECENT FINDINGS

In the area of minor head injury, research has focused on implementation of validated clinical decision rules into practice to reduce unnecessary computed tomography scans. Clinical observation may also serve as an adjunct to initial assessment and a potential substitute for computed tomography imaging. Subgroups of children with special needs or severe injury mechanisms may also be safely characterized by the clinical decision rule and spared radiation exposure. Physical examination techniques may be useful in diagnosing mandibular fractures. In addition, evidence suggests that plain radiography for evaluation of blunt thoracic trauma may be sufficient in many cases, and computed tomography could be reserved for those with abnormal radiographs, high-risk mechanisms, or abnormal physical findings. Clinical decision rules are able to predict intra-abdominal injury with high sensitivity. Data suggest that skeletal surveys may be modified to limit radiation exposure in the case of suspected nonaccidental trauma.

SUMMARY

More research is needed in development of pediatric-specific clinical decision rules and risk stratification and in testing low-radiation diagnostic modalities in the pediatric trauma population.