Blunt abdominal trauma: emergency contrast-enhanced sonography for detection of solid organ injuries

Contrast-enhanced point of care ultrasound for the evaluation of stable blunt abdominal trauma by the emergency physician: A prospective diagnostic study

Objectives

Clinical examination alone cannot reliably rule out significant traumatic abdominal injury. Computed tomography (CT) has become the primary method for evaluating blunt abdominal trauma and clinicians rely heavily on it to rule out abdominal injury. Ultrasound examination may miss significant abdominal injury particularly in stable patients. The use of a contrast agent improves ultrasound sensitivity to visceral abdominal injuries. The objective of this diagnostic study is to compare bedside contrast enhanced ultrasound (CEUS) performed by emergency physicians to CT in hemodynamically stable adults for the assessment of blunt abdominal trauma and evaluate CEUS accuracy outcomes.

Methods

Hemodynamically stable patients with blunt trauma were prospectively enrolled in the trauma bay. After initial evaluation, we included patients at risk of abdominal injury and for whom an abdominal CT was planned by the trauma leader. Ultrasonography was performed prospectively and at the bedside by the emergency physician followed by abdominal CT used as a reference standard.

Results

Thirty-three patients were enrolled in the study; among them, 52% showed positive traumatic findings in abdominal CT scans, and 42% were diagnosed with solid organ lesions. Compared to CT, a focused abdominal sonography (FOCUS) examination, looking for free fluid or perirenal hematoma, showed limited performance for traumatic findings with a sensitivity of 65% (95% confidence interval [CI]: 38%-86%), a specificity of 75% (95% CI: 48%-93%), a negative likelihood ratio (NLR) of 0.47 (95% CI: 0.23-0.95), and a positive likelihood ratio (PLR) of 2.59 (95% CI: 1.03-6.48). When combining FOCUS with CEUS, the sensitivity of the sonography increased to 94% (95% CI: 71%-100%) with a specificity of 75% (95% CI: 48%-93%). The PLR was 3.76 (95% CI: 1.6-8.87) and the NLR was 0.08 (95% CI: 0.01-0.54). In our population, abdominal sonography with contrast failed to identify a single positive abdominal CT with a grade 1 kidney injury.

Conclusions

A FOCUS examination shows limited sensitivity and specificity to detect positive abdominal CT in stable adults with abdominal trauma. With the addition of contrast and careful inspection of solid organs, abdominal sonography with contrast performed by the emergency physician improves the ability to rule out traumatic findings on abdominal CT. CEUS performed by emergency physicians may miss injuries, especially in the absence of free fluid, in cases of low-grade injuries, simultaneous injuries, or poor-quality examinations.

Spread and feasibility of non-operative management (NOM) of traumatic splenic injuries in adults: a national survey

In hemodynamically stable adults sustaining a splenic trauma, non-operative management (NOM) represents the standard approach even in high-severity injuries. However, knowledge, structural, and logistic limitations still reduce its wider diffusion. This study aims to identify such issues to promote the safe and effective management of these injuries.A survey was developed using the SurveyMonkey® software and spread nationally in Italy. The survey was structured into: (1) Knowledge of classification systems; (2) Availability to refer patients; (3) Patients monitoring and follow-up; (4) Center-related.The survey was filled in by 327 surgeons, with a completeness rate of 63%. Three responders out of four are used to manage trauma patients. Despite most responders knowing the existing classifications, their use is still limited in daily practice. If a patient needs to be centralized, the concern about possible clinical deterioration represent the main obstacle to achieving a NOM. The lack of protocols does not allow standardization of patient surveillance according to the degree of injury. The imaging follow-up is not standardized as well, varying between computed tomography, ultrasound, and contrast-enhanced ultrasound.The classification systems need to be spread to all the trauma-dedicated physicians, to speak a common language. A more rational centralization of patients should be promoted, ideally through agreements between peripheral and reference centers, both at regional and local level. Standardized protocols need to be shared nationally, as well as the clinical and imaging follow-up criteria should be adapted to the local features.

The value of contrast-enhanced ultrasound in vascular injury from blunt abdominal trauma in solid organs: Comparison with multidetector computed tomography using angiography as the reference standard

To evaluate the accuracy of contrast-enhanced ultrasound (CEUS) for assessing vascular injury from blunt abdominal trauma in solid organs using angiography as the reference standard and to compare it with contrast-enhanced multidetector computed tomography (MDCT). Forty-nine patients with 52 blunt abdominal trauma lesions who underwent CEUS, MDCT, and angiography were enrolled in this retrospective study. Injuries included the liver (n = 23), kidney (n = 10), and spleen (n = 19). Vascular injury in solid organs was classified into 3 types: isolated pseudoaneurysm, pseudoaneurysm with low-velocity extravasation, and active bleeding. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CEUS and MDCT for the detection and classification of vascular injury in solid organs were calculated based on angiography. The receiver operating characteristic curve analysis of each test was performed and compared. Thirty-nine vascular injuries in solid organs were detected and classified into 9 isolated pseudoaneurysms, 9 pseudoaneurysms with low-velocity extravasation, and 21 active bleeding based on angiography as the reference standard. The sensitivity, specificity, PPV, NPV, and accuracy for bleeding detection were 97.44%, 100.00%, 100.00%, 92.86%, and 98.08%, respectively, for CEUS and MDCT. The sensitivity, specificity, PPV, NPV, and accuracy of classification (isolated pseudoaneurysm vs. pseudoaneurysm with low-velocity extravasation or active bleeding) of bleeding were 96.67%, 87.50%, 96.67%, 87.50%, and 94.74%, respectively, for CEUS and 100.00%, 75.00%, 93.75%, 100.00%, and 94.74%, respectively, for MDCT. The area under the receiver operating characteristic curves of CEUS and MDCT for bleeding detection was 0.987, and the area under the receiver operating characteristic curves for CEUS and MDCT bleeding classification were 0.921 and 0.875, respectively. CEUS and MDCT exhibited comparable consistency with angiography for detecting and classifying vascular injury from blunt abdominal trauma in solid organs. Therefore, CEUS may be an accurate and rapid imaging tool to detect bleeding and determine the need for transcatheter arterial embolization. We suggest that CEUS could be considered a first-line approach during the preparation time before MDCT to determine the appropriate management for blunt abdominal trauma.

Is it time to re-think FAST? A systematic review and meta-analysis of Contrast-Enhanced Ultrasound (CEUS) and conventional ultrasound for initial assessment of abdominal trauma

BACKGROUND

The Focused Assessment with Sonography for Trauma (FAST) examination using conventional ultrasound has limited utility for detecting solid organ injury. Therefore, this systematic review and meta-analysis compares the performance of contrast-enhanced ultrasound (CEUS) to conventional ultrasound when used as the initial assessment for abdominal trauma prior to computed tomography (CT) imaging.

METHODS

A systematic literature search of major databases was conducted of human studies investigating the diagnostic accuracy of conventional ultrasound and CEUS occurring prior to CT imaging for abdominal trauma. The study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. The quality of studies was evaluated using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool. Paired pooled sensitivity and specificity between conventional ultrasound and CEUS were compared using data extracted from the eligible studies. Diagnostic odds ratio, number needed to diagnose values, and likelihood ratios were also determined.

RESULTS

Ten studies were included. More than half of the included studies demonstrated low risk of bias. Using McNemar's test to assess for paired binary observations, we found that CEUS had statistically higher sensitivity (0.933 vs. 0.559; two-tailed, P < 0.001) and specificity (0.995 vs. 0.979; two-tailed, P < 0.001) than conventional ultrasound in the setting of abdominal trauma, respectively. When divided into particular findings of clinical interest, CEUS had statistically higher sensitivity than conventional ultrasound in screening for active bleeding and injuries to all abdominal solid organs. CEUS also had superior diagnostic odds ratios, number needed to diagnose values, and likelihood ratios than conventional ultrasound.

CONCLUSION

The diagnostic value of CEUS was higher than that of conventional ultrasound for differentiating traumatic abdominal injuries when used as the initial assessment in the emergency department.

Contrast-enhanced ultrasonography (CEUS) reveals active bleeding into an abdominal hematoma in a patient with ongoing subcutaneous injections

A 95-year-old woman with metastasizing bronchial carcinoma presents with left inguinal pain. The referring physician would like to exclude an inguinal hernia and a deep vein thrombosis due to her precondition of essential thrombocythemia. Conventional ultrasound excluded the presence of a deep vein thrombosis yet showed a 6 cm × 5 cm hematoma distal of the left m. rectus abdominis. The subsequently performed color Doppler examination excluded a pseudoaneurysm but could not preclude active bleeding. Eventually, CEUS showed contrast-pooling within the hematoma as a sign of active extravasation, suggesting ongoing bleeding.

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.

Role of Contrast-Enhanced Ultrasound (CEUS) in Native Kidney Pathology: Limits and Fields of Action

Gray scale ultrasound has an important diagnostic role in native kidney disease. Low cost, absence of ionizing radiation and nephrotoxicity, short performance time, and repeatability even at the bedside, are the major advantages of this technique. The introduction of contrast enhancement ultrasound (CEUS) in daily clinical practice has significantly reduced the use of contrast enhancement computed tomography (CECT) and contrast enhancement magnetic resonance (CEMR), especially in patients with renal disease. Although there are many situations in which CECT and CEMRI are primarily indicated, their use may be limited by the administration of the contrast medium, which may involve a risk of renal function impairment, especially in the elderly, and in patients with acute kidney injury (AKI) and moderate to severe chronic kidney disease (CKD). In these cases, CEUS can be a valid diagnostic choice. To date, numerous publications have highlighted the role of CEUS in the study of parenchymal micro-vascularization and renal pathology by full integration with second level imaging methods (CECT and CEMRI) both in patients with normal renal function and with diseased kidneys. The aim of this review is to offer an updated overview of the limitations and potential applications of CEUS in native kidney disease.

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.

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.

Does contrast-enhanced ultrasound have a role in evaluation and management of pediatric renal trauma? A preliminary experience

BACKGROUND

To report our initial experience using intravenous contrast-enhanced ultrasound (CEUS) in pediatric renal trauma with the potential for substantial radiation reduction.

METHODS

A retrospective review of all patients who underwent intravenous CEUS at our institution between May 2015 and January 2018 for the suspicion of blunt renal trauma. CEUS was obtained either as an immediate or short-term comparison to contrast-enhanced computed tomography (CECT), or in outpatient follow-up.

RESULTS

CEUS was performed on 7 patients (9 kidneys) with age range 2 months to 16 years old. CEUS was utilized as a comparison to CECT in 4 of 7 patients for initial evaluation, clinical change, or short-term follow-up. CEUS alone was used in one patient with low suspicion for renal injury. In the remaining two patients, CEUS was obtained as a follow-up study weeks after the initial CECT, following conservative management. All patients with confirmed renal injury by CECT (n = 5) underwent a follow-up CEUS at 1-2 months.

CONCLUSIONS

In an era of conservative management for renal trauma in which operative intervention is dictated more often by the clinical course than radiographic findings, it is reasonable to consider alternative imaging methods such as CEUS in stable patients to decrease radiation exposure.

LEVEL OF EVIDENCE RATING

IV.

The role of multiparametric ultrasound in the diagnosis of paediatric scrotal pathology

Multiparametric ultrasound (MPUS), combining conventional techniques (greyscale and colour Doppler ultrasound), ultrasound strain elastography, and contrast-enhanced ultrasound (CEUS), has been successfully used in the assessment of adult scrotal pathology. Contrast-enhanced ultrasound can confidently establish testicular tissue vascularity even in the small-volume paediatric testis. Elastography provides further assessment of tissue stiffness, potentially adding useful diagnostic information. In children, ultrasonography is particularly advantageous, being safe, radiation-free and negating the need for sedation or general anaesthesia during the imaging evaluation. In this review article, we aim to familiarise readers with the MPUS scanning protocol used for paediatric scrotal examination and provide an overview of scrotal MPUS features, with particular focus to clinical indications where MPUS may be advantageous over conventional ultrasonography.

Application of Contrast-Enhanced Real-time 3-Dimensional Ultrasound in Solid Abdominal Organ Trauma

OBJECTIVES

To determine whether real-time 3-dimensional ultrasound (RT3DUS) could provide additional information on early detection and evaluation in the management of solid abdominal organ trauma based on an animal model.

METHODS

Nine bleeding lesions were developed in the livers (n = 3), kidneys (n = 3), and spleens (n = 3) from 9 pigs. An ultrasound contrast agent was administered intravenously (liver, 0.025 mL/kg; kidney, 0.008 mL/kg; and spleen, 0.013 mL/kg) after an unenhanced 2-dimensional ultrasound (2DUS) examination (B-mode and color Doppler). After contrast agent injection, bleeding lesions were imaged by 2DUS and sequentially imaged by 3-dimensional static ultrasound (3DSUS) and RT3DUS to identify active bleeding, observe the relationship between bleeding lesions and peripheral blood vessels, and evaluate the spatial scope of the bleeding lesions in the organs.

RESULTS

For the identification of active bleeding, there was no statistical difference in contrast-enhanced 2DUS, 3DSUS, and RT3DUS. For observation of the relationship between bleeding lesions and peripheral blood vessels, RT3DUS performed statistically better than 2DUS (P < .05), as reconstructed RT3DUS could show more information about the relationship. For the evaluation of the spatial scope of the bleeding lesion in the organ, RT3DUS also performed statistically better than 2DUS from the multiplanar observation by postprocessing of the 3-dimensional real-time volumes (P < .05).

CONCLUSIONS

Real-time 3-dimensional ultrasound improves early detection and evaluation of solid abdominal organ trauma and provides additional information over the current contrast-enhanced 2DUS.

Contrast-enhanced ultrasonography (CEUS) in the follow-up of pediatric abdominal injuries: value and timing

AIMS

Primary aim was to investigate the value and safety of contrast-enhanced ultrasonography (CEUS) during follow-up (FU) of splenic, hepatic and renal post-traumatic injuries in a pediatric population. Secondary aim was to extrapolate appropriate timing of FU-CEUS.

METHODS

In a retrospective study, post-traumatic parenchymal injuries diagnosed with CT or CEUS, were subjected to non-operative management and followed with CEUS.

RESULTS

Forty-six patients were enrolled, with isolated or combined injuries, for a total of 30 splenic, 15 hepatic and 12 renal injuries. At admission 42/46 patients underwent CT and 4/46 underwent CEUS. During FU a total of 65 CEUS were performed: 16 within 72 h to check delayed active bleeding or parenchymal rupture; 24 between 5 and 10 days post admission, to pose indication to active mobilization or to discharge; 21 between 20 and 60 days post admission to document complete healing of the lesion or pose indication to discharge in most severe injuries. No complications related to CEUS were encountered.

CONCLUSIONS

CEUS is valuable and safe to follow patients with post-traumatic abdominal injuries, even if further data are needed for renal injuries. We propose a tailored approach based on injury grade and clinical course: in the first 3 days only in case of delayed bleeding or rupture suspect; between 5 and 10 days post trauma to ensure a safe active mobilization and/or pose indication to discharge, and over 20-30 days post trauma to pose indication to discharge in most severe injuries or document complete healing and permit return to sport activities.

Interventional Ultrasound Assisted Early Local Hemostatic Drug Therapy in Traumatic Intracerebral Hemorrhage

This article aims to test a minimally invasive interventional approach by real-time transcranial contrast-enhanced ultrasound (CEUS) through a small bur hole to achieve an early local hemostatic drug therapy in a novel traumatic intracerebral hematoma (ICH) model of pigs with hemostatic abnormalities. The effects of hemostasis in the hemocoagulase atrox (HA) injection group and saline injection group groups were observed by transcranial CEUS at three time points: 0 s, 10 s, 2nd. We successfully established a novel traumatic ICH model of pigs with hemostatic abnormalities by the methods of interventional ultrasound techniques and observed the effect of hemostasis by using HA in a local injection method with the assistance of minimally invasive interventional ultrasound technique. At 0 s, four pigs (100%) were observed that active bleeding was significantly weakened, and the range of hematoma became smaller in the HA group. At 10 s, four pigs (100%) were observed that active bleeding became much weaker, and the range of hematoma became further smaller in the HA group. At 2nd, zero pigs (0/4, 0%) were observed that active bleeding could be clearly identified and four pigs (100%) with ICH could also be observed in the HA group. We believe this useful technique could minimize the invasiveness and be operated at the bedside, which would bring much more benefits for traumatic ICH patients.

Demonstration of Improved Renal Congestion After Heart Failure Treatment on Renal Perfusion Imaging With Contrast-Enhanced Ultrasonography

Background: Renal congestion is a critical pathophysiological component of congestive heart failure (CHF). Methods and Results: To quantify renal congestion, contrast-enhanced ultrasonography (CEUS) was performed at baseline and after treatment in 11 CHF patients and 9 normal subjects. Based on the time-contrast intensity curve, time to peak intensity (TTP), which reflects the perfusion rate of renal parenchyma, and relative contrast intensity (RCI), an index reflecting renal blood volume, were measured. In CHF patients, TTP at baseline was significantly prolonged compared with that in controls (cortex, 10.8±3.5 vs. 4.6±1.2 s, P<0.0001; medulla, 10.6±3.0 vs. 5.1±1.6 s, P<0.0001), and RCI was lower than that in controls (cortex, -16.5±5.2 vs. -8.8±1.5 dB, P<0.0001; medulla, -22.8±5.2 vs. -14.8±2.4 dB, P<0.0001). After CHF treatment, RCI was significantly increased (cortex, -16.5±5.2 to -11.8±4.5 dB, P=0.035; medulla, -22.8±5.2 to -18.7±3.7 dB, P=0.045). TTP in the cortex decreased after treatment (10.8±3.5 to 7.6±3.1 s, P=0.032), but it was unchanged in the medulla (10.6±3.0 to 8.3±3.2 s, P=0.098). Conclusions: Renal congestion can be observed using CEUS in CHF patients.

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.

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.

Diagnosis of congenital and acquired focal lesions in the neck, abdomen, and pelvis with contrast-enhanced ultrasound: a pictorial essay

Contrast-enhanced ultrasound (CEUS) is a versatile imaging modality that improves the diagnostic potential of conventional ultrasound. It allows for portable imaging at the bedside. In this paper, we illustrate how CEUS can be used in evaluating several focal lesions in the pediatric population, including liver hemangioma, telangiectasias, splenic hamartomas, and bladder lesions. We describe the ultrasound findings and contrast enhancement patterns associated with these lesions. Findings are correlated with MRI, CT, and/or pathology when available. This paper demonstrates the value of CEUS in improving characterization of many focal lesions in the pediatric population.

CONCLUSION

CEUS is a valuable bedside technique for use in the pediatric population to evaluate focal lesions in various organs, and will allow for safe, more efficient diagnostic imaging. What is Known: • CEUS offers many advantages over CT and MRI and is underutilized in the United States. • It is only FDA approved for vesicoureteral reflux and liver in the pediatric population. However, off label uses are well described. What is New: • This pictorial essay describes ultrasound findings and contrast enhancement patterns associated with liver hemangioma, liver telangiectasia, splenic hamartoma, hemorrhagic ovarian cyst, urachal remnant, spinning top urethras, and kaposiform hemangioendothelioma. • We demonstrate the utility of CEUS in expanding the diagnostic potential of conventional ultrasound.

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.

Pancreaticobiliary Trauma: A Multimodality Imaging Update

Pancreaticobiliary injury is an uncommon entity which more often occurs in the setting of blunt than penetrating trauma. We present cases of pancreaticobiliary traumatic injuries from our Level 1 trauma center to illustrate an imaging update on the spectrum of injuries and correlation with current grading systems.

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.

Blunt Abdominal Trauma with Left Kidney Dropped into Lower Retroperitoneal Cavity: A Case Report and Literature Review

Blunt abdominal injury with kidney laceration is not unusually seen in high-energy traffic accident. It can present with no symptoms and yet lead to fatal complications. High-grade lacerations of kidney (American Association for the Surgery of Trauma [AAST] grade IV to V) will show up with contrast extravasation and disrupted kidney/pelvicalyceal system morphology in computed tomography (CT). However, it is rare to see kidney dislocation from retroperitoneal space because of the presence of the Gerota's fascia. We present a case of a 16-year-old boy suffering from traffic accident with blunt truncal/abdominal injury. The contrast CT of abdomen revealed that his left kidney was dislocated from the original retroperitoneal space and sagged to the lower retroperitoneal cavity. We performed emergency left nephrectomy. He recovered well and there was no complication noted after the surgical intervention. We also review the literature of kidney laceration regarding diagnosis and treatment. (Hong Kong j.emerg.med. 2016;24:176-179)

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.

Effectiveness of contrast-enhanced ultrasound and serum liver enzyme measurement in detection and classification of blunt liver trauma

Objective

This study was performed to identify the correlation between contrast-enhanced ultrasound (CEUS) and contrast-enhanced multidetector computed tomography (CE-MDCT) as well as the correlation between serum liver enzyme concentrations and CE-MDCT in classification of the severity of blunt hepatic trauma using CE-MDCT as a reference standard.

Materials and methods

A blunt liver trauma model was created using 20 rabbits, and CE-MDCT, CEUS, and serum liver enzyme assays were performed. A radiologist and an ultrasound physician independently evaluated the degree of liver trauma. The diagnostic performance of CEUS and serum liver enzyme measurements was compared with that of CE-MDCT using Spearman’s correlation analysis and Pearson’s correlation analysis, respectively.

Results

Spearman’s rank correlation coefficient between the CEUS-based classification and CE-MDCT was 0.888. The aspartate aminotransferase and lactate dehydrogenase concentrations and the aspartate aminotransferase/alanine aminotransferase ratio were positively correlated with the grade of liver injury; Pearson’s correlation coefficients were 0.664, 0.704, and 0.503, respectively. The gamma-glutamyltransferase concentration had a significantly negative correlation with the grade of liver injury (r = −0.467).

Conclusions

CEUS and serum liver enzyme measurement exhibited high consistency with CE-MDCT for both detection and grading of intraparenchymal lesions in blunt liver trauma. These techniques may permit more accurate diagnosis of liver trauma.

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.

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.

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.

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.

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.

Imaging assessment of renal injuries in children and adolescents: CT or ultrasound?

BACKGROUND

Since the introduction of the ALARA ("as low as reasonably achievable") concept, ultrasound (US) has been progressively advocated for paediatric diagnostic imaging. This study aimed to analyse the role and accuracy of US in paediatric renal trauma.

METHODS

From 1999 to 2009, the tertiary-care-hospital database was retrospectively evaluated for renal trauma with regards to aetiology, type of injury, diagnostics, management and outcome.

RESULTS

Forty-seven patients (29 males, 18 females; median age=14years, range 1-17 years) were identified. US was initially applied in 45 patients with correct results in 86.6%. Computed tomography (CT) was performed in 16 patients in the acute trauma setting - complementary to US in 14 cases, with a diagnostic accuracy of 93%. Most renal injuries were grade I° (n=30), followed by grade III° (n=8), IV° (n=5), and II°/V° (n=2 each). All patients were initially managed conservatively and followed by US. Clinical deterioration necessitated surgery in four patients (2 nephrectomies, 1 partial nephrectomy, 1 urinoma drainage). The outcome was generally favourable with a renal preservation rate of 95%.

CONCLUSION

With respect to the ALARA principle, US can be safely and reliably applied as the first-line diagnostic imaging technique and for follow-up for suspected traumatic paediatric renal injuries.

Contrast-enhanced ultrasound (CEUS) in nephrology: Has the time come for its widespread use?

Grey-scale ultrasound has an important diagnostic role in nephrology. The absence of ionizing radiations and nephrotoxicity, rapidity of execution, excellent repeatability, the possibility to perform the test at the patient's bed and the low cost represent important advantages of this technique. Paired with real-time sonography and colour-power-Doppler contrast-enhanced ultrasound (CEUS) reduces the diagnostic gap with computed tomography (CT) and magnetic resonance (MR) and represents a major step in the evolution of clinical ultrasound. Although there are several situations in which contrast-enhanced CT and MR are indicated (i.e. evaluation of cystic or ischemic lesions, traumatisms and ablative therapies of the native and transplanted kidney), the use of CT contrast media presents a high risk of contrast-induced nephropathy (i.e. in elderly people, subjects with comorbidities and those with renal dysfunction), while gadolinium-based RM contrast agents are contraindicated for the risk of nephrogenic systemic fibrosis (i.e. in patients with severe renal dysfunction). In these situations, CEUS may be a viable alternative, however, as any technique associated with the infusion of pharmacological substances, the potential advantages and risks of CEUS should be critically evaluated. In this regard, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) has published the guidelines for the use of CEUS for the kidney imaging and the International Contrast Ultrasound Society (ICUS) has been recently founded. The aim of this review is to offer an updated overview of the potential applications of CEUS in nephrology, reporting some indications and possible risks associated to its use.

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.

Effectiveness of contrast-enhanced ultrasound in the classification and emergency management of abdominal trauma

OBJECTIVE

To analyse the correlation between contrast-enhanced ultrasound (CEUS)-based classification of the severity of abdominal parenchymal organ trauma and clinical outcomes, and to explore CEUS in classifying patients with such trauma, expecting that the use of CEUS will potentially enhance the quality and speed of the emergency management of abdominal trauma.

METHODS

Three hundred six consecutive patients with blunt abdominal parenchymal organ trauma who received CEUS examination were retrospectively analysed. Two CEUS radiologists (identified as Reader A and Reader B in this study) who were not involved in the CEUS examinations of the patients were then asked to classify the patients independently according to their CEUS results. The classification results were later compared with patients' clinical outcomes using Spearman's rank correlation.

RESULTS

The final clinical outcomes showed that 25.5 % (78/306) of patients received conservative treatment, 52.0 % (159/306) received minimally invasive treatment, and 22.5 % (69/306) received surgery. Spearman's rank correlation coefficients between the CEUS-based classification and clinical outcome were 0.952 from Reader A and 0.960 from Reader B.

CONCLUSIONS

CEUS can play an important role in the emergency management of abdominal trauma through the classification of patients for different treatment methods.

KEY POINTS

• The severity of abdominal trauma was classified by contrast-enhanced ultrasound (CEUS) • There was a high correlation between CEUS-based classification and clinical outcomes • CEUS-based classification is helpful for surgeons in the emergency management of abdominal trauma.

Blunt abdominal trauma: role of contrast-enhanced ultrasound (CEUS) in the detection and staging of abdominal traumatic lesions compared to US and CE-MDCT

PURPOSE

This study was undertaken to evaluate the accuracy of contrast-enhanced ultrasound (CEUS) in the detection and grading of abdominal traumatic lesions in patients with low-energy isolated abdominal trauma in comparison with baseline ultrasound (US) and contrast-enhanced multidetector computed tomography (CE-MDCT), considered the gold standard.

MATERIALS AND METHODS

A total of 256 consecutive patients who arrived in our Emergency Department between January 2006 and December 2012 (159 males and 97 females aged 7-82 years; mean age 41 years), with a history of low-energy isolated abdominal trauma were retrospectively analysed. All patients underwent US, CEUS with the use of a second-generation contrast agent (Sonovue, Bracco, Milan, Italy) and MDCT. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) and overall accuracy for the detection of lesions and free peritoneal fluid on US and CEUS, and sensitivity for the grading of lesions on CEUS were calculated compared with the CT findings, in accordance with the American Association for the Surgery of Trauma criteria.

RESULTS

CE-MDCT identified 84 abdominal traumatic lesions (liver = 28, spleen = 35, kidney = 21) and 45 cases of free intraperitoneal fluid. US depicted 50/84 traumatic lesions and 41/45 cases of free peritoneal fluid; CEUS identified 81/84 traumatic lesions and 41/45 free peritoneal fluid. The sensitivity, specificity, PPV, NPV and overall accuracy for the identification of traumatic abdominal lesions were 59, 99, 98, 83 and 86 %, respectively, for US and 96, 99, 98, 98 and 98 %, respectively, for CEUS. The values for the identification of haemoperitoneum were 91, 99, 95, 98 and 97 %, respectively, for US and 95, 99, 95, 99 and 98 %, respectively, for CEUS. CEUS successfully staged 72/81 traumatic lesions with a sensitivity of 88 %.

CONCLUSIONS

In patients with low-energy isolated abdominal trauma US should be replaced by CEUS as the first-line approach, as it shows a high sensitivity both in lesion detection and grading. CE-MDCT must always be performed in CEUS-positive patients to exclude active bleeding and urinomas.

Emergency contrast-enhanced ultrasonography for pancreatic injuries in blunt abdominal trauma

PURPOSE

The purpose of this study was to retrospectively investigate the application of emergency contrast-enhanced ultrasonography (CEUS) in blunt pancreatic trauma.

MATERIALS AND METHODS

Twenty-two consecutive patients with blunt pancreatic trauma were examined using CEUS from March 2007 to June 2012. The findings of CEUS were compared with those of contrast-enhanced computed tomography scans at level-1 diagnostic tests.

RESULTS

Out of the 22 patients, 21 were diagnosed with blunt pancreatic injury using CEUS, including 8 patients with lesions in the neck of pancreas, 9 in the body, 3 in the tail and 1 in the head. The injury sites appeared as anechoic and/or hypoechoic perfusion defect regions with irregular borders in parenchyma and capsule on CEUS images. The lesion sizes measured by CEUS were 1.88 ± 0.81 cm, which were consistent with the 1.93 ± 0.77 cm measured by CT (p > 0.05). Using CT as a reference standard, the detection rate of CEUS in blunt pancreatic trauma was 95.5 % (21/22).

CONCLUSIONS

CEUS findings can be used to provide a reliable diagnosis for blunt pancreatic trauma. CEUS is thus promising in the assessment of blunt pancreatic trauma, especially in institutions where emergency CEUS is used as an initial diagnostic instrument.

Characterization of indeterminate spleen lesions in primary CT after blunt abdominal trauma: potential role of MR imaging

The purpose of this study was to determine the value of magnetic resonance imaging (MRI) for characterization of indeterminate spleen lesions in primary computed tomography (CT) of patients with blunt abdominal trauma. Twenty-five consecutive patients (8 female, 17 male, mean age 51.6 ± 22.4 years) with an indeterminate spleen lesion diagnosed at CT after blunt abdominal trauma underwent MRI with T2- and T1-weighted images pre- and post-contrast material administration. MRI studies were reviewed by two radiologists. Age, gender, injury mechanism, injury severity score (ISS), management of patients, time interval between CT and MRI, and length of hospital stay were included into the analysis. Patient history, clinical history, imaging, and 2-month clinical outcome including review of medical records and telephone interviews served as reference standard. From the 25 indeterminate spleen lesions in CT, 11 (44 %) were traumatic; nine (36 %) were non-traumatic (pseudocysts, n=5; hemangioma, n=4) and five proven to represent artifacts in CT. The ISS (P<0.001) and the length of hospital stay (P=0.03) were significantly higher in patients with spleen lesions as compared with those without. All other parameters were similar among groups (all, P>0.05). The MRI features ill-defined lesion borders, variable signal intensity on T1- and T2-weighted images depending on the age of the hematoma, focal contrast enhancement indicating traumatic pseudoaneurysm, perilesional contrast enhancement, and edema were most indicative for traumatic spleen lesions. As compared with CT (2/25), MRI (5/25) better depicted thin subcapsular hematomas as indicator of traumatic spleen injury. In conclusion, MRI shows value for characterizing indeterminate spleen lesions in primary CT after blunt abdominal trauma.

Contrast-enhanced sonographically guided percutaneous 915-MHz microwave ablation therapy compared to local hemostatic drug injection in a renal artery injury model

OBJECTIVES

The purpose of this study was to show the contrast-enhanced sonographic features of various levels of renal artery rupture and to validate the therapeutic effects of percutaneous 915-MHz microwave ablation compared to hemostatic drug injection (batroxobin) using an in vivo canine renal artery injury model.

METHODS

Three renal artery hemorrhage models (A, diameter <1 mm, subcapsular artery; B, diameter 1-2 mm, interlobar artery; and C, diameter 2-3 mm, segmental artery) were created in 24 canines for this study. Contrast-enhanced sonography was used to show the bleeding features and guide hemostatic therapies using 915-MHz microwave ablation and local batroxobin injection. Success rates were assessed according to amounts of bleeding, times required for hemostatic action, and volumes of fluid infusion required using pathologic examination as a reference standard.

RESULTS

Contrast-enhanced sonography clearly showed renal artery ruptures with active bleeding at various levels and degrees and was very useful to make diagnoses and guide therapies. The success rate in the microwave treatment group was higher than that in the drug injection group (except group A; P< .05). The time required for hemostasis and the volume of fluid infusion required in the microwave group were notably less than those in the drug injection group (P < .05).

CONCLUSIONS

Contrast-enhanced sonography is a useful imaging method for assessing renal vessel injury and guide interventional therapies. Contrast-enhanced sonographically guided percutaneous 915-MHz microwave ablation is a preferred hemostatic technique for treatment of renal artery injury, with greater effectiveness and less tissue damage compared to local drug injection.

Contrast enhanced ultrasound of the kidneys: what is it capable of?

One of the many imaging uses of contrast enhanced ultrasound (CEUS) is studying a wide variety of kidney pathology, due to its ability to detect microvascular blood flow in real time without affecting renal function. CEUS enables dynamic assessment and quantification of microvascularisation up to capillary perfusion. The objective of this paper is to briefly refresh basic knowledge of ultrasound (US) contrast agents' physical properties, to study technical details of CEUS scanning in the kidneys, and to review the commonest renal indications for CEUS, with imaging examples in comparison to baseline unenhanced US and computed tomography when performed. Safety matters and limitations of CEUS of the kidneys are also discussed.