Blunt hepatic trauma: evaluation with contrast-enhanced sonography: sonographic findings and clinical application

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 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.

Contrast-enhanced US for the Interventional Radiologist: Current and Emerging Applications

US is a powerful and nearly ubiquitous tool in the practice of interventional radiology. Use of contrast-enhanced US (CEUS) has gained traction in diagnostic imaging given the recent approval by the U.S. Food and Drug Administration (FDA) of microbubble contrast agents for use in the liver, such as sulfur hexafluoride lipid-type A microspheres. Adoption of CEUS by interventional radiologists can enhance not only procedure guidance but also preprocedure patient evaluation and assessment of treatment response across a wide spectrum of oncologic, vascular, and nonvascular procedures. In addition, the unique physical properties of microbubble contrast agents make them amenable as therapeutic vehicles in themselves, which can lay a foundation for future therapeutic innovations in the field in drug delivery, thrombolysis, and vascular flow augmentation. The purpose of this article is to provide an introduction to and overview of CEUS aimed at the interventional radiologist, highlighting its role before, during, and after frequently practiced oncologic and vascular interventions such as biopsy, ablation, transarterial chemoembolization, detection and control of hemorrhage, evaluation of transjugular intrahepatic portosystemic shunts (TIPS), detection of aortic endograft endoleak, thrombus detection and evaluation, evaluation of vascular malformations, lymphangiography, and percutaneous drain placement. Basic physical principles of CEUS, injection and scanning protocols, and logistics for practice implementation are also discussed. Early adoption of CEUS by the interventional radiology community will ensure rapid innovation of the field and development of future novel procedures. Online supplemental material is available for this article. ^©RSNA, 2020.

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.

Follow-Up Imaging in Patients with Blunt Splenic or Hepatic Injury Managed Nonoperatively

Nonoperative management of blunt splenic and hepatic injuries has become the standard of care for hemodynamically stable patients. However, nonoperative management may lead to delayed complications and appropriate follow-up is therefore crucial. The aim of this systematic literature review was to assess the role of different imaging modalities in the follow-up assessment of patients with blunt splenic or hepatic injuries using the PubMed database. Eighteen studies were found to be relevant to the topic. A total of 2725 patients were enrolled in the included studies. Both retrospective and prospective studies, but no randomized controlled trials were found. In these studies, CT, ultrasound, and contrast-enhanced ultrasound were discussed. CT was the most commonly used imaging modality. Taking into account all studies included, only one patient underwent intervention due to a complication diagnosed by follow-up CTscan in the absence of clinical signs and symptoms. This equates to a total of 920 CT scans performed to diagnose one clinically nonevident complication that required intervention. Based on the reviewed literature, routine imaging follow-up CT scans may not be indicated in asymptomatic patients with lower grade blunt splenic or hepatic injuries. Contrast-enhanced ultrasound is a promising alternative imaging modality for the follow-up of these patients.

Contrast-Enhanced Ultrasound of the Liver: Optimizing Technique and Clinical Applications

OBJECTIVE

The purpose of this article is to review the general principles, technique, and clinical applications of contrast-enhanced ultrasound of the liver.

CONCLUSION

Proper technique and optimization of contrast-enhanced ultrasound require a balance between maintaining the integrity of the microbubble contrast agent and preserving the ultrasound signal. Established and emerging applications in the liver include diagnosis of focal lesions, aiding ultrasound-guided intervention, monitoring of therapy, and aiding surgical management.

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.

Contrast enhanced ultrasound (CEUS) in blunt abdominal trauma

In the assessment of polytrauma patient, an accurate diagnostic study protocol with high sensitivity and specificity is necessary. Computed Tomography (CT) is the standard reference in the emergency for evaluating the patients with abdominal trauma. Ultrasonography (US) has a high sensitivity in detecting free fluid in the peritoneum, but it does not show as much sensitivity for traumatic parenchymal lesions. The use of Contrast-Enhanced Ultrasound (CEUS) improves the accuracy of the method in the diagnosis and assessment of the extent of parenchymal lesions. Although the CEUS is not feasible as a method of first level in the diagnosis and management of the polytrauma patient, it can be used in the follow-up of traumatic injuries of abdominal parenchymal organs (liver, spleen and kidneys), especially in young people or children.

A novel hemostatic sealant composed of gelatin, transglutaminase and thrombin effectively controls liver trauma-induced bleeding in dogs

AIM

novel hemostatic sealant based on the in situ gel formation of gelatin catalyzed by thrombin and crosslinked by transglutaminase was designed. The aim of this study was to investigate the efficacy of the hemostatic sealant in control of bleeding caused by liver trauma in dogs.

METHODS

Hepatic trauma that mimicked the grade III-IV rupture of liver was made in 20 dogs. The traumatic lesion was topically administered the hemostatic sealant (treatment group, n=10), or a thrombin solution (control group, n=10). The time to achieve hemostasis and the blood loss were measured. Contrast-enhanced ultrasound (CEUS) examination was performed in each animal on d 3, d 7, and d 10 d postoperatively to study the healing of the lesions.

RESULTS

The mean time to achieve hemostasis in the treatment group was significantly shorter than that in the control group (1.20±0.33 vs 6.70±0.64 min, P<0.05). The mean blood loss in the treatment group was significantly less than that in the control group (47.22±8.61 vs 79.29±11.97 mL, P<0.05). In CEUS examination, the traumatic lesions in the treatment group became significantly smaller on d 3, and disappeared on d 7, whereas the lesions in the control group still existed on d 10. Ascites were never found during 10 d follow-up in the treatment group but were observed on d 3 and d 7 in the control group.

CONCLUSION

Compared with thrombin, the novel hemostatic sealant shows much better efficacy in hemostasis and may promote wound healing in dog liver trauma.

Percutaneous radiofrequency ablation guided by contrast-enhanced ultrasound in treatment of metastatic hepatocellular carcinoma after liver transplantation

This study evaluated the advantages and applications of contrast-enhanced ultrasound (CEUS)-supported percutaneous radiofrequency ablation (RFA) in the treatment of metastatic hepatocellular carcinoma after liver transplantation, based on clinical details. CEUS-supported percutaneous RFA was adopted to treat 12 patients with hepatic metastatic carcinomas after liver transplantation. The diameters of the metastatic carcinomas varied from 1 cm to 5 cm, and the foci were discovered after 3 months to 12 months. Each focus was diagnosed and localised by CEUS for RFA once or twice. Curative effects were evaluated by CEUS or contrast-enhanced CT after the treatment. The re-examination results at 2 weeks post-treatment showed that the foci of 11 patients were ablated completely, whereas one patient with the largest focus required retreatment by RFA because of a partial residue. No local recurrence was found one month later in the re-examination. CEUS-supported percutaneous RFA in the treatment of hepatic metastatic carcinoma after liver transplantation has the advantages of accurate localisation, good efficacy, easy operation, and minimal invasion without any complications. Therefore, it can be recommended as the preferred therapy for hepatic metastatic carcinoma after liver transplantation.

Evaluation of blunt pancreatic injury with contrast-enhanced ultrasonography in comparison with contrast-enhanced computed tomography

The aim of the present study was to evaluate acute blunt pancreatic injury using contrast-enhanced ultrasonography (CEUS) in comparison with contrast-enhanced computed tomography (CECT). Superficial and deep lesions were established by blunt pancreatic injury in 40 Chinese Guangxi Bama miniature pigs. Conventional ultrasound (US), CEUS and CECT were performed to detect traumatic lesions in the pancreas. A total of 40 lesions were established, including 20 deep lesions and 20 superficial lesions. US identified 21 of the 40 lesions, including 7 of the 20 superficial and 14 of the 20 deep lesions. CEUS identified 34 of the 40 lesions, including 14 of the 20 superficial and 20 of the 20 deep lesions. CECT identified 33 of the 40 lesions, including 13 of the 20 superficial and 20 of the 20 deep lesions. The detection rate of acute blunt pancreatic injury using CEUS was significantly higher compared with that using US (85 vs. 52.5%, P<0.05), however there was no significant difference in the detection rate of pancreatic lesions between CEUS and CECT (85 vs. 82.5%, P>0.05). CEUS improves the diagnostic levels of conventional US and is comparable with CECT scans in the diagnosis of blunt pancreatic injury.

The use of contrast-enhanced ultrasound for the evaluation of solid abdominal organ injury in patients with blunt abdominal trauma

BACKGROUND

The evaluation and management of blunt abdominal trauma is primarily nonoperative. Previous attempts to identify parenchymal solid-organ injury with sonography have been unsatisfactory. The use of Perflutren Lipid Microsphere (Definity) contrast-enhanced ultrasound (DUS) may provide an additional modality for evaluation of solid-organ injury with decreased risk of radiation exposure and contrast-related complications.

METHODS

Injured patients admitted to a state-designated Level I trauma center (January 2008 to July 2009), who showed evidence of solid-organ injury after blunt abdominal trauma on initial computed tomography (CT) were eligible for entry into the study. Patients underwent DUS examinations within 12 hours of initial CT. Ultrasound images were then compared with findings of CT for organ location, size, and grade of injury.

RESULTS

Twenty patients with evidence of solid-organ injury on CT were evaluated with DUS. DUS correctly identified five of eight liver lesions, with a sensitivity of 62.5%. DUS correctly identified all nine splenic lesions demonstrating a sensitivity of 100%. DUS correctly identified one of two kidney injuries, demonstrating a sensitivity of 50%. Overall, the positive predictive value for all solid-organ injuries was 100%, with negative predictive value of 20%. The overall sensitivity for DUS was 79% (15 of 19 patients), and specificity was 100% (15 of 15 patients).

CONCLUSION

Contrast-enhanced sonography is a potential new modality for the evaluation of solid-organ injury for patients with blunt abdominal trauma. With further research, DUS may provide a safe and accurate alternative to CT.

LEVEL OF EVIDENCE

Diagnostic study, level IV.

Massive Liver Trauma-Multidisciplinary Approach and Minimal Invasive Surgery can Salvage Patients

Management of massive liver trauma (grades IV-VI) is associated with high morbidity and mortality. It can pose serious challenges to treating physician and requires multimodality interventions. For a successful outcome, timing of intervention is crucial. We report a case of grade V hepatic injury treated successfully with angioembolization, laparoscopic lavage, and endoscopic stenting during a time period from admission to discharge on the 24th day. Angioembolization was performed at admission after resuscitation as CT scan showed active extravasation in the arterial phase. Laparoscopic lavage and drainage was performed on the fifth day as abdominal inflammatory response failed to respond to medical management. There was biliary component of abdominal fluid noticed during laparoscopy, which manifested by postoperative localized biliary fistula; hence endoscopic stenting of the bile duct was performed on the seventh day. The patient recovered well with timely minimal invasive approach and was fine at 1 year follow-up.

Targeted microbubbles in the experimental and clinical setting

BACKGROUND

Microbubbles have improved ultrasonography imaging techniques over the past 2 decades. Their safety, versatility, and easiness of use have rendered them equal or even superior in some instances to other imaging modalities such as computed tomography and magnetic resonance imaging. Herein, we conducted a literature review to present their types, general behavior in tissues, and current and potential use in clinical practice.

METHODS

A literature search was conducted for all preclinical and clinical studies involving microbubbles and ultrasonography.

RESULTS

Different types of microbubbles are available. These generally improve the enhancement of tissues during ultrasonography imaging. They also can be attached to ligands for the target of several conditions such as inflammation, angiogenesis, thrombosis, apoptosis, and might have the potential of carrying toxic drugs to diseased sites, thereby limiting the systemic adverse effects.

CONCLUSIONS

The use of microbubbles is evolving rapidly and can have a significant impact on the management of various conditions. The potential for their use as targeting agents and gene and drug delivery vehicles looks promising.

Evaluation and establishment of a canine model of delayed splenic rupture using contrast-enhanced ultrasound

The aim of the present study was to establish a canine model of delayed splenic rupture (DSR). A total of 15 mongrel dogs were anesthetized and laparotomized. The hematomas were observed following an injection of heparin. The hematomas were ruptured. The severity of the spleen rupture was evaluated and the intra-abdominal free liquid was measured. The splenic hematomas in the dogs continued to form and the hematoma area gradually increased. The hematomas were ruptured after impacting the abdominal wall. The spleens were damaged, and conventional ultrasonography showed intra-abdominal free liquid. These conditions were demonstrated via computed tomography scanning. A DSR canine model was established successfully.

Contrast-enhanced sonography in blunt scrotal trauma()

The scope of this study was to determine whether contrast-enhanced ultrasonography (CEUS), compared with basic US, can increase diagnostic confidence and provide relevant information on blunt scrotal trauma. Over a period of 75 months we examined 40 patients seen consecutively for blunt scrotal trauma using high-resolution US, color-power Doppler, low mechanical index CEUS, and power Doppler after IV administration of contrast medium (SonoVue(®)). In the 24 cases that were positive, concordance between basal US and CEUS findings was grade 0 (absent) in 4 cases, grade 1 (low) in 3, grade 2 (moderate) in 8, and grade 3 (high) in 9. The relevance of the additional information provided by CEUS was classified as follows: high in 4/40 (10%), moderate 7/40 (17,5%), low 13/40 (32,5%), none in 14/40 (35%). Our findings demonstrate that CEUS is appreciably more sensitive in detecting damage caused by blunt scrotal trauma, particularly small lesions. It is also useful for differential diagnosis and marginalization of corpuscular fluid collections, fractures, and above all ruptures, which require immediate surgery. In our series 2 out of 3 (67%) patients with testicular rupture were diagnosed only by CEUS. We feel that the use of CEUS can significantly improve diagnostic confidence in cases of closed scrotal trauma although these conclusions need to be confirmed in larger case series.

Contrast-enhanced ultrasound imaging of active bleeding associated with hepatic and splenic trauma

PURPOSE

The aim of this study was to evaluate contrast-enhanced ultrasound (CEUS) imaging of active bleeding from hepatic and splenic trauma.

MATERIALS AND METHODS

Three hundred and ninety-two patients with liver or/and spleen trauma (179 liver and 217 spleen injuries), who underwent CEUS examinations following contrast-enhanced computed tomography (CT), were enrolled in this retrospective study over a period of >4 years. CEUS detected contrast medium extravasation or pooling in 16% (63/396) of liver or spleen lesions in 61 patients, which was confirmed by contrast-enhanced CT. Special attention was paid to observing the presence, location, and characteristics of the extravasated or pooled contrast medium.

RESULTS

The CEUS detection rate for active bleeding was not different from that of contrast-enhanced CT (p=0.333). Information from surgery, minimally invasive treatment and conservative treatment was used as reference standard, and the sensitivities of the two techniques were not different (p=0.122). Of 63 lesions in 61 patients, CEUS showed that 74.6% (47/63) (21 liver lesions and 26 spleen lesions) presented contrast medium extravasation or pooling, both in the organ and out the capsule, in 14.3% (9/63) and only outside the capsule in 11.1% (7/63). CEUS imaging of active bleeding from hepatic and splenic trauma presented various characteristics, and the sizes and shapes of the active bleeding due to contrast medium extravasation or pooling were variable.

CONCLUSIONS

CEUS can show the active bleeding associated with hepatic and splenic trauma with various imaging characteristics, thus making it possible to diagnose active bleeding using CEUS.

Management of liver trauma in adults

The liver is one of the most commonly injured organs in abdominal trauma. Recent advancements in imaging studies and enhanced critical care monitoring strategies have shifted the paradigm for the management of liver injuries. Nonoperative management of both low- and high-grade injuries can be successful in hemodynamically stable patients. Direct suture ligation of bleeding parenchymal vessels, total vascular isolation with repair of venous injuries, and the advent of damage control surgery have all improved outcomes in the hemodynamically unstable patient population. Anatomical resection of the liver and use of atriocaval shunt are rarely indicated.

Microbubble-enhanced US in body imaging: what role?

Contrast agents for ultrasonography (US) comprise microscopic bubbles of gas in an encapsulating shell. They are unique in that they interact with the imaging process, oscillating in response to a low-intensity ultrasound field and disrupting in response to a high-intensity field. New contrast-specific imaging modes allow US to show exquisite vascularity and tissue perfusion in real time and with excellent spatial resolution. In Europe, Asia, and Canada, to name only the most obvious, characterization of focal liver masses is the first and best established use of contrast-enhanced (CE) US, allowing for the noninvasive diagnosis of commonly encountered liver masses with comparable accuracy to that of computed tomography and magnetic resonance studies. CE US is a preferred modality for the difficult task of diagnosis of liver nodules detected on surveillance scans in those at risk for hepatocellular carcinoma. Newer body applications include the guidance of ablative intervention, monitoring activity of bowel inflammation in Crohn disease, characterization of kidney masses, especially cystic renal cell carcinoma, diagnosis of prostate cancer, and monitoring the response of tumors to antivascular drug therapies. Microbubble contrast agents are easy to use and robust; their use poses no risk of nephrotoxicity and requires no ionizing radiation. CE US plays a vital and expanding role that improves management and patient care.

Contrast-enhanced US evaluation in patients with blunt abdominal trauma()

INTRODUCTION

To evaluate the use of contrast-enhanced ultrasonography (CEUS) in patients with blunt abdominal trauma.

MATERIALS AND METHODS

A total of 133 hemodynamically stable patients were evaluated using ultrasonography (US), CEUS and multislice Computer Tomography (CT) da eliminare.

RESULTS

In 133 patients, CT identified 84 lesions: 48 cases of splenic injury, 21 of liver injury, 13 of kidney or adrenal gland injury and 2 of pancreatic injury. US identified free fluid or parenchymal abnormalities in 59/84 patients positive at CT and free fluid in 20/49 patients negative at CT. CEUS revealed 81/84 traumatic injuries identified at CT and ruled out traumatic injuries in 48/49 negative at CT. Sensitivity, specificity, positive and negative predictive values for US were 70.2%, 59.2%, 74.7% and 53.7%, respectively; for CEUS the values were 96.4%, 98%, 98.8% and 94.1%, respectively.

CONCLUSIONS

The study showed that CEUS is more accurate than US and nearly as accurate as CT, and CEUS can therefore be proposed for the initial evaluation of patients with blunt abdominal trauma.

Contrast-enhanced ultrasonography in blunt abdominal trauma: considerations after 5 years of experience

PURPOSE

The aim of the study was to evaluate the diagnostic capability of contrast-enhanced ultrasonography (CEUS) in a large series of patients with blunt abdominal trauma.

MATERIALS AND METHODS

We studied 133 haemodynamically stable patients with blunt abdominal trauma. Patients were assessed by ultrasonography (US), CEUS and multislice computed tomography (MSCT) with and without administration of a contrast agent. The study was approved by our hospital ethics committee (clinical study no. 1/2004/O).

RESULTS

In the 133 selected patients, CT identified 84 lesions; namely, 48 splenic, 21 hepatic, 13 renal or adrenal and two pancreatic. US identified free fluid or parenchymal alterations in 59/84 patients with positive CT and free fluid in 20/49 patients with negative CT. CEUS detected 81/84 traumatic lesions identified on CT and ruled out traumatic lesions in 48/49 patients with negative CT. The sensitivity, specificity and positive and negative predictive values of US were 70.2%, 59.2%, 74.7% and 53.7%, respectively, whereas those of CEUS were 96.4%, 98%, 98.8% and 94.1%, respectively.

CONCLUSIONS

Our study showed that CEUS is an accurate technique for evaluating traumatic lesions of solid abdominal organs. The technique is able to detect active bleeding and vascular lesions, avoids exposure to ionising radiation and is useful for monitoring patients undergoing conservative treatment.

CEUS in abdominal trauma: multi-center study

The objective of this study was to evaluate the concordance of US and contrast-enhanced US (CEUS) with CT in the assessment of solid organ injury following blunt trauma. Patients underwent complete US examination, including free fluid search and solid organ analysis. CEUS followed, using low-mechanical index techniques and SonoVue. CT was performed within 1 h. Among 156 enrolled patients, 91 had one or more abnormalities (n = 107) at CT: 26 renal, 38 liver, 43 spleen. Sensitivity, specificity, and accuracy for renal trauma at baseline US were 36%, 98%, and 88%, respectively, after CEUS values increased to 69%, 99%, and 94%. For liver baseline US values were 68%, 97%, and 90%; after CEUS were 84%, 99%, and 96%. For spleen, results were 77%, 96%, and 91% at baseline US and 93%, 99%, and 97% after CEUS. Per patient evaluation gave the following results in terms of sensitivity, specificity and accuracy: 79%, 82%, 80% at baseline US; 94%, 89%, and 92% following CEUS. CEUS is more sensitive than US in the detection of solid organ injury, potentially reducing the need for further imaging. False negatives from CEUS are due to minor injuries, without relevant consequences for patient management and prognosis.

Comparison of gray-scale contrast-enhanced ultrasonography with contrast-enhanced computed tomography in different grading of blunt hepatic and splenic trauma: an animal experiment

To compare the diagnostic value of contrast-enhanced ultrasonography (CEUS) with contrast-enhanced computed tomography (CECT) for the detection of different grading of solid organ injuries in blunt abdominal trauma in animals. A self-made miniature tools were used as models to simulate a blunt hepatic or splenic trauma in 16 and 14 anesthetized dogs, respectively. Baseline ultrasound, CEUS and CECT were used to detect traumatic injuries of livers and spleens. The degree of injuries was determined by CEUS according to the American Association for the Surgery of Trauma (AAST) scale and the results compared with injury scale based on CECT evaluation. CEUS showed 22 hepatic injury sites in 16 animals and 17 splenic injury sites in other 14 animals. According to AAST scale, 2 grade I, 4 grade II, 3 grade III, 5 grade IV and 2 grade V hepatic lesions were present in 16 animals; 2 grade I, 4 grade II, 6 grade III and 2 grade IV splenic lesions in 14 animals. On CECT scan, 21 hepatic and 17 splenic injuries were demonstrated. According to Becker CT scaling for hepatic injury, 1 grade I, 2 grade II, 4 grade III, 5 grade IV and 2 grade V hepatic injuries were present. On the basis of Buntain spleen scaling, 2 grade I, 5 grade II, 5 grade III, 2 grade IV splenic injuries were showed. After Spearman rank correlation analysis, the agreement of CEUS with CECT on the degree of hepatic and splenic injury is 93.3% and 92.9%, respectively. CT is currently considered as the reference method for grading blunt abdominal trauma, according to experiment results, CEUS grading showed high levels of concordance with CECT. CEUS can accurately determine the degree of injury and will play an important role in clinical application.

[The value of sonography in traumatology and orthopedics : Part 2: emergency diagnostics in blunt abdominal and thoracic trauma]

Ultrasound examinations in trauma patients should be done in the emergency department using curved-array (3.5-7.5 MHz) probes. Blunt trauma of the abdomen and thorax must be regarded as a single organ injury. Sonography is the imaging technique of first choice and has completely replaced peritoneal lavage. Paramount advantages are its ability to provide rapid information and reproducible results at short intervals and in a noninvasive manner. The sensitivity and specificity of sonography in detecting intraabdominal fluid are 97-100% and 80-90%, respectively. To achieve such good results, though, adequate education in ultrasound and state-of-the-art devices is crucial. Clinical experiences prove that standardized sonography must be part of polytrauma management and should be integrated in advanced trauma life support courses. Technical improvements with better image quality and miniaturization of hardware will contribute to increase the use of this technique. However, ultrasound does not replace computed tomography for follow-up in answering more sophisticated questions in multiple injured patients.

Hemostatic agents injected directly into hepatic injury sites for liver trauma hemorrhage under the guidance of contrast-enhanced ultrasound: an animal experiment

We investigated whether direct injection of hemostatic agents into injury sites under the guidance of contrast-enhanced ultrasound (CEUS) can decrease blood loss from liver trauma. Twelve adult healthy dogs underwent laparotomy, and a hepatic wound (6.0 x 4.5 cm) was created in each dog. All animals were divided randomly into two groups: the treatment group and the control group. In the treatment group, hemocoagulase Atrox (Solco Basle Ltd., Birsfelden, Switzerland) and absorbable cyanoacrylate were injected directly into the liver injury sites, and 0.9% normal saline was injected into the injury sites in the control group. Resuscitation volume in the treatment group was less than that in the control group (55 +/- 12 mL vs. 105 +/- 23 mL, p < 0.001). The control group presented bleeding from liver injury sites. Times of bleeding at the injury site in the treatment groups were 6 +/- 1 s. Both groups presented an-echo and/or hypo-echo contrast regions, with contrast material pooling in the injury sites before the therapy. After the injection, the contrast material pooling disappeared in the treatment group observed by CEUS. Gross examination of liver tissue revealed that the injury site that had been treated was covered by clot and glue membrane. Histopathologic examination showed that there was hemostitic glue embolizing the microvessels and inflammatory cell infiltration among hepatocytes. Direct injection of hemocoagulase Atrox and cyanoacrylate into the liver injury sites guided by CEUS can effectively reduce blood loss from liver trauma within a short time. This experimental study may suggest a possible treatment for liver trauma hemorrhage and provide an experimental evidence for treating blunt abdominal parenchyma organs trauma under the guidance of CEUS.

Contrast-enhanced sonographic guidance for local injection of a hemostatic agent for management of blunt hepatic hemorrhage: a canine study

OBJECTIVE

The purpose of this study was to determine whether injection of hemostatic agents directly into an injury site under the guidance of contrast-enhanced sonography can effectively control hemorrhage due to hepatic trauma.

MATERIALS AND METHODS

Fifteen mixed-breed dogs 2-3 years old and weighing 17-20 kg were anesthetized with intramuscular pentobarbital sodium (30 mg/kg). A special impacting device was used to induce hepatic trauma with a mean force of 5.3 +/- 0.3 kN. Twelve of the 15 dogs had hepatic injuries with a grade of 3-4 or 4. The 12 dogs were divided into treatment and control groups. In the treatment group, hemocoagulase atrox (1 Klobusitzky unit) and alpha-cyanoacrylate (1 mL) were administered by transcutaneous injection into the injury site and the bleeding site, respectively, under the guidance of contrast-enhanced sonography. The control group received injections of 0.9% normal saline solution.

RESULTS

After injection into the treatment group, no active bleeding was observed at the liver injury site. In the control group, evidence of active bleeding was present on contrast-enhanced sonograms. Laparotomy of the treatment group showed that hepatic injuries had been covered and adhered by clots and the glue membrane of the hemostatic agents and that free intraperitoneal blood volume was significantly less than in the control group (p < 0.001). Bleeding did not stop in the control group.

CONCLUSION

In dogs, transcutaneous local injection of hemostatic agents can effectively reduce blood loss due to severe liver trauma. Because it is simple, convenient, and effective, the technique may be an alternative for bedside and battlefield management of hepatic hemorrhage due to trauma.

Percutaneous injection therapy for blunt splenic trauma guided by contrast-enhanced ultrasonography

OBJECTIVE

The purpose of this study was to investigate the application of contrast-enhanced ultrasonography (CEUS) in managing blunt splenic trauma and the effectiveness of CEUS-guided percutaneous injection therapy.

METHODS

Six patients with grade 3 or 4 splenic injuries as determined by CEUS and contrast-enhanced computed tomography were given hemocoagulase atrox and absorbable cyanoacrylate percutaneously, which were injected into the injury region and active bleeding site, respectively, under CEUS guidance. Immediately after the procedure and 1 and 3 days, 1 and 2 weeks, and 1 and 6 months after the procedure, follow-up CEUS up was performed in all patients.

RESULTS

Among the 6 patients, 4 cases of CEUS-guided hemostatic injection were successful without complications. Rehemorrhage occurred in 1 patient, and a traumatic arteriovenous fistula occurred in another; repeated injection therapy in these 2 patients was effective. During the follow-up, there were no complications, and spleen perfusion recovered gradually.

CONCLUSIONS

Contrast-enhanced ultrasonography can be used to guide percutaneous injection therapy and therefore achieve the goal of using interventional ultrasonography in managing splenic trauma.

Hemostasis of active bleeding from the liver with percutaneous microwave coagulation therapy under contrast-enhanced ultrasonographic guidance: an experimental study

OBJECTIVE

The purpose of this study was to investigate the feasibility of percutaneous microwave coagulation therapy (PMCT) guided by contrast-enhanced ultrasonography (CEUS) for controlling active bleeding in rabbit livers.

METHODS

Twenty actively bleeding rabbit liver models, produced with an 18-gauge semiautomatic biopsy needle and confirmed with CEUS, were randomly divided into 2 groups: a PMCT group (n=10, with a microwave antenna placed into the bleeding site under ultra-sonographic guidance and worked at 60 W for 30 seconds on average) and a control group (n=10, with the active bleeding site not treated). After therapy procedures were performed, lactated Ringer's solution resuscitation was then performed in both groups to maintain the mean arterial pressure at 70 mm Hg for 1 hour. The intraperitoneal blood loss, total resuscitation volume, mean arterial pressure, and hematocrit value were recorded. Macroscopic and microscopic examinations were performed at the end of the study.

RESULTS

After PMCT, the former bleeding site appeared on CEUS as a round or an oval area devoid of contrast. The PMCT group had lower blood loss (30.4+/-7.2 versus 101.6 +/- 18.2 mL; P< .05) and a lower total resuscitation volume (56.5+/-10 versus 186+/-36.6 mL; P< .05) than the control group. The mean hematocrit value in the PMCT group was significantly higher than that in the control group (26%+/-4% versus 19%+/-4%; P< .05) at the end of the experiment.

CONCLUSIONS

Contrast-enhanced ultrasonographically guided PMCT significantly decreased blood loss in a rabbit model of active liver bleeding. It provides a simple and quick method to control blood loss in liver injuries with active bleeding.

Emergency real-time contrast-enhanced ultrasonography for detection of solid organ injuries

BACKGROUND

There is no controversy about the use of CT for detection of internal injuries in patients with high-energy multitrauma. However, in most patients isolated blunt abdominal trauma is mild or moderate and the risk of injury to organs other than the liver, spleen or kidneys is minimal. CT scanning exposes patients to radiation, and may often be avoided if significant damage to these three organs can be visualized by contrast-enhanced ultrasonography (CEUS).

MATERIALS AND METHODS

In our series SonoVue (Bracco, Milan) and Siemens Acuson Sequoia ultrasound machines were used. Initially patients with injuries detected by CT were examined using CEUS. Subsequently CEUS was used as the first and only modality in patients with mild or moderate blunt abdominal trauma to one flank, provided that they were able to cooperate and were otherwise suitable for US examination.

RESULTS

CEUS was able to sensitively detect lacerations and haematomas in the liver, spleen and kidneys in cooperative patients. CEUS also demonstrated very thin lacerations of the parenchyma of these organs. These results were also found in children.

CONCLUSION

In our experience CEUS is an accurate and valuable tool for the detection or exclusion of parenchymal damage to the liver, spleen and kidneys. With the proper organization, standardized dynamic documentation and well-trained sonographers, CEUS may replace CT in many patients with mild to moderate blunt abdominal trauma, thus avoiding unnecessary exposure to radiation in this often young and healthy population.

Focal liver lesions: role of contrast-enhanced ultrasound

The introduction of microbubble contrast agents and the development of contrast-specific techniques have opened new possibilities in liver imaging. Initially, only intermittent imaging with Doppler detection was available. Second-generation contrast agents and low mechanical index real-time scanning techniques are decisive advances that enable convenient liver examinations with high sensitivity and specificity. Hepatic lesions usually show typical perfusion and enhancement patterns through the various contrast phases, which help their characterization. Several published studies and the daily clinical routine show that, as opposed to conventional ultrasound (US), contrast-enhanced US can substantially improve detection and differentiation of focal liver lesions. Today, contrast-enhanced US is the dynamic imaging modality of choice for differentiation of focal liver lesions. Contrast uptake patterns of the most relevant liver lesions, as well as important clinical indications are presented and discussed.

The value of contrast-enhanced gray-scale ultrasound in the diagnosis of hepatic trauma: an animal experiment

BACKGROUND

Conventional ultrasonography (US) shows markedly lower sensitivity in detecting parenchymal injury and active bleeding in abdominal organs. This study was designed to evaluate the utility of contrast-enhanced US (CEUS) in the diagnosis of blunt trauma and active hemorrhage of the liver in an animal model.

METHODS

Sixteen blunt injuries and 40 lacerations with active hemorrhage were created in livers of 14 pigs using laparotomy. The lacerations were divided into two groups: group I, in which the velocity of the traumatized artery was >20 cm/s; and group II, in which the velocity of the traumatized artery was < or =20 cm/s. Twenty minutes after the blunt trauma and immediately after the laceration was created, conventional US and CEUS were performed to observe the sonographic characteristics of trauma.

RESULTS

The sensitivity of CEUS in detecting blunt hepatic trauma (100%; 16 of 16) was significantly higher than that of conventional US (37.5%; 6 of 16) (p < 0.001) based on the histopathology gold standard. Active hemorrhage was clearly detected as hyperechoic enhanced linear or clumpy regions in all of the lacerations in group I (100%; 20 of 20) and in 65% (13 of 20) of the lacerations in group II on CEUS. Acoustic shadowing was observed posterior to the enhanced hemorrhagic site in 12 lacerations from group I and in five lacerations from group II.

CONCLUSION

In this animal model, CEUS was found to be useful in detecting blunt trauma and active hemorrhage in the liver, which might significantly improve the efficacy of US for the diagnosis of hepatic trauma.

Microbubble ultrasound contrast agents: an update

Microbubble contrast agents for ultrasound (US) have gained increasing interest in recent years, and contrast-enhanced US (CEUS) is a rapidly evolving field with applications now extending far beyond the initial improvements achieved in Doppler US. This has been achieved as a result of the safe profile and the increased stability of microbubbles persisting in the bloodstream for several minutes, and also by the availability of specialized contrast-specific US techniques, which allow a definite improvement in the contrast resolution and suppression of signal from stationary tissues. CEUS with low transmit power allows real-time scanning with the possibility of prolonged organ insonation. Several reports have described the effectiveness of microbubble contrast agents in many clinical applications and particularly in the liver, spleen, and kidneys. CEUS allows the assessment of the macrovasculature and microvasculature in different parenchymas, the identification and characterization of hepatic and splenic lesions, the depiction of septal enhancement in cystic renal masses, and the quantification of organ perfusion by the quantitative analysis of the echo-signal intensity. Other fields of application include the assessment of abdominal organs after traumas and the assessment of vesico-ureteral reflux in children. Finally, tumor-targeted microbubbles make possible the depiction of specific biologic processes.

Hemorrhage control using high intensity focused ultrasound

Hemorrhage control is a high priority task in advanced trauma care, because hemorrhagic shock can result in less than a minute in cases of severe injuries. Hemorrhage was found to be solely responsible for 40-50% of traumatic civilian and battlefield deaths in recent years. The majority of these deaths were due to abdominal and pelvic injuries with hidden and inaccessible bleeding of solid organs such as liver, spleen, and kidneys, as well as major blood vessels. High intensity focused ultrasound (HIFU) offers a promising method for hemorrhage control. An important advantage of HIFU is that it can deliver energy to deep regions of tissue where hemorrhage is occurring, allowing cauterization at depth of parenchymal tissues, or in difficult-to-access anatomical regions, while causing no or minimal biological effects in the intervening and surrounding tissues. Moreover, HIFU can cause both thermal and mechanical effects that are shown to work synergistically for rapid hemorrhage control. The major challenges of this method are in development of bleeding detection techniques for accurate localization of the injury sites, delivery of large HIFU doses for profuse bleeding cases, and ensuring safety when critical structures are in the vicinity of the injury. Future developments of acoustic hemostasis technology are anticipated to be for applications in peripheral vascular injuries where an acoustic window is usually available, and for applications in the operating room on exposed organs.

Detection of bleeding in injured femoral arteries with contrast-enhanced sonography

OBJECTIVE

The purpose of this study was to investigate the feasibility of detecting acute arterial bleeding by means of contrast-enhanced sonography.

METHODS

Puncture injury was produced transcutaneously with an 18-gauge needle in 26 femoral arteries (13 in the control group and 13 in the contrast-enhanced group) of rabbits. A sonographic contrast agent (Optison; Mallinckrodt Inc, St Louis, MO) was administered intravenously at a dose of 0.06 to 0.07 mL/kg. Sonography of the femoral arteries was performed before and after injury, both before and after injection of Optison, with B-mode imaging, color Doppler imaging, and pulse inversion harmonic imaging (PIHI).

RESULTS

The specific location of active bleeding could not be visualized in B-mode and PIHI scans in the control group (no Optison injection). After administration of Optison, the bleeding site was visualized because of the increased echogenicity of the extravasated blood at the puncture site in both B-mode imaging and PIHI. In color Doppler images, bleeding sites were localized successfully in 84.6% of the cases in the presence of Optison and in 30.8% of the cases without Optison. Histologic examination (light microscopy) of the hematoma confirmed the presence of contrast agent microbubbles in the extravascular space surrounding the artery.

CONCLUSIONS

Contrast-enhanced sonography may provide an effective method for detecting arterial bleeding.

Appearance of Solid Organ Injury with Contrast-Enhanced Sonography in Blunt Abdominal Trauma: Preliminary Experience

OBJECTIVE

The purpose of this study was to compare the detection rate of injury and characterize imaging findings of contrast-enhanced sonography and non-contrast-enhanced sonography in the setting of confirmed solid organ injury.

SUBJECTS AND METHODS

This prospective study involved identifying hepatic, splenic, and renal injuries on contrast-enhanced CT. After injury identification, both non-contrast-enhanced sonography and contrast-enhanced sonography were performed to identify the possible injury and to analyze the appearance of the injury. The sonographic appearance of hepatic, splenic, and renal injuries was then analyzed, and the conspicuity of the injuries was graded on a scale from 0 (nonvisualization) to 3 (high visualization).

RESULTS

Non-contrast-enhanced sonography revealed 11 (50%) of 22 injuries, whereas contrast-enhanced sonography depicted 20 (91%) of 22 injuries. The average grade for conspicuity of injuries was increased from 0.67 to 2.33 for spleen injuries and from 1.0 to 2.2 for liver injuries comparing non-contrast-enhanced with contrast-enhanced sonography, respectively, on a scale from 0, being nonvisualization, to 3, being high visualization. The splenic injuries appeared hypoechoic with occasional areas of normal enhancing splenic tissue within the laceration with contrast-enhanced sonography. Different patterns were observed in liver injuries including a central hypoechoic region. In some liver injuries there was a surrounding hyperechoic region.

CONCLUSION

Contrast-enhanced sonography greatly enhances visualization of liver and spleen injuries compared with non-contrast-enhanced sonography. Solid organ injuries usually appeared hypoechoic on contrast-enhanced sonography, but often a hyperechoic region surrounding the injury also was identified with liver injuries.

Ultrasound contrast agents: an overview

With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI<0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating vasospasm after subarachnoid haemorrhage). An important situation where demonstrating tissue devitalisation is important is in interstitial ablation of focal liver lesions: using microbubble contrast agents at the end of a procedure allows immediate evaluation of the adequacy of the ablation which can be extended if needed; this is much more convenient and cost-saving than moving the patient to CT and perhaps needing an additional ablation session at a later date. Similar considerations suggest that contrast-enhanced ultrasound might have a role in abdominal trauma: injury to the liver, spleen and kidneys can be assessed rapidly and repeatedly if necessary. Its role here alongside dynamic CT remains to be evaluated. Infarcts or ischaemia and regions of abnormal vascularity, especially in malignancies, in the kidneys and spleen seem to be useful and improved detection of the neovascularisation of ovarian carcinomas is promising. Similar benefits in the head-and-neck and in the skin while the demonstration of the neovascularisation of atheromatous plaques and of aggressive joint inflammation offer interesting potentials.

Active abdominal bleeding: contrast-enhanced sonography

Active contrast medium extravasation is a recognized and important angiographic and computed tomographic (CT) sign of bleeding. It is an indicator of active, ongoing, and potentially life-threatening hemorrhage and, hence, of the need for an immediate surgical or interventional treatment. Sonography (US) is frequently used as the first imaging option for screening patients with traumatic and nontraumatic abdominal emergencies. Owing to the current possibilities of low-mechanical index, real-time, contrast-specific systems, it is now possible to detect a contrast leakage by using US. This finding opens new possibilities in the assessment and management of several abdominal emergencies, including trauma (initial workup and monitoring), spontaneous hematomas, and rupture of aneurysms or masses. This article describes the technique, findings, possibilities, and limitations of contrast-enhanced US in the evaluation of active abdominal bleeding.

Color power Doppler US and contrast-enhanced US features of abdominal solid organ injuries

Utilization of color power Doppler and sonographic contrast agents to basic ultrasound (US) further improve the detection and characterization of abdominal injuries, increasing the diagnostic accuracy and value of US as an important technique in the evaluation of the abdominal trauma. This paper provides an illustrated summary of our clinical experience with color power Doppler US (CD-US) and contrast-enhanced US (CE-US) in the evaluation of abdominal solid organ injuries, involving 32 documented cases over a 2-year period. The findings of the CD-US and CE-US were compared with those provided by state-of-the-art contrast-enhanced multidetector 16-row CT.