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

Bedside US imaging in multiple trauma patients. Part 1: US findings and techniques

OBJECTIVES

The aim of this review article is to present the current views and visions of the role of ultrasound (US) in the management of patients with multiple trauma. The article is divided into two parts. Part 1 (US findings and techniques) will mainly deal with the technical aspects of US imaging in trauma patients and is written also for educational purposes. Part 2 (pathophysiology and US imaging in trauma patients) will deal with integration of US in the clinical and pathophysiological management of multiple trauma patients.

METHODS

A non-systematic review of the literature through PubMed search (restricted to the last 10 years) of original articles and review articles.

RESULTS

80 publications were selected for Part 1. Of these 80 articles, the author selected 50 according to personal criteria on the basis of their innovative or original contents (48 original articles and 2 literature review articles); 19 articles were furthermore extracted from the references of the selected publications. The information extracted from these 69 publications was organized into sections dealing with different fields of applications of US imaging in multiple trauma patients.

CONCLUSIONS

US imaging in trauma has evolved from the initial use, i.e., early diagnosis of peritoneal effusion (focused abdominal sonography for trauma), to a wider use known as resuscitative ultrasonography, and is today considered as an extension of physical examination to implement a more effective approach to clinical problems and increase the timeliness and safety of interventions.

Is non-operative management safe and effective for all splenic blunt trauma? A systematic review

Introduction

The goal of non-operative management (NOM) for blunt splenic trauma (BST) is to preserve the spleen. The advantages of NOM for minor splenic trauma have been extensively reported, whereas its value for the more severe splenic injuries is still debated. The aim of this systematic review was to evaluate the available published evidence on NOM in patients with splenic trauma and to compare it with the operative management (OM) in terms of mortality, morbidity and duration of hospital stay.

Methods

For this systematic review we followed the "Preferred Reporting Items for Systematic Reviews and Meta-analyses" statement. A systematic search was performed on PubMed for studies published from January 2000 to December 2011, without language restrictions, which compared NOM vs. OM for splenic trauma injuries and which at least 10 patients with BST.

Results

We identified 21 non randomized studies: 1 Clinical Controlled Trial and 20 retrospective cohort studies analyzing a total of 16,940 patients with BST. NOM represents the gold standard treatment for minor splenic trauma and is associated with decreased mortality in severe splenic trauma (4.78% vs. 13.5% in NOM and OM, respectively), according to the literature. Of note, in BST treated operatively, concurrent injuries accounted for the higher mortality. In addition, it was not possible to determine post-treatment morbidity in major splenic trauma. The definition of hemodynamic stability varied greatly in the literature depending on the surgeon and the trauma team, representing a further bias. Moreover, data on the remaining analyzed outcomes (hospital stay, number of blood transfusions, abdominal abscesses, overwhelming post-splenectomy infection) were not reported in all included studies or were not comparable, precluding the possibility to perform a meaningful cumulative analysis and comparison.

Conclusions

NOM of BST, preserving the spleen, is the treatment of choice for the American Association for the Surgery of Trauma grades I and II. Conclusions are more difficult to outline for higher grades of splenic injury, because of the substantial heterogeneity of expertise among different hospitals, and potentially inappropriate comparison groups.

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.

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.

Contrast-enhanced ultrasound performed under urgent conditions. Indications, review of the technique, clinical examples and limitations

Contrast-enhanced ultrasound (CEUS) is an imaging technique with various indications, most of which refer to scheduled examinations. However, CEUS can also be performed under urgent conditions for the investigation of many different clinical questions. This article reviews basic physics of ultrasound contrast agents and examines the commonest urgent clinical applications of CEUS. These include, among others, abdominal solid organ trauma and infarcts, scrotal and penile pathology and blood vessel imaging. Patients can be examined with a very short time delay at their bedside, without exposure to ionising radiation or risk of anaphylactic reaction and renal failure, while contraindications are minimal. CEUS technique is described for various urgent indications and imaging examples from our department's experience are presented. Safety matters and limitations of CEUS are also mentioned. Teaching Points • Contrast-enhanced ultrasound (CEUS) can be performed urgently for various clinical applications. • Abdominal indications include solid organ trauma and infarcts. • CEUS in abdominal organ trauma correlates well with CT and can replace it for patient follow-up. • CEUS images testicular torsion, infection and infarction, as well as testicular and penile trauma. • Blood vessels can be assessed with CEUS for obstruction, aneurysm, thrombosis and dissection.

Computed tomography for pancreatic injuries in pediatric blunt abdominal trauma

AIM: To evaluate the efficacy of computed tomography scan in diagnosing and grading the pattern of pancreatic injuries in children.

METHODS: We conducted a retrospective study to review medical files of children admitted with blunt pancreatic injuries to the Maternity and Children Hospital Al-Madina Al-Munawwarah, Kingdom of Saudi Arabia. The demographic details and mechanisms of injury were recorded. From the database of the Picture Archiving and Communication System of the radiology department, multidetector computed tomography (MDCT) images of the pancreatic injuries, severity, type of injuries and grading of pancreatic injuries were established.

RESULTS: Seven patients were recruited in this study over a period of 5 years; 5 males and 2 females with a mean age of 7 years (age range 5-12 years). Fall from height was the most frequent mechanism of injury, reported in 5 (71%), followed by road traffic accident (1 patient, 14%) and cycle handlebar (1 patient, 14%) injuries. According to the American Association for the Surgery of Trauma grading system, 1 (14%) patient sustained Grade I, 1 (14%) Grade II, 3 (42%) Grade III and 2 (28%) patients were found to have Grade V pancreatic injuries. This indicated a higher incidence of severe pancreatic injuries; 5 (71.4%) patients were reported to have Grade III and higher on the injury scale. Three (42%) patients had associated abdominal organ injuries.

CONCLUSION: Pediatric pancreatic injuries due to blunt abdominal trauma are rare. The majority of the patients sustained extensive pancreatic injuries. MDCT findings are helpful and reliable in diagnosing and grading the pancreatic injuries.

Imaging findings of ruptured abdominal and pelvic tumors

A variety of abdominal and pelvic tumors can present with rupture leading to hemoperitoneum/hemoretroperitoneum or peritonitis. Imaging plays an important role in the diagnosis of hemorrhage or peritonitis as well as in the detection of ruptured tumors or organs. In this article, we illustrate the imaging findings of ruptured tumors arising in the abdominal and pelvic organs while excluding those of ruptured tumors arising in the stomach and intestines. It is important for the radiologists to understand the mechanisms involved in tumor rupture and recognize the imaging features of ruptured tumors according to the organs involved because this will permit the exact diagnosis of ruptured tumors, thereby facilitating prompt and effective treatment.

Contrast-enhanced ultrasound in abdominal imaging

The administration of a contrast agent is considered an essential tool to evaluate abdominal diseases using Ultrasound. The most targeted organ is the liver, especially to characterize focal liver lesions and to assess the response to percutaneous treatment. However, the expanding abdominal indications of contrast-enhanced ultrasound make this technique an important tool in the assessment of organ perfusion including the evaluation of ischemic, traumatic, and inflammatory diseases.

Current and potential renal applications of contrast-enhanced ultrasound

The combination of microbubble technology and complementary ultrasound techniques has resulted in the development of contrast-enhanced ultrasound (CEUS) and, although initial clinical applications largely focussed on the liver, these are now becoming more diverse. With regard to the kidney, it is a safe, well-tolerated, and reproducible technique, and in selected cases, can obviate the need for computed tomography or magnetic resonance imaging. A clear advantage is the absence of nephrotoxicity. With respect to the current and potential renal applications, it is a useful technique in the evaluation of pseudotumours, acute pyelonephritis, renal tumours, cystic lesions, vascular insults, and renal transplantation. It may also be of value for monitoring the kidney following anti-angiogenic treatment or nephron-sparing interventional techniques for renal tumours. Assessment of microvascular perfusion using time-intensity curves is also likely to have further far-reaching applications in the kidney as well as other organs.

[Contrast-enhanced sonography for blunt force abdominal trauma]

With the introduction of second generation ultrasound contrast agents, contrast-enhanced ultrasound (CEUS) has become available as an adjunct to the conventional FAST (focused assessment with sonography in trauma) protocol and B-mode sonography of the abdomen after blunt force abdominal trauma. Results from several controlled studies indicate excellent diagnostic accuracy of CEUS for the exclusion of clinically relevant parenchymal injuries after blunt force abdominal trauma. Particularly in younger, hemodynamically stable patients this technique could contribute to a reliable exclusion of parenchymal injuries without the use of ionizing radiation. This report provides details on the technical performance of CEUS, shows examples of typical CEUS findings after blunt abdominal trauma and summarizes the current clinical evidence regarding the use of CEUS after blunt abdominal trauma.

Sonography of the spleen

This pictorial essay will review and discuss the aspects of differential diagnosis with splenic sonography, including recent literature and exemplary pictorial sonographic cases. Although the spleen is well evaluated by computed tomography and magnetic resonance imaging, sonography has certain advantages, including its ubiquitous availability, lack of ionizing radiation, and low cost. Sonography of the spleen plays an important role in emergency diagnosis of splenic rupture and hemorrhage. The additional use of contrast-enhanced sonography can improve the diagnostic validity. Depending on the indication, sonography of the spleen is especially important for oncologic differential diagnosis of focal lesions, follow-up examinations, and image guidance of therapeutic interventions.

Liver trauma diagnosis with contrast-enhanced ultrasound: interobserver variability between radiologist and emergency physician in an animal study

OBJECTIVE

The purpose of our study was to evaluate interobserver variability between the radiologist and emergency physician in detecting blunt liver trauma by conventional and contrast-enhanced ultrasound (US) (CEUS).

METHODS

We created 20 sites of blunt liver trauma in rabbits and performed conventional US and CEUS on the animals. A radiologist and an emergency physician independently evaluated the degree of liver trauma. Using contrast-enhanced computed tomography as a reference standard, the diagnostic performance of US and CEUS was calculated. Interobserver variability between radiologist and emergency physician was compared before and after contrast enhancement of US.

RESULTS

Overall sensitivity and specificity for detecting liver trauma on conventional US, regardless of the degree of trauma, were 61.1% and 100% for the radiologist and 50% and 100% for the emergency physician. On CEUS, the sensitivity and specificity were 94.4% and 100% for both the radiologist and emergency physician. The interobserver agreement between emergency physician and radiologist increased from 0.867 to 0.955 after contrast enhancement on US.

CONCLUSIONS

Contrast-enhanced US may permit a more accurate diagnosis for liver trauma than conventional US by both the radiologist and emergency physician. Contrast-enhanced US may also reduce interobserver variability for this diagnosis.

The current role of contrast-enhanced ultrasound (CEUS) imaging in the evaluation of renal pathology

BACKGROUND

By using a microbubble contrast agent and contrast-specific imaging software, the contrast-enhanced ultrasound (CEUS) is able to depict the micro and macrocirculation of the target organ.

METHODS

A review of the peer reviewed literature was done regarding the current role of ultrasound CEUS imaging in the evaluation of renal pathology with reference to the diagnosis of renal ischaemia, in the characterization of complex cystic lesions and in those with equivocal enhancement at CT.

RESULTS

CEUS provides information on tissue perfusion and may play a role in kidney mass characterization similar to the role of contrast-enhanced CT and MRI. In this context, the characterization of cystic lesions is probably the most consolidated field of application of contrast agents on kidney ultrasound imaging. Finally, CEUS provides a good alternative to CT, especially in patients with contraindications to iodinated contrast agents.

CONCLUSIONS

The usefulness of CEUS in these applications is confirmed by extensive literature production and this article focuses on the potential clinical applications of recent advances in CEUS technology in urology.

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.

Imaging of perfusion using ultrasound

Ultrasound can be used to image perfusion in two ways: the traditional one using Doppler and the more recent using microbubble contrast agents. Doppler is simple to use and inexpensive but is limited to larger vessels with faster flow rates. It cannot interrogate the microvasculature because bulk tissue movement is faster than capillary flow. It has been used for liver and tumour flow. Contrast studies are much richer and can assess both the macro- and microcirculation. One approach analyses the time-intensity curves in a region of interest, e.g. a tumour, myocardium, brain, following bolus i.v. injection. Another approach measures the time taken for the microbubbles to cross a vascular bed of interest. These arrival times can be useful for the liver in both diffuse and focal diseases and for the kidney. Features derived from time-intensity curves following bolus i.v. injections of microbubbles form sensitive early indicators of the vascular response of tumours to antivascular drugs. This approach, known as dynamic contrast-enhanced ultrasound (DCE-US), has been accepted as a valid technique for monitoring tumour response by several authorities.

Portable ultrasonography in mass casualty incidents: The CAVEAT examination

Ultrasonography used by practicing clinicians has been shown to be of utility in the evaluation of time-sensitive and critical illnesses in a range of environments, including pre-hospital triage, emergency department, and critical care settings. The increasing availability of light-weight, robust, user-friendly, and low-cost portable ultrasound equipment is particularly suited for use in the physically and temporally challenging environment of a multiple casualty incident (MCI). Currently established ultrasound applications used to identify potentially lethal thoracic or abdominal conditions offer a base upon which rapid, focused protocols using hand-carried emergency ultrasonography could be developed. Following a detailed review of the current use of portable ultrasonography in military and civilian MCI settings, we propose a protocol for sonographic evaluation of the chest, abdomen, vena cava, and extremities for acute triage. The protocol is two-tiered, based on the urgency and technical difficulty of the sonographic examination. In addition to utilization of well-established bedside abdominal and thoracic sonography applications, this protocol incorporates extremity assessment for long-bone fractures. Studies of the proposed protocol will need to be conducted to determine its utility in simulated and actual MCI settings.

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.

Effectiveness and safety of CEUS-guided haemostatic injection for blunt splenic trauma: an animal experiment

The aim of this study was to investigate whether complications occur after haemostatic agents are injected into blunt splenic injuries. After undergoing ultrasound (US), contrast-enhanced US (CEUS) and contrast-enhanced computed tomography (CECT) examinations, dogs with grade III-IV injury received the minimally invasive therapy. After treatment, CEUS was performed to observe changes in the regions treated. In the immediate group, dogs underwent laparotomy 30 min after treatment to observe the haemostatic effect. In the survival group, animals underwent CEUS and CECT examinations to observe the short-term healing outcome and complications at 3, 7, 14, and 21 days after the injection. After undergoing CEUS and CECT examinations, 12 dogs with grade III-IV injury received the minimally invasive therapy. Before injection, CEUS examinations showed anechoic and/or hypoechoic perfusion defects and active bleeding at the injury sites, and CECT showed traumatic lesions as low-density regions without enhancement. After treatment, CEUS demonstrated the disappearance of active bleeding, and hyperechoic spots emerged at the injury sites. Uneven density regions were displayed on CECT. Treated areas were covered by blood clots and glue membrane in the immediate-group animals. Three weeks later, CEUS showed a decrease of hyperechoic spots in the survival group, and the splenic parenchyma enhanced uniformly on CECT. Laparotomy showed that the greater omentum had moved upwards and partly covered the wound in four animals, and the injury sites had completely healed. Histopathological examination showed that fibrous connective tissue covered the splenic capsule and that the haemostatic glue had degraded. No complication occurred, such as delayed splenic haemorrhage, splenic abscesses, splenic pseudoaneurysms, intestinal obstruction or intestinal adhesions. CEUS-guided haemostatic injection is not only effective in stopping active bleeding immediately, but it is also safe in that no complications occurred during the 3 weeks of follow-up. This study indicates that CEUS-guided percutaneous injection may provide a safe, feasible and effective therapy for blunt splenic trauma.

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.

Ultrasound in trauma

Point-of-care ultrasound is well suited for use in the emergency setting for assessment of the trauma patient. Currently, portable ultrasound machines with high-resolution imaging capability allow trauma patients to be imaged in the pre-hospital setting, emergency departments and operating theatres. In major trauma, ultrasound is used to diagnose life-threatening conditions and to prioritise and guide appropriate interventions. Assessment of the basic haemodynamic state is a very important part of ultrasound use in trauma, but is discussed in more detail elsewhere. Focussed assessment with sonography for Trauma (FAST) rapidly assesses for haemoperitoneum and haemopericardium, and the Extended FAST examination (EFAST) explores for haemothorax, pneumothorax and intravascular filling status. In regional trauma, ultrasound can be used to detect fractures, many vascular injuries, musculoskeletal injuries, testicular injuries and can assess foetal viability in pregnant trauma patients. Ultrasound can also be used at the bedside to guide procedures in trauma, including nerve blocks and vascular access. Importantly, these examinations are being performed by the treating physician in real time, allowing for immediate changes to management of the patient. Controversy remains in determining the best training to ensure competence in this user-dependent imaging modality.

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.

Contrast-enhanced ultrasonography with SonoVue: differentiation between benign and malignant lesions of the spleen

OBJECTIVE

We investigated the ability of contrast-enhanced ultrasonography with SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal splenic lesions.

METHODS

In a prospective study we investigated 35 lesions in 35 patients (24 male and 11 female; mean age +/- SD, 54 +/- 15 years) with focal splenic lesions detected by B-mode ultrasonography. After intravenous injection of 1.2 to 2.4 mL of SonoVue, the spleen was examined continuously for 3 minutes using low-mechanical index ultrasonography with contrast-specific software. The final diagnosis was established by histologic examination, computed tomography, or magnetic resonance imaging.

RESULTS

In 14 patients, the splenic lesions were malignant (metastasis, n = 6; non-Hodgkin lymphoma, n = 6; and Hodgkin lymphoma, n = 2). In 21 patients, the focal splenic lesions were benign (ischemic lesion, n = 6; echogenic cyst, n = 5; abscess, n = 4; hemangioma, n = 3; hematoma, n = 1; hemophagocytosis syndrome, n = 1; and splenoma, n = 1. Typical findings for benign lesions were 2 arrival patterns: no contrast enhancement (neither in the early nor in the parenchymal phase; P < .05) and the beginning of contrast enhancement in the early phase followed by contrast enhancement in the parenchymal phase 60 seconds after injection. In contrast, the combination of contrast enhancement in the early phase followed by rapid wash-out and demarcation of the lesion without contrast enhancement in the parenchymal phase (60 seconds after injection) was typical for malignant lesions (P < .001).

CONCLUSIONS

Contrast-enhanced ultrasonography is helpful in the differentiation between benign and malignant lesions of the spleen.

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.

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.

Focused assessment with sonography for trauma: the FAST scan

Focused assessment with sonography for trauma or focused abdominal sonography for trauma — the FAST scan, has become a useful modality for the initial evaluation of patients with blunt abdominal trauma. The technique is used to identify free fluid in the abdomen and pelvis and to detect the presence of a pericardial effusion. FAST can be performed by any trained individual, not necessarily a sonographer or radiologist, aiding in the immediate availability of this technique in the emergency situation. We will discuss the applications and sensitivity of this technique in trauma and review the potential pitfalls and limitations which need to be understood if this technique is to be safely applied. The use of FAST for the detection of pneumothoraces in trauma and other advances in FAST scanning, such as scoring systems and paediatric FAST are also reviewed.

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

PURPOSE

To prospectively compare the sensitivity and specificity of ultrasonography (US) with those of contrast material-enhanced US in the depiction of solid organ injuries in children with blunt abdominal trauma, with contrast-enhanced computed tomography (CT) as the reference standard.

MATERIALS AND METHODS

The study protocol was approved by the ethics board, and written informed consent was obtained from parents. US, contrast-enhanced US, and contrast-enhanced CT were performed in 27 consecutive children (19 boys, eight girls; mean age, 8.9 years +/- 2.8 [standard deviation]) with blunt abdominal trauma to determine if solid abdominal organ injuries were present. Sensitivity, specificity, agreement, accuracy, number of lesions correctly identified, and positive and negative predictive values were determined for US and contrast-enhanced US, as compared with contrast-enhanced CT.

RESULTS

In 15 patients, contrast-enhanced CT findings were negative. Contrast-enhanced CT depicted 14 solid organ injuries in 12 patients. Lesions were in the spleen (n = 7), liver (n = 4), right kidney (n = 1), right adrenal gland (n = 1), and pancreas (n = 1). Contrast-enhanced US depicted 13 of the 14 lesions in 12 patients with positive contrast-enhanced CT findings and no lesions in the patients with negative contrast-enhanced CT findings. Unenhanced US depicted free fluid in two of 15 patients with negative contrast-enhanced CT findings and free fluid, parenchymal lesions, or both in eight of 12 patients with positive contrast-enhanced CT findings. Overall, the diagnostic performance of contrast-enhanced US was better than that of US, as sensitivity, specificity, and positive and negative predictive values were 92.2%, 100%, 100%, and 93.8%, respectively.

CONCLUSION

Contrast-enhanced US was almost as accurate as contrast-enhanced CT in depicting solid organ injuries in children.

Contrast-Enhanced Ultrasound for Blunt Abdominal Trauma

Sonography is widely used in the initial diagnostic assessment of blunt abdominal trauma in adults and children. It has been formally incorporated worldwide into the routine armamentarium available for emergency diagnosis and treatment as a means of rapid detection of free abdominal fluid, normally referred to as FAST (Focused Assessment with Sonography in Trauma). However, there is some controversy regarding its value because free abdominal fluid may be lacking in patients with abdominal organ injuries from blunt trauma. More recently, a new ultrasound technique has been developed using contrast agents. Contrast-enhanced ultrasound performs better than the non-contrast-enhanced technique for the detection of abdominal solid organ injuries and can play an important role in the prompt evaluation of patients with blunt trauma. Furthermore, contrast-enhanced ultrasound can be used in the follow-up of patients who have solid organ lesions and are managed with nonoperative treatment, avoiding radiation and iodinated contrast medium exposure.

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.

Contrast-enhanced ultrasound in non-operative management of pancreatic injury in childhood

We report a 5-year-old child with pancreatic trauma from a blunt abdominal injury that was monitored with contrast-enhanced sonography. Unenhanced US failed to demonstrate the abnormality that was recognized by CT and MRI. The injury was well demonstrated by contrast-enhanced US which was therefore used for follow-up until its healing.