Blunt abdominal trauma: should US be used to detect both free fluid and organ injuries?

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.

Pediatric blunt splenic trauma: a comprehensive review

Abdominal trauma is a leading cause of death in children older than 1 year of age. The spleen is the most common organ injured following blunt abdominal trauma. Pediatric trauma patients present unique clinical challenges as compared to adults, including different mechanisms of injury, physiologic responses, and indications for operative versus nonoperative management. Splenic salvage techniques and nonoperative approaches are preferred to splenectomy in order to decrease perioperative risks, transfusion needs, duration/cost of hospitalization, and risk of overwhelming postsplenectomy infection. Early and accurate detection of splenic injury is critical in both adults and children; however, while imaging findings guide management in adults, hemodynamic stability is the primary determinant in pediatric patients. After initial diagnosis, the primary role of imaging in pediatric patients is to determine the level and duration of care. We present a comprehensive literature review regarding the mechanism of injury, imaging, management, and complications of traumatic splenic injury in pediatric patients. Multiple patients are presented with an emphasis on the American Association for the Surgery of Trauma organ injury grading system. Clinical practice guidelines from the American Pediatric Surgical Association are discussed and compared with our experience at a large community hospital, with recommendations for future practice guidelines.

Findings and limitations of focused ultrasound as a possible screening test in stable adult patients with blunt abdominal trauma: a Greek study

Our objective is to underline the place of FAST (focus assessment by sonography for trauma) ultrasonography (US) in the investigation of blunt abdominal trauma. We retrospectively examined the ultrasound findings in 1,999 haemodynamically stable adult patients. These people were admitted to the emergency room (ER) for possible blunt abdominal trauma. All were stable at admission and a FAST ultrasound examination was made. Initial findings were compared with the clinical course after at least 24 h of observation time and CT results. Among the 1,999 US examinations, abnormalities were found in 109 (5.5%) cases. Among them, 102 had free peritoneal fluid, and in 58 examinations, ruptures, lacerations or haematomas were demonstrated. Despite its limitations, such as in cases involving uncooperative patients, excessive bowel gas, obesity and empty bladder, the FAST technique seems to be an accurate method to evaluate the possibility of abdominal blunt trauma in stable patients. Because of the high negative predictive value of the FAST technique in stable patients with blunt abdominal trauma, we recommend that a stable patient with negative ultrasound results at admission remain under close observation for at least 12 or preferably 24 h before being discharged.

Abdominal trauma--sensitivity and specificity of postmortem noncontrast imaging findings compared with autopsy findings

OBJECTIVE

The aim of the study was to determine the sensitivity and specificity for typical abdominal injuries after major blunt trauma in postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI).

MATERIAL

Thirty-four cases of accidental death underwent postmortem pre-autopsy MSCT and MRI. The imaging findings were correlated with the autopsy findings.

RESULTS

Sensitivity and specificity for liver injury in computed tomography (CT) alone were 53% and 84%. In MRI, a sensitivity of 58% and a specificity of 46% were found. CT and MRI together (when either one was positive, liver-injury was considered) had a sensitivity of 73% and a specificity of 63%. For major liver lacerations (grades II-VI) a slightly higher sensitivity of 81% and a better specificity of 100% were noted. CT and MRI together showed a sensitivity of 50% for injuries of the spleen, specificity was 89%. CT and MRI together had a sensitivity of only 25% for trauma of the kidney, but a specificity of 100%.

CONCLUSION

A lot of cases with small organ injuries (such as superficial liver-laceration) seemed that could not be found by MSCT or by MRI, leading to a rather low sensitivity. Nevertheless, most of the life-threatening liver injuries could be detected, which is essential in forensic pathology.

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.

Ultrasound enhanced with sulphur-hexafluoride-filled microbubbles agent (SonoVue) in the follow-up of mild liver and spleen trauma

PURPOSE

This study assessed the role of contrast-enhanced ultrasound (CEUS) in the follow-up of patients with a diagnosis of traumatic liver or spleen lesions.

MATERIALS AND METHODS

Between April 2006 and February 2008, 18 patients (13 males and five females, age range 8-42 years) with blunt abdominal trauma were evaluated with computed tomography (CT) and CEUS at the emergency department of our institution. Seven were diagnosed as surgical emergencies and were excluded from the study. The remaining 11 were treated conservatively and were monitored with CEUS at variable time intervals, depending on their clinical needs.

RESULTS

CEUS confirmed lesion sites identified on presentation and allowed us to follow all phases of the repair process until complete resolution.

CONCLUSIONS

The conservative management of abdominal lesions in both adults and children is increasingly widespread but requires accurate follow-up over time. As a noninvasive, versatile, easy to perform and repeatable technique with a low rate of adverse reactions, CEUS is ideally suited for this purpose and allowed us to reduce the number of CT scans, especially in the follow-up of young patients.

Imaging children with abdominal trauma

OBJECTIVE

Trauma is a leading cause of morbidity and mortality in children. The abdomen is the second most common site of injury. This article discusses abdominal trauma in children.

CONCLUSION

The clinical evaluation of children with potential blunt abdominal injury presents a challenging task. Therefore, imaging plays an essential role in the evaluation of such children.

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.

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.

[Evidence-based diagnosis of abdominal trauma]

Abdominal trauma is a common cause of death particularly in patients up to 40 years of age. In order to reduce mortality a rapid radiologic diagnosis is essential. At present, sonography plays a role only in the evaluation of minor trauma and as a "focused assessment with sonography for trauma" (FAST) to clarify free intraperitoneal fluid immediately on admittance in severely injured patients. However, computed tomography has proven to be a potent tool for the triage of patients with abdominal trauma, because, based on the results of the CT scan, patients can be referred for laparotomy or safely classified for "wait and see" treatment. Therapeutic decisions are largely based on injury severity scores and the radiologist must be familiar with them as well as with the associated therapeutic consequences.

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.

Diagnostic peritoneal lavage and ultrasonography for blunt abdominal trauma: attitudes and training of current general surgical trainees

OBJECTIVE

It has been suggested that diagnostic peritoneal lavage is now obsolete in UK hospitals with access to either skilled ultrasonography or emergency physician or surgeon-performed focused abdominal sonography in trauma. Diagnostic peritoneal lavage continues to be advocated and taught on Advanced Trauma Life Support courses. The aim of this study was to evaluate the experiences and attitudes of general-surgery trainees in one UK training region towards diagnostic peritoneal lavage and focused abdominal sonography in trauma in managing blunt abdominal trauma.

METHODS

An anonymous postal piloted questionnaire was sent to all 66 general surgery specialist trainees in one UK training region between January and March 2005.

RESULTS

Out of 40 replies to the questionnaire (response rate 61%), 53% and 38% of surgical trainees had either never performed or never observed a diagnostic peritoneal lavage during their training. Thirteen trainees (33%) felt diagnostic peritoneal lavage to be obsolete and would never contemplate using it; 15 trainees (37%) might consider using diagnostic peritoneal lavage if computed tomography or ultrasonography were unavailable. Ten trainees (25%) felt that diagnostic peritoneal lavage had been superseded by computed tomography. Only 12 trainees (30%) had worked in a UK hospital with access to facilities for focused abdominal sonography in trauma and only seven trainees (18%) had received any training or experience in focused abdominal sonography in trauma.

CONCLUSIONS

Surgical trainees in one UK training region lack skills in both diagnostic peritoneal lavage and focused abdominal sonography in trauma for managing blunt abdominal trauma and are therefore reliant upon the availability of prompt, skilled radiological assistance or emergency physician-provided focused abdominal sonography in trauma.

Multislice computed tomography in blunt abdominal trauma

Blunt abdominal trauma is a frequent finding in patients with multiple trauma, and is associated with significant morbidity and mortality. Multislice computed tomography (MSCT), allowing for multiplanar reconstructions and three-dimensional images, has become the imaging modality of choice for these patients. MSCT is indicated in all haemodynamically stable patients with suspected blunt abdominal trauma. A `focussed CT' algorithm, as recommended by the Advanced Trauma Life Support (ATLS®) program, may be useful for patients with isolated abdominal trauma who are conscious and cooperative. For unconscious patients with or without multiple trauma `unfocussed' whole-body MSCT algorithms should be used, as these lead to earlier as well as more accurate diagnosis. MSCT allows for rapid diagnosis of abdominal and retroperitoneal injuries and for grading of solid organ injuries. Active haemorrhage may be detected with accuracy similar to angiography. Even bowel, diaphragmatic and bladder injuries, where CT used to miss a significant number of injuries, can be diagnosed with high accuracy by the new generation of MSCT scanners.

Are diagnostic peritoneal lavage or focused abdominal sonography for trauma safe screening investigations for hemodynamically stable patients after blunt abdominal trauma? A review of the literature

BACKGROUND

Assessment of patients in the emergency department who sustain blunt abdominal trauma represents a significant diagnostic challenge. Computed tomography (CT) is increasingly used as the principal investigation for these patients. A sensitive screening test could safely reduce the use of CT.

OBJECTIVES

To appraise the evidence supporting the use of diagnostic peritoneal lavage and focused abdominal sonography for trauma as screening tests in the emergency department to reduce the use of CT in the initial assessment of patients sustaining blunt abdominal trauma.

METHODS

A search of high-quality evidence resources was performed, followed by a hand search of the bibliographies of all relevant articles.

RESULTS

Altogether, 55 articles were found during the initial search, of which 23 were relevant. An additional 11 were found by hand searching. Six relevant original research articles were found.

CONCLUSION

Screening diagnostic peritoneal lavage and selective CT is a safe diagnostic strategy for the investigation of blunt abdominal trauma. Further research is needed to determine the role of focused abdominal sonography for trauma scanning in diagnostic protocols.

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.

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.

The Utility of Sonography for the Triage of Blunt Abdominal Trauma Patients to Exploratory Laparotomy

OBJECTIVE

The purpose of this study was to assess the utility of focused abdominal sonography for trauma (FAST) in the triage of hypotensive and normotensive blunt abdominal trauma patients to exploratory laparotomy.

MATERIALS AND METHODS

Data entered in a trauma registry database were retrospectively reviewed and were correlated with medical records, radiology reports, and surgical laparotomy reports. In the setting of blunt abdominal trauma, hypotensive patients were compared with normotensive patients who underwent FAST.

RESULTS

During the 6-year study period, 4,029 patients with blunt abdominal trauma underwent sonography, 122 of whom were hypotensive on arrival and underwent FAST. Of 87 hypotensive patients with positive findings on FAST, 69 (79%) were taken directly to exploratory laparotomy without the need for CT. In predicting the need for therapeutic laparotomy in hypotensive patients, the sensitivity of FAST was 85%, specificity was 60%, and accuracy was 77%. Of the 3,907 normotensive patients, 3,584 had negative FAST findings, whereas 323 had positive FAST findings. In normotensive patients, the sensitivity of FAST was 85%, specificity was 96%, and accuracy was 96%. In the combined patient population (all hypotensive and normotensive patients), 4,029 patients with blunt abdominal trauma underwent sonography: 3,619 had negative and 410 had positive FAST findings. In all patients regardless of blood pressure, the sensitivity of FAST was 85%, specificity was 96%, and accuracy was 95%.

CONCLUSION

Hypotensive patients screened in the emergency department with positive FAST findings may be triaged directly to therapeutic laparotomy, depending on the results of the sonography examination, without the need for CT.

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.

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

OBJECTIVE

The objective of our study was to prospectively compare the diagnostic value of sonography and contrast-enhanced sonography with CT for the detection of solid organ injuries in blunt abdominal trauma patients.

SUBJECTS AND METHODS

Sonography, contrast-enhanced sonography, and CT were performed to assess possible abdominal organ injuries in 69 nonconsecutive hemodynamically stable patients with blunt abdominal trauma and a strong clinical suspicion of abdominal lesions. Sonography and contrast-enhanced sonography findings were compared with CT findings, the reference standard technique.

RESULTS

Thirty-two patients had 35 abdominal injuries on CT (10 kidney or adrenal lesions, seven liver lesions, 17 spleen lesions, and one retroperitoneal hematoma). Sixteen lesions were detected on sonography, and 32 were seen on contrast-enhanced sonography. The sensitivity and specificity of sonography were 45.7% and 91.8%, respectively, and the positive and negative predictive values were 84.2% and 64.1%, respectively. Contrast-enhanced sonography had a sensitivity of 91.4%, a specificity of 100%, and positive and negative predictive values of 100% and 92.5%, respectively.

CONCLUSION

Contrast-enhanced sonography was found to be more sensitive than sonography and almost as sensitive as CT in the detection of traumatic abdominal solid organ injuries. It can therefore be proposed as a useful tool in the assessment of blunt abdominal trauma.

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.

Development of an accelerated MSCT protocol (Triage MSCT) for mass casualty incidents: comparison to MSCT for single-trauma patients

During multiple casualty incidents (MCI) emergency radiology departments have to deal with a large number of patients with suspected severe trauma within a short period of time. The aim of this study was to develop a suitable accelerated multislice computed tomography (MSCT) protocol to increase patient throughput for this kind of emergency situation. We presumed a scenario of 15 patients being admitted to the trauma service with suspicion of severe injuries after a MCI over a period of 2 h. An accelerated Triage MSCT protocol was developed and evaluated for MSCT scanner productivity (patients per hour) and time (minutes) needed for a total MSCT body workup using an anthropomorphic phantom. In addition, time (minutes) for transfer and preparation was measured. These timeframes were compared to a control group consisting of 144 single patients with multiple trauma undergoing standard MSCT according to our trauma room protocol. All MSCT studies were conducted using a 4-detector row scanner. (1) For the study group (Triage MSCT), average time for patient transfer and preparation was 2.9 min (2.5-4.3 min), mean CT examination time was 2.1 min (1.7-2.4 min); image reconstruction took 4.0 min (3.3-4.3 min). Total time in scanner room was 8.9 min (7.7-11.3 min), resulting in a maximal productivity of 6.7 patients per hour. Image transfer to the digital picture archive and communication system archive was completed after an average 9.5 min (8.9-10.8 min). (2) For the control group (single casualty MSCT), the mean time for patient transfer and preparation was 20.4 min (9.0-39.2 min), mean examination time was 6.0 min (3.1-11.3 min). Times for image reconstructions were not recorded in the patient series. Mean total time in scanner room was 25.3 min (11.0-72.4 min), resulting in a patient throughput of 2.4 patients per hour. MSCT has potential to serve as a powerful tool in triage of multiple casualty patients. The introduction of a Triage MSCT scanning protocol resulted in an increase of patient throughput per hour by a factor of almost 3.

Prehospital ultrasound imaging improves management of abdominal trauma

BACKGROUND

Blunt abdominal trauma with intra-abdominal bleeding is often underdiagnosed or even overlooked at trauma scenes. The purpose of this prospective, multicentre study was to compare the accuracy of physical examination and prehospital focused abdominal sonography for trauma (PFAST) to detect abdominal bleeding.

METHODS

Six rescue centres took part in the study from December 2002 to December 2003, including 230 patients with suspected abdominal injury. The accuracy of physical examination at the scene and PFAST were compared. Later examinations in the emergency department (ultrasonography and/or computed tomography) were used as the reference standard.

RESULTS

The complete protocol and follow-up was obtained in 202 patients. The sensitivity, specificity and accuracy of PFAST were 93 per cent, 99 per cent and 99 per cent, respectively, compared with 93 per cent, 52 per cent and 57 per cent for physical examination at the scene. Scanning with PFAST occurred a mean(s.d.) 35(13) min earlier than ultrasound in the emergency department. Abdominal bleeding was detected in 14 per cent of patients. Using PFAST led to a change in either prehospital therapy or management in 30 per cent of patients, and a change to admitting hospital in 22 per cent.

CONCLUSION

In this study, PFAST was a useful and reliable diagnostic tool when used as part of surgical triage at the trauma scene.

Screening US and CT for blunt abdominal trauma: a retrospective study

OBJECTIVE

To assess the accuracy of screening US and CT in patients with blunt abdominal trauma admitted to the trauma centre of our General Hospital.

MATERIALS AND METHOD

The abdominal US reports of 864 primary trauma patients (139 with major and 725 with minor injuries) and 162 CT reports of a subgroup of the same subjects (64 with major and 98 with minor injuries) were reviewed and compared to the best available reference standard. The accuracy of screening US was assessed by evaluating its overall ability to distinguish negative from positive cases by showing at least one of the lesions documented by the reference standard and its specific ability to depict all lesions; CT reports were evaluated only for the method's performance in depicting all lesions.

RESULTS

Screening US exhibited a satisfactory overall ability to distinguish negative from positive patients (91.5% sensitivity and 97.5% specificity in major trauma patients versus 73.3% sensitivity and 98.1% specificity in the minor trauma group) and a satisfactory specific ability to depict all injuries in major trauma patients. In minor trauma cases sensitivity was satisfactory for free fluid but unsatisfactory for organ injuries. Of the 21/864 false negative reports (5 in patients with major and 16 in cases with minor traumas), only one affected patient management, a major trauma case, by delaying an emergency laparotomy. The performance of CT in detecting each single lesion was predictably excellent in both patient groups.

CONCLUSION

Its satisfactory accuracy for major trauma suggests that US could be employed not only to screen cases for emergency laparotomy but also as an alternative to CT. However, since major traumatic injuries generally carry an imperative indication for CT, especially as regards neurological, thoracic and skeletal evaluation, US should be employed to perform a prompt preliminary examination using a simplified technique in the emergency room simultaneously with resuscitation.

Moderne Diagnostik des Bauchtraumas

In case of suspected intra-abdominal injury, fast transport of the patient to a suitable hospital is of high priority. The initial clinical examination aims at identifying patients with potentially life-threatening bleeding that require emergency surgery. In patients with penetrating trauma, laparoscopy is favoured to exclude suspected perforation of the peritoneum. If a peritoneal perforation is identified, exploratory laparotomy is recommended to exclude or treat lacerations of the hollow viscus. Although clinical examination should be performed its sensitivity and specificity of up to 82% and 45%, respectively, are not sufficient as the sole screening method. For the further diagnostic workup, diagnostic peritoneal lavage has been completely replaced by abdominal ultrasound examination in Germany and many other countries. Focussing not only on the detection of free abdominal fluid but also searching for parenchymal organ lesions and performing repeated examinations increases accuracy up to 96%, with specificity of 99.8% and sensitivity of 72.1%. Computed abdominal tomography with a helical scanner with and without intravenous contrast media is currently the gold standard of imaging techniques to identify traumatic abdominal injuries. A sensitivity of 97.2% and specificity of 94.7% can be achieved. False negative findings must be expected with hollow organ injuries. Serial clinical and ultrasound examinations as well as lab testing in conjunction with repeated CT may help to identify such lesions. Increased intra-abdominal pressure (IAP) with consecutive abdominal compartment syndrome and multiple organ dysfunction is a delayed complication from conditions such as severe intra-abdominal bleeding, major bleeding from pelvic ring fractures, and profuse fluid resuscitation. The IAP should be measured routinely in patients at risk, and decompression laparotomy may be indicated with pressures of higher than 20 mmHg.

Ultrasound detection of blunt urological trauma: a 6-year study

The objective of this study was to assess the utility of emergency ultrasonography in the detection of blunt urological injury. A retrospective review was conducted of all consecutive emergency blunt trauma ultrasonograms (US) obtained at a level I trauma centre from January 1995 to January 2001. Among the 4320 emergency ultrasonograms performed, 596 patients (14%) had intraabdominal injury and, of these, 99 patients (17%) had urological injuries. The sensitivity of ultrasound for all urological injuries was 67%, and specificity was 99.8%. For isolated urological injuries, sensitivity and specificity were 55.6 and 99.8%, respectively. Ultrasound was most accurate in the detection of grade III renal injuries, identifying 14/15 (93%), and 13 underwent laparotomy. For isolated urological injuries, 15 of 25 (60%) patients with a true-positive US underwent laparotomy compared to 3 of 20 (15%) with a false-negative US. Isolated urological injury was significantly associated with an ultrasonographic pattern of free fluid in the left upper quadrant and the left pericolic gutter (odds ratio=55.1; P<0.001), followed by isolated fluid in the left pericolic gutter (odds ratio=8.6; P=0.04). Although emergency ultrasonography is useful in the triage of patients with blunt urological trauma, it may miss significant urological injury requiring further intervention. As most renal injuries may be managed non-operatively, further studies such as contrast-enhanced CT or angiography should be obtained in the stable patient with suspected blunt urological injury.

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

OBJECTIVE

The purpose of this study was to report our initial experience in the assessment of liver trauma with real-time contrast-enhanced sonography (CES).

METHODS

From January 2000 to December 2003, there were 431 hemodynamically stable patients evaluated with sonography for blunt abdominal trauma. Among these patients, 87 were selected to undergo second-level imaging, consisting of CES and computed tomographic (CT) evaluation. Indications for further assessment were baseline sonographic findings positive for liver injury, baseline sonographic findings positive for injury to other abdominal parenchyma, baseline sonographic findings positive for free fluid only, baseline sonographic findings indeterminate, and baseline sonographic findings negative with persistent clinical or laboratory suspicion.

RESULTS

There were 23 hepatic lesions shown by CT in 21 patients. Peritoneal or retroperitoneal fluid was identified in 19 of 21 positive cases by all 3 imaging modalities. Liver injury was found in 15 patients on sonography and in 19 on CES. Contrast-enhanced sonography compared better than unenhanced sonography with the criterion standard for related injury conspicuity, injury size, completeness of injury extension, and involvement of the liver capsule. Both CES and CT showed intrahepatic contrast material pooling in 2 cases. All patients with false-negative sonographic or CES findings recovered uneventfully.

CONCLUSIONS

Contrast-enhanced sonography is an effective tool in the evaluation of blunt hepatic trauma, being more sensitive than baseline sonography and correlating better than baseline sonography with CT findings. In institutions where sonography is regarded as the initial procedure to screen patients with trauma, this technique may increase its effectiveness. In addition, CES may be valuable in the follow-up of patients with conservatively treated liver trauma.

[Shock trauma room diagnosis: initial diagnosis after blunt abdominal trauma. A review of the literature]

OBJECTIVE

Blunt abdominal trauma is most common in the polytraumatized patient and beside neurocranial trauma one major determinant of early death in these patients. Therefore, immediate recognition of an abdominal injury is of life-saving importance.

METHODS

Clinical trials were systematically collected (Medline, Cochrane and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system).

RESULTS

Clinical examination is not reliable for evaluation of abdominal injury. Abdominal ultrasound, especially if only focusing on free fluid (FAST) is not sensitive enough. Today, CT-scan of the abdomen is the gold-standard in diagnosing abdominal injury. Diagnostic Peritoneal Lavage (DPL) has a high sensitivity but in our region only is used in exceptional cases. The patient with continuing hemodynamical instability after abdominal trauma and evidence of free intraperitonial fluid has to undergo laparotomy.

CONCLUSION

After blunt abdominal trauma, initially ultrasound investigation should be performed in the emergency room. This should not only focus on free intraabdominal fluid but also on organ lesions. Regardless of the findings from ultrasound or clinical examination, the hemodynamically stable patient should undergo a CT-scan of the abdomen in order to proof or exclude an abdominal injury.

Reevaluation of ultrasonography for solid-organ injury in blunt abdominal trauma

OBJECTIVE

To reevaluate the usefulness of ultrasonography for detecting and classifying solid-organ injuries from blunt abdominal trauma by comparing ultrasonography with computed tomography (CT) and laparotomy.

METHODS

Six hundred four patients with blunt abdominal trauma were examined by both B-mode ultrasonography and CT for a study period of 14 years. The ultrasonographic examiners were divided into 2 groups depending on their experience with ultrasonography. The ultrasonographic results were then compared with CT and surgical findings. This was a retrospective study.

RESULTS

In 198 patients, solid-organ injuries were identified on CT, laparotomy, or both. Sensitivity values in group A (experts) were 87.5% for hepatic injuries, 85.4% for splenic injuries, 77.6% for renal injuries, and 44.4% for pancreatic injuries. Sensitivity values in group B were 46.2% for hepatic injuries, 50.0% for splenic injuries, and 44.1% for renal injuries. The detection rates in group A were 80% to 100% for different types of hepatic injuries except superficial injuries (20%) and 70% to 100% for different types of splenic injuries. The detection rates for renal parenchymal and pancreatic duct injuries were 53.3% and 80%, respectively. The detection rates for injuries requiring intervention were 86.1% in group A and 66.7% in group B.

CONCLUSIONS

The sensitivity of ultrasonography with the use of CT and surgical findings as reference standards decreased compared with our prior study. However, ultrasonography was found to enable experienced examiners to detect and classify parenchymal injuries efficiently, despite disadvantages in detecting superficial and vascular injuries. Ultrasonography should be used to explore not only free fluid but also solid-organ injuries.

Blunt Abdominal Trauma:Does the Use of a Second-Generation Sonographic Contrast Agent Help to Detect Solid Organ Injuries?

OBJECTIVE

The objective of our study was to prospectively evaluate whether a second-generation sonography contrast agent (SonoVue) can improve the conspicuity of solid organ injuries (liver; spleen; or kidney, including adrenal glands) in patients with blunt abdominal trauma.

SUBJECTS AND METHODS

Two hundred ten consecutive hemodynamically stable trauma patients underwent both abdominal sonography and CT at admission. The presence of solid organ injuries and the quality of sonography examinations were recorded. Patients with false-negative sonography findings for solid organ injuries in comparison with CT results underwent control sonography. If a solid organ injury was still undetectable, contrast-enhanced sonography was performed. Findings of admission, control, and contrast-enhanced sonograms were compared with CT results for their ability to depict solid organ injuries. Contrast-enhanced sonography was also performed in patients in whom a vascular injury (pseudoaneurysm) was shown on admission or control CT.

RESULTS

CT findings were positive for 88 solid organ injuries in 71 (34%) of the 210 patients. Admission, control, and contrast-enhanced sonograms had a detection rate for solid organ injury of 40% (35/88), 57% (50/88), and 80% (70/88), respectively. The improvement in the detection rate between control and contrast-enhanced sonography was statistically significant (p = 0.001). After exclusion of low-quality examinations, contrast-enhanced sonography still missed 18% of solid organ injuries. Five vascular liver (n = 1) and spleen (n = 4) injuries (pseudoaneurysms) were detected on CT; all were visible on contrast-enhanced sonography.

CONCLUSION

Contrast-enhanced sonography misses a large percentage of solid organ injuries and cannot be recommended to replace CT in the triage of hemodynamically stable trauma patients. However, contrast-enhanced sonography could play a role in the detection of pseudoaneurysms.

The use of sonography versus computed tomography in the triage of blunt abdominal trauma: the European perspective

The management of the trauma-emergency patient has become an important political and economic issue and one of the major challenges of the industrialized countries. In Europe ultrasonography is always part of the basic work-up, following physical examination, whereas computed tomography (CT) remains a second-line investigation. Injury prevalence, radiation dose exposure, practicability, and costs are relevant considerations in our emergency departments, where we have a growing number of patients seeking medical attention. The radiologist's task is to decide which imaging modality is most appropriate after the clinical context has been taken into consideration. The clinical value of CT is unquestioned; what is questionable is only its systematic use. With the growing demand for trauma care, screening ultrasonography can lower the number of inappropriate CT examinations.

Controversies in emergency radiology. CT versus ultrasound in the evaluation of blunt abdominal trauma

There has been controversy regarding ultrasonography (US) versus CT in blunt abdominal trauma (BAT). Each modality has its strengths and weaknesses. US is fast and allows resuscitative efforts to proceed while the patient is being scanned. However, the sensitivity of US is inferior to that of CT, and there is user variability. CT is better at determining the extent, type, and grade of injury, resulting in a more tailored therapeutic plan and safe conservative management of many patients. However, CT involves ionizing radiation, cannot be performed portably, and requires only visual monitoring while scanning. Given each modality's strengths and weaknesses we conclude that CT is the preferred examination when the BAT patient is stable or moderately stable, enough to be taken to CT. If a BAT patient is unstable, US is beneficial in screening for certain injuries or large hemoperitoneum prior to an exploratory laparotomy.

Emergency ultrasound in trauma patients

US will be used more frequently in the future for the evaluation of traumatized patients. Previously,the main focus of the sonographic examination was for the detection of free fluid. Unstable patients with free fluid often can be triaged to the operation room without further imaging tests. In patients who are more stable or in whom US results are negative, CT is required. Based on recent studies, sonography has a sensitivity rate of approximately 40% in direct detection of solid organ injuries. In the future, however, with the use of contrast-enhanced agents, sonography may more reliably detect solid organ injuries. Within the chest, US has been shown to be helpful in detecting pleural effusions and may be useful in detecting pericardial effusions. US has been shown to be sensitive in detecting pneumothoraces in traumatized patients.