[Structured radiologic diagnosis in polytrauma]

[Importance of multidetector CT imaging in multiple trauma]

CLINICAL/METHODICAL ISSUE

Diagnostic imaging of complex multiple trauma remains a challenge for any department providing modern emergency radiology (ER) service. An early and comprehensive approach for ER imaging is crucial for a priority-oriented and timely therapy concept with the aim of identifying potentially life-threatening injuries early and initiating appropriate treatment.

STANDARD RADIOLOGICAL METHODS

The basic diagnostic approach still consists of focused ultrasound using focused assessment with sonography for trauma (FAST) and conventional radiography (CR), usually limited to a single supine chest x-ray for triaging patients undergoing immediate operations.

METHODICAL INNOVATIONS

Multidetector computed tomography (MDCT) has become established as early whole body CT (WBCT) as the undisputable diagnostic method. The detection rate of injuries by WBCT is outstanding and it improves the probability of survival by 20-25% compared with all other previous methods. At the same time, the spatial and temporal resolution of MDCT was improved resulting in considerably shortened examination times but WBCT is still associated with a significant radiation exposure, even in the acute single use setting. Using modern scanner and dose reduction technology, including iterative reconstruction, a dose reduction of up to 40% could be achieved. The substantial number of images in WBCT is another challenge; images must be processed priority-oriented, read and transferred to the picture archiving and communications system (PACS). For rapid diagnosis, volume image reading (VIR) offers additional options to keep the diagnostic process on time.

ACHIEVEMENTS/PRACTICAL RECOMMENDATIONS

Modern WBCT after multiple trauma is performed early, comprehensively and personalized so that WBCT improves the probability of survival by 20-25%.

Retrospective analysis of incidental non-trauma associated findings in severely injured patients identified by whole-body spiral CT scans

BACKGROUND

Whole-body Computed Tomography (CT) scan today is considered a crucial imaging technique in the diagnostic work-up of polytrauma patients implicating a potential survival benefit. Apart from prompt identification of life threatening injuries this imaging technique provides an additional benefit by diagnosing incidental non-trauma associated medical diseases. These incidental findings might be also life threatening and warrant urgent therapy. The downside of whole-body CT is a relatively high radiation exposure that might result in an increased life time cancer risk. The aim of this study was to investigate the frequency and type of non trauma associated incidental medical findings in relation to patient age and potential clinical relevance.

METHODS

Between January 1(st) 2011 and December 15th 2012, a total of 704 trauma patients were referred to our hospital's emergency room that triggered trauma room alarm according to our trauma mechanism criteria. Of these 534 (75.8%) received a whole-body CT according to our dedicated multiple trauma protocol. Incidental Findings (IF) were assigned in three groups according to their clinical relevance. Category 1: IF with high medical relevance (urgent life threatening conditions, unless treated) needing early investigations and intervention prior to or shortly after hospital discharge. Category 2: IF with intermediate or low medical relevance, warranting further investigations. Category 3: IF without clinical relevance.

RESULTS

Overall 231 IFs (43.3%) were identified, 36 (6.7%) patients had IFs with a high clinical relevance, 48 (9.0%) with a moderate or minor clinical relevance and 147 (27.5%) with no clinical relevance. The distribution of incidental findings with high or moderate relevance according to age showed an incidence of 2.6%, 6.6% and 8.8% for patients younger than 40 years, 40 to 60 years and older than 60 years, respectively.

CONCLUSION

Whole-body CT scans of trauma patients demonstrate a high rate of incidental findings. Potentially life-threatening, medical findings were found in approximately every 15th patient, predominantly aged over 40 years and presenting with minor to moderate injuries and an Injury Severity Score (ISS) of 10 or less.

[Modern imaging techniques for liver trauma]

Involvement of the liver is one of the most common injuries in addition to those of the pancreas following blunt force abdominal trauma. Due to the even now high mortality radiological imaging must provide a rapid, definitive and exact assessment of the extent of the damage. Despite conflicting study results ultrasound has become established as a rapid and relatively simple method in emergency room treatment and is irreplaceable for initial orientation diagnostics. The use of contrast medium-assisted examinations promises to be an advantage for diagnostics in the secondary phase. Due to the high sensitivity and specificity modern multidetector computed tomography is the most effective examination modality for the detection of liver damage and hepatobiliary complications and plays a central role in non-operative management following abdominal trauma. Shorter and shorter scan times even allow the examination of metastable patients and a rapid assessment even of large body volumes.

Introduction of a treatment algorithm can improve the early management of emergency patients in the resuscitation room

INTRODUCTION

Successful management of emergency patients with multiple trauma in the hospital resuscitation room depends on the immediate diagnosis and rapid treatment of the most life-threatening injuries. In order to reduce the time spent in the resuscitation room, an in-hospital algorithm was developed in an interdisciplinary team approach with respect to local structures. The aim of the study was to analyse whether this algorithm affects the interval between hospital admission and the completion of diagnostic procedures and the start of life-saving interventions. Moreover, in-hospital mortality was investigated before and after the algorithm was introduced.

MATERIAL AND METHODS

In this prospective study, all consecutive trauma patients in the resuscitation room were investigated before (group I, 01/04-10/04) and after (group II, 01/05-11/05) introduction of the algorithm. The times between hospital admission and the end of the diagnostic procedures (ultrasound [sono], chest X-ray [CF], and cranial computed tomography [CCT]), and between hospital admission and the start of life-saving interventions were registered and in-hospital mortality analysed.

RESULTS

In the study period, 170 patients in group I and 199 patients in group II were investigated. Injury severity score (ISS) were comparable between the two groups. The intervals between admission and completion of diagnostic procedures were significantly lower after the algorithm was introduced (mean+/-S.D.): sono (11 +/- 10 min versus 7 +/- 6 min, p < 0.05), CF (21 +/- 12 min versus 12 +/- 9 min, p < 0.01), and CCT (55 +/- 27 min versus 32 +/- 14 min, p < 0.01). Moreover, the interval to the start of life-saving interventions was significantly shorter (126 +/- 90 min versus 51 +/- 20 min, p < 0.01). After introducing the algorithm, in-hospital mortality was reduced significantly from 33.3% to 16.7% (p < 0.05) in the most severely injured patients (ISS>or=25).

CONCLUSION

The introduction of an algorithm for early management of emergency patients significantly reduced the time spent in the resuscitation room. The periods to completion of sono, CF, and CCT, respectively, and the start of life-saving interventions were significantly shorter after introduction of the algorithm. Moreover, introduction of the algorithm reduced mortality in the most severely injured patients. Although further investigations are needed to evaluate the effects of the Heidelberg treatment algorithm in terms of outcome and mortality, the time reduction in the resuscitation room seems to be beneficial.

[Current concepts of polytrauma management: from ATLS to "damage control"]

In recent years, the implementation of standardized protocols for polytrauma management has led to a significant improvement in trauma care as well as to a decrease in post-traumatic morbidity and mortality. As such, the "Advanced Trauma Life Support" (ATLS) protocol of the American College of Surgeons for the acute management of severely injured patients has been established as a gold standard in most European countries since the 1990s. Continuative concepts to the ATLS program include the "Definitive Surgical Trauma Care" (DSTC) algorithm and the concept of "damage control" surgery for polytraumatized patients with immediate life-threatening injuries. These phase-oriented therapeutic strategies appraise the injured patient of the whole extent of the sustained injuries and are in sharp contrast to previous modalities of "early total care" which advocate immediate definitive surgical intervention. The approach of "damage control" surgery takes into account the influence of systemic post-traumatic inflammatory and metabolic reactions of the organism and is aimed at reducing both the primary and the secondary, delayed, mortality in severely injured patients. The present paper provides an overview of the current state of management algorithms for polytrauma patients, with a focus on the standard concepts of ATLS and "damage control".

Radiologische Interventionen bei polytraumatisierten Patienten

The most frequent cause of mortality during the first 4 h following severe trauma is uncontrollable hemorrhage from large arteries and parenchymal organs, whereas traumatic injuries of the heart and aorta are responsible for sudden death occurring at the accident site. It is therefore mandatory to diagnose and treat these injuries rapidly. Multislice spiral computed tomography is a highly useful imaging modality for severely injured patients. In this group of patients, various interventional procedures such as embolisation, stenting and temporary balloon occlusion may contribute to saving lives. In ruptures of the aorta and major arteries, stenting and temporary balloon occlusion may prevent exsanguination. Transcatheter embolisation is useful in hemorrhage from visceral organs, arteriovenous fistulas and secondary onset hemorrhage.

Der Würzburger Schockraumalgorithmus

BACKGROUND

The purpose of this study was to show the practicability of a new algorithm in the management of polytraumatized patients based on Advanced Trauma Live Support (ATLS) and using mobile whole body multislice CT (MMDCT) as the primary imaging system.

PATIENTS AND METHODS

A series of 120 trauma patients referred to the Würzburg University Hospital Trauma Emergency Room were categorized into suspected polytrauma and suspected non-polytrauma groups. The polytraumatized patients were investigated using the Würzburg polytrauma-algorithm including whole body multislice CT with a 16-row-scanner. The algorithm is described. The time for the diagnostic procedure was measured and compared with data from the Trauma Registry of the German Society of Trauma Surgery.

RESULTS

From 120 patients 78 (66%) underwent whole body CT. The diagnostic procedure was quick with significant advantages especially for cranial and trunk diagnostics.

CONCLUSION

The Würzburg polytrauma algorithm worked well. There was excellent cooperation within the interdisciplinary leading team consisting of anaesthesiologists, surgeons, and radiologists. The principles of ATLS could be respected. Mobile whole body multislice CT was an effective tool in the diagnostic evaluation of polytrauma patients.

[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.

Value of Multiplanar Reformations (MPR) in Multidetector CT (MDCT) of Acute Vertebral Fractures

OBJECTIVE

To determine the value of multiplanar reformations (MPRs) in multidetector computed tomography (MDCT) diagnosis of acute vertebral fractures and to assess the necessity to read the whole set of transverse images.

METHODS

Retrospectively, 56 MDCT of 55 patients with acute vertebral fractures were included. The images were analyzed by two radiologists in a consensus procedure. First, the diagnosis was made exclusively from sagittal and coronal MPRs; secondly, the transverse images were analyzed with knowledge of the MPRs. Diagnostic accuracy is given as percentage. Image amounts were compared using the Wilcoxon test.

RESULTS

In 244 vertebral bodies, all 70 fractured vertebrae were diagnosed on reviewing MPRs only. There were no false positive cases. In 2/70 fractures, the anatomically exact diagnosis was complemented by reading the transverse images. Forty-two of 43 unstable fractures were diagnosed correctly on MPRs only. With preference of MPR reading, the total number of images to be analyzed could be reduced significantly (P < 0.01).

CONCLUSION

Reading of MPRs alone is a feasible approach for correct assessment of vertebral fractures and classifying them into stable/unstable, if MPRs are done properly. Transverse images must be analyzed in complex fractures or uncertain findings.

First experiences with multidetector CT in traumatized children

INTRODUCTION

The aim of this study was to describe and discuss first experiences with multidetector CT (MDCT) in the assessment of traumatized children.

MATERIAL AND METHODS

Since the implementation of a MDCT scanner in April 2002, 85 children (31 girls, 54 boys with a mean age of 9.2 years) consecutively underwent MDCT (Siemens, Erlangen, Germany) with different protocols depending on age, weight, trauma mechanism and clinical presentation. In all patients in whom pathology was suspected, multiplanar reformations (MPR) in coronal and or sagittal orientation was performed. Examinations were evaluated by two radiologists retrospectively and in consensus.

RESULTS

In 55 (65%) children, a MDCT solely of the head was performed, in 46 there was no pathology found. In six (7%), head and facial bones were scanned. Head and abdomen was examined in two (2%), in two (2%) the abdomen only and in one (1%) the pelvis solely. Scans of the spine were obtained in seven (8%) children. A thorax and abdomen examination only was obtained in one (1%) child each. In 11 (13%) children, a polytrauma protocol was performed. In all patients, the time of examination did not exceed 17 min, including setup time. All children survived at the writing of this report.

CONCLUSION

MDCT was promising in the management of traumatized children and seems to shorten the necessary time to reach diagnosis and to initiate life-saving treatment.

Radiological emergency room management with emphasis on multidetector-row CT

Trauma is the fifth leading cause of death after disease of the cardiovascular system, malignomas and disease of the respiratory and digestive system. The management of severely injured patients, including radiological imaging, is a matter of ongoing development. In particular, as for the imaging modalities, multidetector-row CT represents a substantial refinement in the diagnostic work-up of multitrauma patients. Sufficient therapy within the first hour after trauma increases the patient's chances for survival significantly. Thus, therapeutic procedures and diagnostic evaluation have to be concomitant events, performed by a multidisciplinary team, namely trauma surgeon, anesthesiologist and, last but not least, radiologist. The increased performance of multidetector-row CT leads to increased spatial resolution, which is a prerequisite for sophisticated two- and three-dimensional postprocessing. The increased volume coverage speed allows for comprehensive whole-body CT at still high levels of spatial resolution, resulting in significant spare of time which influences patient's survival. Using this technique conventional imaging such as plane film or angiography may be omitted.

Three-dimensional volume rendering of multidetector-row CT data: applicable for emergency radiology

Multidetector-row computed tomography (MD-CT) not only creates new opportunities but also challenges for medical imaging. Isotropic imaging allows in-depth views into anatomy and disease but the concomitant dramatic increase of image data requires new approaches to visualize, analyze and store CT data. The common diagnostic reviewing process slice by slice becomes more and more time consuming as the number of slice increases, while on the other hand CT volume data sets could be used for three-dimensional visualization. These techniques allow for comprehensive interpretation of extent of fracture, amount of dislocation and fragmentation in a three-dimensional highly detailed setting. Further more, using minimal invasive techniques like CT angiography, new opportunities for fast emergency room patient's work up arise. But the most common application is still trauma of the musculoskeletal system as well as face and head. The following is a brief review of recent literature on volume rendering technique and some exemplary applications for the emergency room.