Whole body 16-row multislice CT in emergency room: effects of different protocols on scanning time, image quality and radiation exposure

A vendor-agnostic, PACS integrated, and DICOM-compatible software-server pipeline for testing segmentation algorithms within the clinical radiology workflow

Background

Reproducible approaches are needed to bring AI/ML for medical image analysis closer to the bedside. Investigators wishing to shadow test cross-sectional medical imaging segmentation algorithms on new studies in real-time will benefit from simple tools that integrate PACS with on-premises image processing, allowing visualization of DICOM-compatible segmentation results and volumetric data at the radiology workstation.

Purpose

In this work, we develop and release a simple containerized and easily deployable pipeline for shadow testing of segmentation algorithms within the clinical workflow.

Methods

Our end-to-end automated pipeline has two major components- 1. A router/listener and anonymizer and an OHIF web viewer backstopped by a DCM4CHEE DICOM query/retrieve archive deployed in the virtual infrastructure of our secure hospital intranet, and 2. An on-premises single GPU workstation host for DICOM/NIfTI conversion steps, and image processing. DICOM images are visualized in OHIF along with their segmentation masks and associated volumetry measurements (in mL) using DICOM SEG and structured report (SR) elements. Since nnU-net has emerged as a widely-used out-of-the-box method for training segmentation models with state-of-the-art performance, feasibility of our pipleine is demonstrated by recording clock times for a traumatic pelvic hematoma nnU-net model.

Results

Mean total clock time from PACS send by user to completion of transfer to the DCM4CHEE query/retrieve archive was 5 min 32 s (± SD of 1 min 26 s). This compares favorably to the report turnaround times for whole-body CT exams, which often exceed 30 min, and illustrates feasibility in the clinical setting where quantitative results would be expected prior to report sign-off. Inference times accounted for most of the total clock time, ranging from 2 min 41 s to 8 min 27 s. All other virtual and on-premises host steps combined ranged from a minimum of 34 s to a maximum of 48 s.

Conclusion

The software worked seamlessly with an existing PACS and could be used for deployment of DL models within the radiology workflow for prospective testing on newly scanned patients. Once configured, the pipeline is executed through one command using a single shell script. The code is made publicly available through an open-source license at "https://github.com/vastc/," and includes a readme file providing pipeline config instructions for host names, series filter, other parameters, and citation instructions for this work.

A vendor-agnostic, PACS integrated, and DICOMcompatible software-server pipeline for testing segmentation algorithms within the clinical radiology workflow

Background

Reproducible approaches are needed to bring AI/ML for medical image analysis closer to the bedside. Investigators wishing to shadow test cross-sectional medical imaging segmentation algorithms on new studies in real-time will benefit from simple tools that integrate PACS with on-premises image processing, allowing visualization of DICOM-compatible segmentation results and volumetric data at the radiology workstation.

Purpose

In this work, we develop and release a simple containerized and easily deployable pipeline for shadow testing of segmentation algorithms within the clinical workflow.

Methods

Our end-to-end automated pipeline has two major components-1. a router/listener and anonymizer and an OHIF web viewer backstopped by a DCM4CHEE DICOM query/retrieve archive deployed in the virtual infrastructure of our secure hospital intranet, and 2. An on-premises single GPU workstation host for DICOM/NIfTI conversion steps, and image processing. DICOM images are visualized in OHIF along with their segmentation masks and associated volumetry measurements (in mL) using DICOM SEG and structured report (SR) elements. Feasibility is demonstrated by recording clock times for a traumatic pelvic hematoma cascaded nnU-net model.

Results

Mean total clock time from PACS send by user to completion of transfer to the DCM4CHEE query/retrieve archive was 5 minutes 32 seconds (+/- SD of 1 min 26 sec). This compares favorably to the report turnaround times for whole-body CT exams, which often exceed 30 minutes. Inference times accounted for most of the total clock time, ranging from 2 minutes 41 seconds to 8 minutes 27 seconds. All other virtual and on-premises host steps combined ranged from a minimum of 34 seconds to a maximum of 48 seconds.

Conclusion

The software worked seamlessly with an existing PACS and could be used for deployment of DL models within the radiology workflow for prospective testing on newly scanned patients. Once configured, the pipeline is executed through one command using a single shell script. The code is made publicly available through an open-source license at "https://github.com/vastc/", and includes a readme file providing pipeline config instructions for host names, series filter, other parameters, and citation instructions for this work.

Trauma Computed Tomography in the Modern Era: Not Always Quick and Safe

BACKGROUND

Computed tomography (CT) has emerged as the diagnostic modality of choice in trauma patients. Recent studies suggest its use in hemodynamically unstable patients is safe and potentially lifesaving; however, the incidence of adverse events (AE) during the trauma CT scanning process remains unknown.

STUDY DESIGN

Over a 6-month period at a Level 1 trauma center, data on patients undergoing trauma CT (whole-body CT (WBCT) +/- additional CT studies) were prospectively collected. All patients requiring a trauma team activation (TTA) were included. Adverse events and specific time intervals were recorded from the time of TTA notification to the time of return to the resuscitation bay from the CT suite.

RESULTS

Of the 94 consecutive patients included in the study, 47.9% experienced 1 or more AE. Median duration away from the resuscitation bay for all patients was 24 minutes. Patients with AE spent a significantly longer time away from the resuscitation bay and had longer scan times. Vasopressor support and ongoing transfusion requirement at the time of CT scanning were associated with AE.

CONCLUSION

Adverse events of varying clinical significance occur frequently in patients undergoing emergent trauma CT. A standard trauma CT protocol could improve the efficiency and safety of the scanning process.

The role of body computed tomography in hospitalized patients with obscure infection: Retrospective consecutive cohort study

OBJECTIVE

Patients with severe infection or sepsis require fast identification of the focus and prompt eradication. This study aims at investigating the role of body computed tomography (CT) and identifying outcome predictors in a general ward setting of patients with obscure infection.

METHODS

We retrospectively identified 196 consecutive body CTs acquired in 179 patients with obscure infection, i.e. severe infection or sepsis from general wards with unclear focus, over 12-months in the year 2018. Reports were extracted using a full-text search in the radiological information system (RIS) of a large university medical center. CT reports were classified according to diagnostic confidence of the reader (i.e. certain, likely, possible, no focus), and correlated with clinical and laboratory parameters. The discharge diagnosis was set as the diagnostic reference standard. Contingency tables were prepared for statistical analysis with Chi-squared test amongst other analyses and the calculation of AUC statistics.

RESULTS

In 133 out of 196 (67.9 %) body CTs from general wards with severe infection or sepsis, body CT identified an infectious focus. 90 % of the infections were located in the chest, abdomen, and genitourinary tract, in descending order. In 76.5 % (150 of 196) of examinations, CT correctly predicted the final infectious source. The positive predictive value (PPV) of a CT-detected focus was 84.2 % (95 % CI 79.0%-88.3%). A high diagnostic confidence of the reader resulted in a PPV of 96.4 % (95 % CI 87.4%-99.1%) while a low confidence resulted in a PPV of 63.3 % (95 % CI 48.2%-76.3%).

CONCLUSION

In patients with obscure infection treated in general wards, body CT detects the infectious source with a high positive predictive value. Focus detection accuracy highly depends on the diagnostic confidence of the CT reader.

Detection of fractures of hand and forearm in whole-body CT for suspected polytrauma in intubated patients

Background

The aim of this study was to evaluate the potential of whole-body CT for diagnosis of hand and forearm fractures in intubated patients with suspected polytrauma.

Methods

We performed a retrospective analysis on data collected from two trauma centres in Germany, including demographics, ISS, clinical symptoms, depiction in whole-body CT, and time to diagnosis.

Results

Out of 426 patients included in the study, 66 (15.5%) suffered a hand or forearm fracture. The total number of fractures was 132, the whole-body CT report mentioned 98 (74.2%). 16 (12,1%) fractures of 12 patients were diagnosed later than 24 h after admission. Late diagnoses of fractures of the hand occurred more often if the hand was not fully included in the CT scan field. The sensitivity of whole-body CT for cases with fractures of hand and/or forearm with full inclusion of the corresponding area in the scan field was 80.2%.

Conclusions

This study shows that whole-body CT is a valuable diagnostic tool for hand fractures in polytrauma patients. Hands should be evaluated regardless of clinical presentation in intubated patients after suspected polytrauma if they are included in the whole-body CT.

Whole-Body Computed Tomography Using Low-Dose Biphasic Injection Protocol With Adaptive Statistical Iterative Reconstruction V: Assessment of Dose Reduction and Image Quality in Trauma Patients

AIM

This study aimed to evaluate potential dose savings on a revised protocol for whole-body computed tomography and image quality after implementing Adaptive Statistical Iterative Reconstruction V (ASiR-V) algorism for trauma patients and compare it with routine protocol.

MATERIALS AND METHODS

One hundred trauma patients were classified into 2 groups using 2 different scanning protocols. Group A (n = 50; age, 32.48 ± 8.09 years) underwent routine 3-phase protocol. Group B (n = 50; age, 35.94 ± 13.57 years) underwent biphasic injection protocol including unenhanced scan for the brain and cervical spines, followed by a 1-step acquisition of the thorax, abdomen, and pelvis. The ASiR-V level was kept at 50% for all examinations, and then studies were reconstructed at 0% ASiR-V level. Radiation dose, total acquisition time, and image count were compared between groups (A and B). Two radiologists independently graded image quality and artifacts between both groups and 2 ASiR-V levels (0 and 50%).

RESULTS

The mean (±SD) dose-length product value for postcontrast scans in group A was 1602.3 ± 271.8 mGy · cm and higher when compared with group B (P < 0.001), which was 951.1 ± 359.6 mGy · cm. Biphasic injection protocol gave a dose reduction of 40.4% and reduced the total acquisition time by 11.4% and image count by 37.6%. There was no statistically significant difference between the image quality scores for both groups; however, group A scored higher grades (4.62 ± 0.56 and 4.56 ± 0.67). Similarly, the image quality scores for both ASiR-V levels in both groups were not significantly different.

CONCLUSIONS

Biphasic computed tomography protocol reduced radiation dose with maintenance of diagnostic accuracy and image quality after implementing ASiR-V algorism.

Whole body computed tomography in multi trauma patients: Review of the current literature

Many authors adopt the Selected Computed Tomography (SCT) approach of the Advanced Trauma Life Support (ATLS) for the management of multiple trauma patients. In the SCT approach, the initial physical examination is followed by conventional radiography (cervical X-ray, chest X-ray, pelvic X-ray and Focused Abdominal Sonography in Trauma (FAST)), and the computed tomography (CT) of the specific body regions if indicated. An alternative to this traditional approach is the Whole-body Computed Tomography (WBCT) protocol, which became widespread all over the world in the last two decades to minimize the rate of missed injuries and decrease the mortality rate.

According to the literature, the WBCT approach is superior to the traditional SCT approach in the time of imaging, diagnostic accuracy, and mortality rates. Conversely, WBCT increases the cancer risk due to additional irradiation. Therefore, it is recommended that the WBCT protocol should be reserved for only severe multi-trauma patients. However, further studies to define severe patients, and clinical decision criteria for WBCT are needed.

Effect of arm position, presence of medical devices, and off-centering during acquisition of scout image on automatic tube voltage selection and current modulation in pediatric chest CT

PURPOSE

To evaluate the patients' morphologic factors affecting radiation dose in pediatric chest CT.

MATERIALS AND METHODS

From November 2013 to May 2015, 315 pediatric chest CT scans were obtained using a CT scanner, and classified into 5 groups according to the patients' age. For each age group, the chest CT scans were divided into two subgroups. A cut-off value used was the 75th percentile of size-specific dose estimates (SSDE), age-specific diagnostic reference level (DRL): less than the 75th percentile of SSDE (Group A, n = 238) and greater than the 75th percentile of SSDE (Group B, n = 77). All CT scans were performed with the same protocol using automatic tube voltage selection and current modulation techniques. The morphologic factors of the patients including body mass index (BMI), arm angles, presence of medical devices in the scan field, and degree of off-centering within the CT gantry were compared between groups A and B.

RESULTS

Group B showed narrower arm angles on scout and coronal reformatted images, higher frequency of the presence of devices and higher BMI than group A (P < 0.001, P < 0.001; P = 0.018, and P < 0.001, respectively). In multivariate analysis, narrower arm angles, the presence of devices on the scout images and higher BMI were independently associated with higher SSDE (P = 0.001, P = 0.037, and P < 0.001, respectively).

CONCLUSIONS

During acquisition of the scout images, arms-down position and the presence of medical devices were associated with a high radiation dose above age-specific DRLs in pediatric chest CT, regardless of repositioning before the actual scanning. In addition, off-centering had no clinical impact on radiation dose in the routine practice.

Whole body CT versus selective radiological imaging strategy in trauma: an evidence-based clinical review

BACKGROUND

Trauma patients often present with injuries requiring resuscitation and further evaluation. Many providers advocate for whole body computed tomography (WBCT) for rapid and comprehensive diagnosis of life-threatening injuries.

OBJECTIVE

Evaluate the literature concerning mortality effect, emergency department (ED) length of stay, radiation, and incidental findings associated with WBCT.

DISCUSSION

Physicians have historically relied upon history and physical examination to diagnose life-threatening injuries in trauma. Diagnostic imaging modalities including radiographs, ultrasound, and computed tomography have demonstrated utility in injury detection. Many centers routinely utilize WBCT based on the premise this test will improve mortality. However, WBCT may increase radiation and incidental findings when used without considering pre-test probability of actionable traumatic injuries. Studies supporting WBCT are predominantly retrospective and incorporate trauma scoring systems, which have significant design weaknesses. The recent REACT-2 trial randomized trauma patients with high index of suspicion for actionable injuries to WBCT versus selective imaging and found no mortality difference. Additional prospective trials evaluating WBCT in specific trauma subgroups (e.g. polytrauma) are needed to evaluate benefit. In the interim, the available data suggests clinicians should adopt a selective imaging strategy driven by history and physical examination.

CONCLUSIONS

While observational data suggests an association between WBCT and a benefit in mortality and ED length of stay, randomized controlled data suggests no mortality benefit to this diagnostic tool. The literature would benefit from confirmatory studies of the use of WBCT in trauma sub-groups to clarify its impact on mortality for patients with specific injury patterns.

Errors in imaging of traumatic injuries

The advent of multi-detector computed tomography (MDCT) has drastically improved the outcomes of patients with multiple traumatic injuries. However, there are still diagnostic challenges to be considered. A missed or the delay of a diagnosis in trauma patients can sometimes be related to perception or other non-visual cues, while other errors are due to poor technique or poor image quality. In order to avoid any serious complications, it is important for the practicing radiologist to be cognizant of some of the most common types of errors. The objective of this article is to review the various types of errors in the evaluation of patients with multiple trauma injuries or polytrauma with MDCT.

Retrospective analysis of whole-body multislice computed tomography findings taken in trauma patients

Objectives

Using whole-body multislice computed tomography (MSCT) excessively or with irrelevant indications can be seen in many centers. The aim of this study was to analyze retrospectively the MSCT findings in trauma patients admitted to the emergency department.

Methods

Records of the patients who have applied to the emergency department due to blunt trauma in a 12 month period and whose whole body MSCT images have been taken, were evaluated using the “Nucleus Medical Information System”.

Results

The most frequent type of trauma was traffic accidents in 61.4%, falling down from the height in 22.4%, and motorcycle accidents in 11.4% of patients. Of the patients, 25.2% were discharged from the emergency, while 73.8% were hospitalized. At least one CT findings associated with trauma was present in 61.4% of our patients. Pathological findings in MSCT were most frequently detected in the head and face (35.3%) and thoracic (28.6%) regions, respectively. The most common finding in the head and face region was fractures. The most common pathological findings in the thoracic region were pulmonary contusion and rib fractures. A significant relationship was detected between trauma type and spinal MSCT result (p < 0.001). In a large percentage of the patients, MSCT findings were normal in the abdominal region and genitourinary system. Vertebral fractures were most frequently detected in the thoracolumbar region.

Conclusions

In our study, our rate of negative CT was found to be 38.6%, which is a higher ratio compared to other studies conducte on this topic.

Trauma whole-body MDCT: an assessment of image quality in conventional dual-phase and modified biphasic injection

OBJECTIVE

To compare the image quality of conventional arterial and portal venous (PV) phase multidetector CT (MDCT) with two biphasic injection protocols in polytrauma patients.

METHODS

60 consecutive patients with polytrauma underwent body 256-slice MDCT with a conventional protocol or 1 of 2 single-pass biphasic protocols: Group A, arterial (30 s) and PV (60 s) phase acquisitions; Group B, "biphasic" contrast injection with a single acquisition at 60 s; and Group C, "modified biphasic" injection with a single acquisition at a 70-s delay. Images were analyzed for arterial, venous and parenchymal attenuation profiles with regions of interest in the major arteries, veins and solid abdominal organs. A 5-point scoring system was used to assess the image quality, with 5 representing excellent arterial, venous and parenchymal opacification and <3 representing non-diagnostic opacification. In addition, the effective dose (millisieverts) was compared between the groups.

RESULTS

In 93% of patients, image quality was scored as good or excellent (≥4). All studies were of satisfactory diagnostic quality. Overall, venous and arterial attenuation profiles were comparable. Attenuation profiles in the solid abdominal viscera were significantly higher (p < 0.01) using both biphasic protocols than with arterial or PV phase of conventional protocols. Effective doses were higher in Group A.

CONCLUSION

Comparable image quality can be achieved using a biphasic i.v. contrast injection protocol with single MDCT acquisition with less radiation and reduction in acquisition time.

ADVANCES IN KNOWLEDGE

For these particular biphasic injection protocols, we have shown that image quality is comparable with a conventional protocol. This has been achieved by comparing enhanced densities of specific structures, as well as gestalt scoring by assessors, on a 256-slice MDCT.

Dose reduction in 64-row whole-body CT in multiple trauma: an optimized CT protocol with iterative image reconstruction on a gemstone-based scintillator

OBJECTIVE

Evaluation of potential dose savings by implementing adaptive statistical iterative reconstruction (ASiR) on a gemstone-based scintillator in a clinical 64-row whole-body CT (WBCT) protocol after multiple trauma.

METHODS

Dose reports of 152 WBCT scans were analysed for two 64-row multidetector CT scanners (Scanners A and B); the main scanning parameters were kept constant. ASiR and a gemstone-based scintillator were used in Scanner B, and the noise index was adjusted (head: 5.2 vs 6.0; thorax/abdomen: 29.0 vs 46.0). The scan length, CT dose index (CTDI) and dose-length product (DLP) were analysed. The estimated mean effective dose was calculated using normalized conversion factors. Student's t-test was used for statistics.

RESULTS

Both the mean CTDI (mGy) (Scanner A: 53.8 ± 2.0, 10.3 ± 2.5, 14.4 ± 3.7; Scanner B: 48.7 ± 2.2, 7.1 ± 2.3, 9.1 ± 3.6; p < 0.001, respectively) and the mean DLP (mGy cm) (Scanner A: 1318.9 ± 167.8, 509.3 ± 134.7, 848.8 ± 254.0; Scanner B: 1190.6 ± 172.6, 354.6 ± 128.3, 561.0 ± 246.7; p < 0.001, respectively) for the head, thorax and abdomen were significantly reduced with Scanner B. There was no relevant difference in scan length. The total mean effective dose (mSv) was significantly decreased with Scanner B (24.4 ± 6.0, 17.2 ± 5.8; p < 0.001).

CONCLUSION

The implementation of ASiR and a gemstone-based scintillator allows for significant dose savings in a clinical WBCT protocol.

ADVANCES IN KNOWLEDGE

Recent technical developments can significantly reduce radiation dose of WBCT in multiple trauma. Dose reductions of 10-34% can be achieved.

[Computed tomography in multiple trauma patients: technical aspects, work flow, and dose reduction]

CLINICAL/METHODICAL ISSUE

Patients with severe, life-threatening trauma require a fast and accurate clinical and imaging diagnostic workup during the first phase of trauma management.

STANDARD RADIOLOGICAL METHODS

Early whole-body computed tomography has clearly been proven to be the current standard of care of these patients.

METHODICAL INNOVATIONS

A similar imaging quality can be achieved in the multiple trauma setting compared with routine imaging especially using rapid, latest generation computed tomography (CT) scanners.

PERFORMANCE

This article encompasses a detailed view on the use of CT in patients with life-threatening trauma. A special focus is placed on radiological procedures in trauma units and on the methods for CT workup in routine cases and in challenging situations. Another focus discusses the potential of dose reduction of CT scans in multiple trauma as well as the examination of children with severe trauma.

ACHIEVEMENTS

Various studies have demonstrated that early whole-body CT positively correlates with low morbidity and mortality and is clearly superior to the use of other imaging modalities.

PRACTICAL RECOMMENDATIONS

Optimal trauma unit management means a close cooperation between trauma surgeons, anesthesiologists and radiologists, whereby the radiologist is responsible for a rapid and accurate radiological workup and the rapid communication of imaging findings. However, even in the trauma setting, aspects of patient radiation doses should be kept in mind.

Improving Outcomes in the Patient with Polytrauma: A Review of the Role of Whole-Body Computed Tomography

Whole-body computed tomography (WBCT) is used for the workup of the patient with blunt polytrauma. WBCT is associated with improved patient survival and reduces the emergency department length of stay. However, randomized studies are needed to determine whether early WBCT improves survival, to clarify which patients benefit the most, and to model the costs of this technique compared with traditional workup. Advancements in modern multidetector computed tomography technology and an improved understanding of optimal protocols have enabled one to scan the entire body and achieve adequate image quality for a comprehensive trauma assessment in a short period.

Split bolus technique in polytrauma: a prospective study on scan protocols for trauma analysis

BACKGROUND

For the evaluation of severely injured trauma patients a variety of total body computed tomography (CT) scanning protocols exist. Frequently multiple pass protocols are used. A split bolus contrast protocol can reduce the number of passes through the body, and thereby radiation exposure, in this relatively young and vitally threatened population.

PURPOSE

To evaluate three protocols for single pass total body scanning in 64-slice multidetector CT (MDCT) on optimal image quality.

MATERIAL AND METHODS

Three total body CT protocols were prospectively evaluated in three series of 10 consecutive trauma patients. In Group A unenhanced brain and cervical spine CT was followed by chest-abdomen-pelvis CT in portovenous phase after repositioning of the arms. Group B underwent brain CT followed without arm repositioning by a one-volume contrast CT from skull base to the pubic symphysis. Group C was identical to Group A, but the torso was scanned with a split bolus technique. Three radiologists independently evaluated protocol quality scores (5-point Likert scale), parenchymal and vascular enhancement and artifacts.

RESULTS

Overall image quality was good (4.10) in Group A, more than satisfactory (3.38) in Group B, and nearly excellent (4.75) in Group C (P < 0.001). Interfering artifacts were mostly reported in Group B in the liver and spleen.

CONCLUSION

In single pass total body CT scanning a split bolus technique reached the highest overall image quality compared to conventional total body CT and one-volume contrast CT.

Systematic review: effect of whole-body computed tomography on mortality in trauma patients

BACKGROUND

The initial diagnostic evaluation and management of trauma patients is mainly based on Advanced Trauma Life Support (ATLS) guidelines worldwide. Based on ATLS principles, conventional diagnostics such as conventional radiography (CR) and focused abdominal sonography in trauma (FAST) should precede selective use of CT. Whole-body CT (WBCT) is highly accurate and allows detection of life threatening injuries with good sensitivity and specificity. WBCT is faster than conventional diagnostics and saves more time in management of trauma patients. This study aims to review studies investigating the effect of WBCT on mortality in trauma patients.

METHODS

Literatures were found by searching keywords in Medline, PubMed and Cochrane library. The relevant articles were selected by two independent reviewers based on title, abstract and introduction sections. Full-texts of selected articles were reviewed and those investigating effect of WBCT on mortality in trauma patients were included.

RESULTS

Searching the keywords in Medline and PubMed resulted in 178 and 167 articles, respectively. Nine studies met the inclusion criteria and were reviewed. These included 8 retrospective and 1 prospective cohort studies. Mortality was measured as mortality rate or standardised mortality ratio (SMR) in the included studies.

CONCLUSIONS

Unlike previous systematic reviews, this review indicates that use of WBCT in blunt trauma patients is associated with reduced overall mortality rate and that WBCT can potentially improve the probability of survival in haemodynamically stable and unstable blunt trauma patients. High quality RCTs are required to describe a causal relationship between WBCT and mortality in trauma patients.

Specific Radiological Findings of Traumatic Gastrointestinal Tract Injuries in Patients with Blunt Chest and Abdominal Trauma

Gastrointestinal hollow viscus injury after blunt chest and abdominal trauma is uncommon and complicates 0.6%-1.2% of all cases of trauma. Early recognition of such injuries significantly decreases morbidity and mortality. Since physical examination is not accurate in detecting such injuries, contrast-enhanced computed tomography has been the mainstay for diagnosis in many emergency departments. This pictorial essay aims to review the incidence, mechanisms, and signs of gastrointestinal hollow viscus injuries in the setting of blunt chest and abdominal trauma.

Whole-body CT-based imaging algorithm for multiple trauma patients: radiation dose and time to diagnosis

OBJECTIVE

To determine the number of imaging examinations, radiation dose and the time to complete trauma-related imaging in multiple trauma patients before and after introduction of whole-body CT (WBCT) into early trauma care.

METHODS

120 consecutive patients before and 120 patients after introduction of WBCT into the trauma algorithm of the University Hospital Zurich were compared regarding the number and type of CT, radiography, focused assessment with sonography for trauma (FAST), additional CT examinations (defined as CT of the same body regions after radiography and/or FAST) and the time to complete trauma-related imaging.

RESULTS

In the WBCT cohort, significantly more patients underwent CT of the head, neck, chest and abdomen (p < 0.001) than in the non-WBCT cohort, whereas the number of radiographic examinations of the cervical spine, chest and pelvis and of FAST examinations were significantly lower (p < 0.001). There were no significant differences between cohorts regarding the number of radiographic examinations of the upper (p = 0.56) and lower extremities (p = 0.30). We found significantly higher effective doses in the WBCT (29.5 mSv) than in the non-WBCT cohort (15.9 mSv; p < 0.001), but fewer additional CT examinations for completing the work-up were needed in the WBCT cohort (p < 0.001). The time to complete trauma-related imaging was significantly shorter in the WBCT (12 min) than in the non-WBCT cohort (75 min; p < 0.001).

CONCLUSION

Including WBCT in the initial work-up of trauma patients results in higher radiation doses, but fewer additional CT examinations are needed, and the time for completing trauma-related imaging is shorter.

ADVANCES IN KNOWLEDGE

WBCT in trauma patients is associated with a high radiation dose of 29.5 mSv.

Blunt cerebrovascular injury screening guidelines: what are we willing to miss?

BACKGROUND

Blunt cerebrovascular injury (BCVI) is reported to occur in approximately 2% of blunt trauma patients, with a stroke rate of up to 20%. Guidelines for BCVI screening are based on clinical and radiographic findings. We hypothesized that liberal screening of the neck vasculature, as part of initial computed tomographic (CT) imaging in blunt trauma patients with significant mechanisms of injury, identifies BCVI that may go undetected.

METHODS

As per protocol, patients at risk for significant injuries undergo a noncontrast head CT scan followed by a multislice CT scan (40-slice or 64-slice) incorporating an intravenous contrast-enhanced pass from the circle of Willis through the pelvis (whole-body CT [WBCT] scan). The trauma registry was retrospectively reviewed, and all patients with BCVI from 2009 to 2012 were analyzed. Patients undergoing WBCT scan were then identified, and records were reviewed for BCVI indicators (skull base fracture, cervical spine injury, displaced facial fracture, mandible fracture, Glasgow Coma Scale score ≤ 8, flexion mechanism, hard signs of neck vascular injury, or focal neurologic deficit).

RESULTS

Of 16,026 patients evaluated during the study period, 256 (1.6%) were diagnosed with BCVI. The population consisted of 185 patients with suspected BCVI after WBCT scan. One hundred twenty-nine patients (70%) had at least one indicator for BCVI screening, while 56 (30%) had no radiographic or clinical risk factors; 48 of the 56 patients underwent confirmatory CT angiography of the neck within 71 hours of initial WBCT scan, with 35 patients having 45 injuries.

CONCLUSION

More liberalized screening for BCVI during initial CT imaging in trauma patients clinically judged to have sufficient mechanism is warranted. Using current BCVI screening guidelines leads to missed BCVI and risk of stroke.

LEVEL OF EVIDENCE

Diagnostic study, level III.

Errors in imaging assessment of polytrauma patients

Although the use of multidetector computed tomography (MDCT) has increased the diagnostic quality by reducing the number of missed diagnoses in polytraumatized patients, errors remain a common phenomenon in emergency room setting. MDCT errors, contributing more commonly to missed or delayed diagnoses in polytrauma patients, are diagnostic errors commonly related to perceptual errors or to nonvisual errors. However, in some cases, misdiagnoses can be attributed to technical and methodological errors leading to incomplete or poor-quality imaging. Knowledge of common patterns of error is the most effective way to avoid future errors. The purpose of this article is to highlight the most frequent types of diagnostic errors in evaluating with MDCT of polytrauma patients.

Early computed tomography scanning in multisystem trauma: The evidence

The utility of computed tomography as a radiological investigation following multisystem trauma is already well established in current practice. This article examines the existing evidence and rationale behind the use of early computed tomography scanning in the management of the multisystem trauma patient, with a particular emphasis on the use of ‘whole body’ computed tomography scanning as a component of their initial management in the Emergency Department.

The use of computed tomography has been shown to be superior to plain radiography for the detection of injuries in important body regions including the spine, thorax, abdomen and pelvis. Computed tomography scan of the head and cervical spine is also well established as the first investigation of choice for significant traumatic brain injury. The potential benefits of whole body computed tomography include reduced time to diagnosis and intervention, as well as significant improvements in clinical outcome and survival. Concerns regarding a whole body computed tomography approach relate to the increased ionising radiation dosage that patients will be exposed to, and perceived risks of the secondary transfer and scanning room environment itself. Potential barriers to the use of whole body computed tomography are also explored and discussed.

This article also presents a proposed clinical algorithm derived from the results of a recent Delphi study into whole body computed tomography following blunt multitrauma, along with conclusions and recommendations from the subject matter panel review process.

Whole body imaging in the diagnosis of blunt trauma, ionizing radiation hazards and residual risk

Ever since the introduction of radiographic imaging, its utility in identifying injuries has been well documented and was incorporated in the workup of injured patients during advanced trauma life support algorithms [American College of Surgeons, 8th ed. Chicago, 2008]. More recently, computerized tomography (CT) has been shown to be more sensitive than radiography in the diagnosis of injury. Due to the increased use of CT scanning, concerns were raised regarding the associated exposure to ionizing radiation [N Engl J Med 357:2277-2284, 2007]. During the last several years, a significant amount of research has been published on this topic, most of it being incorporated in the BEIR VII Phase 2 report, published by the National Research Council of the National Academies [National Academy of Sciences, Washington DC, 2006]. The current review will analyze the scientific basis for the concerns over the ionizing radiation associated with the use of CT scanning and will examine the accuracy of the typical advanced trauma life support work-up for diagnosis of injuries.

Systematic review and meta-analysis of immediate total-body computed tomography compared with selective radiological imaging of injured patients

BACKGROUND

The aim of this review was to assess the value of immediate total-body computed tomography (CT) during the primary survey of injured patients compared with conventional radiographic imaging supplemented with selective CT.

METHODS

A systematic search of the literature was performed in MEDLINE, Embase, Web of Science and Cochrane Library databases. Reports were eligible if they contained original data comparing immediate total-body CT with conventional imaging supplemented with selective CT in injured patients. The main outcomes of interest were overall mortality and time in the emergency room (ER).

RESULTS

Four studies were included describing a total of 5470 patients; one study provided 4621 patients (84.5 per cent). All four studies were non-randomized cohort studies with retrospective data collection. Mortality was reported in three studies. Absolute mortality rates differed substantially between studies, but within studies mortality rates were comparable between immediate total-body CT and conventional imaging strategies (pooled odds ratio 0.91, 95 per cent confidence interval 0.79 to 1.05). Time in the ER was described in three studies, and in two was significantly shorter in patients who underwent immediate total-body CT: 70 versus 104 min (P = 0.025) and 47 versus 82 min (P < 0.001) respectively.

CONCLUSION

This review showed differences in time in the ER in favour of immediate total-body CT during the primary trauma survey compared with conventional radiographic imaging supplemented with selective CT. There were no differences in mortality. The substantial reduction in time in the ER is a promising feature of immediate total-body CT but well designed and larger randomized studies are needed to see how this will translate into clinical outcomes.

Benefit of the Vittel criteria to determine the need for whole body scanning in a severe trauma patient

OBJECTIVE

To evaluate the use of the Vittel criteria in addition to a clinical examination to determine the need for a whole body scan (WBS) in a severe trauma patient.

MATERIALS AND METHODS

Between December 2008 and November 2009, 339 severe trauma patients with at least one Vittel criterion were prospectively evaluated with a WBS. The following data were collected: the Vittel criteria present, circumstances of the accident, traumatic injury on the WBS, and irradiation. The original intent to prescribe a computed tomography (CT) scan (whole body or a targeted region), based solely on clinical signs, was specified.

RESULTS

Injuries were diagnosed in 55.75% of the WBS (n=189). The most common Vittel criteria were "global assessment" (n=266), "thrown, run over" (n=116), and "ejected from vehicle" (n=94). The multivariate analysis used the following as independent criteria for predicting severe traumatic injury on the WBS: Glasgow score less than 13, penetrating trauma, and colloid resuscitation greater than 11. Based solely on clinical factors, 164 patients would not have had any scan or (only) a targeted scan. In that case, 15% of the severe injuries would have been missed.

CONCLUSION

Using the Vittel criteria to determine the need for a WBS in a severe trauma patient makes it possible to find serious injuries not suspected on the clinical examination, but at the cost of an increased number of normal scans.

A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2)

BACKGROUND

Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its usage is currently becoming common practice in several trauma centers. However, literature provides limited evidence whether immediate total-body CT leads to better clinical outcome then conventional radiographic imaging supplemented with selective CT scanning in trauma patients. The aim of the REACT-2 trial is to determine the value of immediate total-body CT scanning in trauma patients.

METHODS/DESIGN

The REACT-2 trial is an international, multicenter randomized clinical trial. All participating trauma centers have a multi-slice CT scanner located in the trauma room or at the Emergency Department (ED). All adult, non-pregnant, severely injured trauma patients according to predefined criteria will be included. Patients in whom direct scanning will hamper necessary cardiopulmonary resuscitation or who require an immediate operation because of imminent death (both as judged by the trauma team leader) are excluded. Randomization will be computer assisted. The intervention group will receive a contrast-enhanced total-body CT scan (head to pelvis) during the primary survey. The control group will be evaluated according to local conventional trauma imaging protocols (based on ATLS guidelines) supplemented with selective CT scanning. Primary outcome will be in-hospital mortality. Secondary outcomes are differences in mortality and morbidity during the first year post trauma, several trauma work-up time intervals, radiation exposure, general health and quality of life at 6 and 12 months post trauma and cost-effectiveness.

DISCUSSION

The REACT-2 trial is a multicenter randomized clinical trial that will provide evidence on the value of immediate total-body CT scanning during the primary survey of severely injured trauma patients. If immediate total-body CT scanning is found to be the best imaging strategy in severely injured trauma patients it could replace conventional imaging supplemented with CT in this specific group.

TRIAL REGISTRATION

ClinicalTrials.gov: (NCT01523626).

The role of early multislice computed tomography in major trauma

Whole-body multislice spiral computed tomography (MSCT) has become a very important dignostic tool in the management of patients with multiple injuries. Many reports exist which demonstrate the feasibility and the benefit when using whole-body MSCT in the early phase of in-hospital management of trauma patients. Even in hemodynamically instable patients (except cardiac arrest), whole-body MSCT can be used and is a safe diagnostic procedure. While the diagnostic superiority of multislice computed tomography is proven for different organ regions (e.g. head/brain, chest, abdomen, pelvis and spine), its use as a single whole-body scan is still part of an ongoing discussion. Especially concerns about radiation exposure are the reason for uncertainty about when using whole-body trauma scan. Predefined scan protocols and individual positioning of patients may help to keep radiation dose as minimal as possible. To justify higher radiation dose, the indication must be chosen appropriately. Therefore, the use of a sensitive and specific triage scheme seems to be reasonable. Overscanning patients with minor trauma needs to be avoided, while the benefit for patients with severe multiple injuries is obvious.

CT imaging of blunt chest trauma

BACKGROUND: Thoracic injury overall is the third most common cause of trauma following injury to the head and extremities. Thoracic trauma has a high morbidity and mortality, accounting for approximately 25% of trauma-related deaths, second only to head trauma. More than 70% of cases of blunt thoracic trauma are due to motor vehicle collisions, with the remainder caused by falls or blows from blunt objects. METHODS: The mechanisms of injury, spectrum of abnormalities and radiological findings encountered in blunt thoracic trauma are categorised into injuries of the pleural space (pneumothorax, hemothorax), the lungs (pulmonary contusion, laceration and herniation), the airways (tracheobronchial lacerations, Macklin effect), the oesophagus, the heart, the aorta, the diaphragm and the chest wall (rib, scapular, sternal fractures and sternoclavicular dislocations). The possible coexistence of multiple types of injury in a single patient is stressed, and therefore systematic exclusion after thorough investigation of all types of injury is warranted. RESULTS: The superiority of CT over chest radiography in diagnosing chest trauma is well documented. Moreover, with the advent of MDCT the imaging time for trauma patients has been significantly reduced to several seconds, allowing more time for appropriate post-diagnosis care. CONCLUSION: High-quality multiplanar and volumetric reformatted CT images greatly improve the detection of injuries and enhance the understanding of mechanisms of trauma-related abnormalities.

Spiral head CT in the evaluation of acute intracranial pathology: a pictorial essay

The purpose of this pictorial essay is to review the benefits of spiral head computed tomography (CT) with routine multiplanar reformations in the evaluation of acute intracranial pathology. This technique is particularly useful in trauma patients for detection of skull base or calvarial fractures, thin tentorial subdural hematomas, or for more specific characterization of intracranial hemorrhage. The benefits of multiplanar reformations have been described for a variety of other diagnoses in the chest, abdomen, extremities, and spine, and their routine use continues to grow with the widespread availability of multi-slice CT scanners. In this article, we describe spiral head CT technique with multiplanar reformations as an alternative to the routinely used sequential technique. Subtle findings and lesions aligned predominantly in the axial plane can often be visualized to better advantage with multiplanar reformations. We also address technical factors for optimizing spiral technique.

Violence-related facial trauma: analysis of multidetector computed tomography findings of 727 patients

OBJECTIVES

The multidetector CT (MDCT) findings of facial trauma in victims of interpersonal violence were assessed.

METHODS

All MDCT requests for suspected facial injury during a 62 month period were retrieved; 727 cases met the inclusion criteria. Images were interpreted by two researchers by consensus.

RESULTS

Of the 727 patients (aged 15-86 years old, mean 37), 583 (80.2%) were male and 144 (19.8%) female. Of all the patients, 74% had a fracture, and of these 44% had multiple non-contiguous fractures.

CONCLUSIONS

Violence is a very common cause of facial injury. Nasal and orbital fractures predominate. Males are more often involved; they are younger, sustain fractures more often and significantly more often present with high-energy fracture patterns. LeFort fractures are often unilateral or asymmetrical, and are frequently accompanied by other, clinically significant fractures. Up to 25% of patients with fractures do not have paranasal sinus effusions.

Essential pre-treatment imaging examinations in patients with endoscopically-diagnosed early gastric cancer

Background

There have been no reports discussing which imaging procedures are truly necessary before treatment of endoscopically-diagnosed early gastric cancer (eEGC). The aim of this pilot study was to show which imaging examinations are essential to select indicated treatment or appropriate strategy in patients with eEGC.

Methods

In 140 consecutive patients (95 men, 45 women; age, 66.4 +/- 11.3 years [mean +/- standard deviation], range, 33-90) with eEGC which were diagnosed during two years, the pre-treatment results of ultrasonography (US) and contrast-enhanced computed tomography (CT) of the abdomen, barium enema (BE) and chest radiography (CR) were retrospectively reviewed. Useful findings that might affect indication or strategy were evaluated.

Results

US demonstrated useful findings in 13 of 140 patients (9.3%): biliary tract stones (n = 11) and other malignant tumors (n = 2). Only one useful finding was demonstrated on CT (pancreatic intraductal papillary mucinous tumor) but not on US (0.7%; 95% confidential interval [CI], 2.1%). BE demonstrated colorectal carcinomas in six patients and polyps in 10 patients, altering treatment strategy (11.4%; 95%CI, 6.1-16.7%). Of these, only two colorectal carcinomas were detected on CT. CR showed three relevant findings (2.1%): pulmonary carcinoma (n = 1) and cardiomegaly (n = 2). Seventy-nine patients (56%) were treated surgically and 56 patients were treated by endoscopic intervention. The remaining five patients received no treatment due to various reasons.

Conclusions

US, BE and CR may be essential as pre-treatment imaging examinations because they occasionally detect findings which affect treatment indication and strategy, although abdominal contrast-enhanced CT rarely provide additional information.

Trauma management incorporating focused assessment with computed tomography in trauma (FACTT) - potential effect on survival

Background

Immediate recognition of life-threatening conditions and injuries is the key to trauma management. To date, the impact of focused assessment with computed tomography in trauma (FACTT) has not been formally assessed. We aimed to find out whether the concept of using FACTT during primary trauma survey has a negative or positive effect on survival.

Methods

In a retrospective, multicentre study, we compared our time management and probability of survival (Ps) in major trauma patients who received FACTT during trauma resuscitation with the trauma registry of the German Trauma Society (DGU). FACTT is defined as whole-body computed tomography (WBCT) during primary trauma survey. We determined the probability of survival according to the Trauma and Injury Severity Score (TRISS), the Revised Injury Severity Classification score (RISC) and the standardized mortality ratio (SMR).

Results

We analysed 4.817 patients from the DGU database from 2002 until 2004, 160 (3.3%) were from our trauma centre at the Ludwig-Maximilians-University (LMU) and 4.657 (96.7%) from the DGU group. 73.2% were male with a mean age of 42.5 years, a mean ISS of 29.8. 96.2% had suffered from blunt trauma. Time from admission to FAST (focused assessment with sonography for trauma)(4.3 vs. 8.7 min), chest x-ray (8.1 vs. 16.0 min) and whole-body CT (20.7 vs. 36.6 min) was shorter at the LMU compared to the other trauma centres (p < 0.001). SMR calculated by TRISS was 0.74 (CI95% 0.40-1.08) for the LMU (p = 0.24) and 0.92 (CI95% 0.84-1.01) for the DGU group (p = 0.10). RISC methodology revealed a SMR of 0.69 (95%CI 0.47-0.92) for the LMU (p = 0.043) and 1.00 (95%CI 0.94-1.06) for the DGU group (p = 0.88).

Conclusion

Trauma management incorporating FACTT enhances a rapid response to life-threatening problems and enables a comprehensive assessment of the severity of each relevant injury. Due to its speed and accuracy, FACTT during primary trauma survey supports rapid decision-making and may increase survival.