Revised protocol for whole-body CT for multi-trauma patients applying triphasic injection followed by a single-pass scan on a 64-MDCT

Does delayed phase imaging in CT angiography provide additional information in patients with suspected active bleeding?

PURPOSE

We hypothesize that delayed phase imaging does not provide additional diagnostic information in patients who undergo multi-phasic CTA for suspected active bleeding.

METHODS

Data on patients who underwent multiphasic CTA (pre-contrast, arterial, porto-venous, and delayed phases) for suspected acute bleed were retrospectively collected between January 2019 and November 2021. CTA images were reviewed by a general radiologist, an interventional radiologist, and a body imaging radiologist independently. Each reader evaluated if delayed phase images provided additional information that would change the final impression of the CTA report. Additional information regarding bleeding location, time needed for delayed image acquisition, and radiation exposure were also obtained.

RESULTS

A total of 104 patients with CTAs were analyzed with an average age of 58 years ± 22. Studies rated with absent additional findings on delayed images were 102 (98.1%) by the interventional radiologist, 101 (97.1%) by the body imaging radiologist, and 100 (96.1%) by the general radiologist with percent agreement of 96.15% (kappa 0.54, p < 0.001). All the findings were characterized as unlikely to be clinically significant. Mean time added to complete a delayed phase images was 3.61 ± 3.4 min. The average CT dose length product (DLP) for the total exam was 3621.78 ± 2129.57 mGy.cm with delayed acquisition adding a mean DLP of 847.75 ± 508.8 mGy.cm.

CONCLUSION

Delayed phase imaging does not provide significant additional diagnostic information in evaluating patients with suspected active bleeding but is associated with increased examination time and radiation exposure.

Interrater Agreement of CT Grading of Blunt Splenic Injuries: Does the AAST Grading Need to Be Reimagined?

Introduction: The Revised Organ Injury Scale (OIS) of the American Association for Surgery of Trauma (AAST) is the most widely accepted classification of splenic trauma. The objective of this study was to evaluate inter-rater agreement for CT grading of blunt splenic injuries. Methods: CT scans in adult patients with splenic injuries at a level 1 trauma centre were independently graded by 5 fellowship trained abdominal radiologists using the AAST OIS for splenic injuries - 2018 revision. The inter-rater agreement for AAST CT injury score, as well as low-grade (IIII) versus high-grade (IV-V) splenic injury was assessed. Disagreement in two key clinical scenarios (no injury versus injury, and high versus low grade) were qualitatively reviewed to identify possible sources of disagreement. Results: A total of 610 examinations were included. The inter-rater absolute agreement was low (Fleiss kappa statistic 0.38, P < 0.001), but improved when comparing agreement between low and high grade injuries (Fleiss kappa statistic of 0.77, P < .001). There were 34 cases (5.6%) of minimum two-rater disagreement about no injury vs injury (AAST grade ≥ I). There were 46 cases (7.5%) of minimum two-rater disagreement of low grade (AAST grade I-III) versus high grade (AAST grade IV-V) injuries. Likely sources of disagreement were interpretation of clefts versus lacerations, peri-splenic fluid versus subcapsular hematoma, application of adding multiple low grade injuries to higher grade injuries, and identification of subtle vascular injuries. Conclusion: There is low absolute agreement in grading of splenic injuries using the existing AAST OIS for splenic injuries.

Imaging of penetrating vascular trauma of the body and extremities secondary to ballistic and stab wounds

In the United States, gunshot wounds (GSWs) have become a critical public health concern with substantial annual morbidity, disability, and mortality. Vascular injuries associated with GSW may pose a clinical challenge to the physicians in the emergency department. Patients demonstrating hard signs require immediate intervention, whereas patients with soft signs can undergo further diagnostic testing for better injury delineation. Although digital subtraction angiography is the gold standard modality to assess vascular injuries, non-invasive techniques such as Doppler ultrasound, computed tomography angiography, and magnetic resonance angiography have evolved as appropriate alternatives. This article discusses penetrating bodily vascular injuries, specifically ballistic and stab wounds, and the corresponding radiological presentations.

Retrospective Cohort Study of Frequency and Patterns of Orbital Injuries on Whole-Body CT with Maxillofacial Multi-Slice CT

Background: High-impact trauma frequently leads to injuries of the orbit, but literature focusing on the viscerocranium rather than the neurocranium is underrepresented. Methods: Retrospective cohort study (2006–2014) at an urban level 1 trauma center assessing the frequency and typical patterns of orbital injuries on whole-body computed tomography (WBCT) with maxillofacial multi-slice CT (MSCT) after severe trauma. (1) Screening of consecutive WBCT cases for dedicated maxillofacial MSCT. (2) Examination by two independent experts’ radiologists for (peri-/)orbital injuries. (3) Case review for trauma mechanisms. Results: 1061 WBCT were included revealing 250 (23.6%) patients with orbital injuries. Less than one-quarter (23.3%) of patients showed osseous and 9.5% showed soft tissue injuries. Combined osseous and soft tissue lesions were present in 39.2% of orbital injuries, isolated soft tissue injuries were rare. Single- or two-wall fractures of the orbit were prevalent, and the orbital floor was affected in 67% of fractures. Dislocated extraocular muscles (44.6%), deformation of the ocular globe (23.8%), and elongation of the optic nerve (12.9%) were the most frequently soft tissue findings. Vascular trauma was suspected in 15.8% of patients. Conclusions: Orbital trauma was confirmed in 23.6% of cases with suspected facial injuries after severe trauma. Concomitant soft tissue injuries should be excluded explicitly in cases with orbital fractures to prevent loss of vision or ocular motility.

European Society of Emergency Radiology: guideline on radiological polytrauma imaging and service (short version)

BACKGROUND

Although some national recommendations for the role of radiology in a polytrauma service exist, there are no European guidelines to date. Additionally, for many interdisciplinary guidelines, radiology tends to be under-represented. These factors motivated the European Society of Emergency Radiology (ESER) to develop radiologically-centred polytrauma guidelines.

RESULTS

Evidence-based decisions were made on 68 individual aspects of polytrauma imaging at two ESER consensus conferences. For severely injured patients, whole-body CT (WBCT) has been shown to significantly reduce mortality when compared to targeted, selective CT. However, this advantage must be balanced against the radiation risk of performing more WBCTs, especially in less severely injured patients. For this reason, we recommend a second lower dose WBCT protocol as an alternative in certain clinical scenarios. The ESER Guideline on Radiological Polytrauma Imaging and Service is published in two versions: a full version (download from the ESER homepage, https://www.eser-society.org ) and a short version also covering all recommendations (this article).

CONCLUSIONS

Once a patient has been accurately classified as polytrauma, each institution should be able to choose from at least two WBCT protocols. One protocol should be optimised regarding time and precision, and is already used by most institutions (variant A). The second protocol should be dose reduced and used for clinically stable and oriented patients who nonetheless require a CT because the history suggests possible serious injury (variant B). Reading, interpretation and communication of the report should be structured clinically following the ABCDE format, i.e. diagnose first what kills first.

Is Blush on CT Scan in Patients With Pelvic Fracture Associated With Embolization Rates and Outcomes?

INTRODUCTION

In trauma patients with pelvic fractures, computed tomography (CT) scans are a critical tool to evaluate life-threatening hemorrhage. Contrast extravasation, or "blush", on CT may be a sign of bleeding, prompting a consult for angiography and possible embolization. However, the utility of blush on CT is controversial. We sought to evaluate our experience with patients who sustained pelvic fractures and had blush on CT.

METHOD

A retrospective review was performed for all patients with blunt pelvic fractures between January 1, 2017 and December 31, 2018. Demographic, clinical, radiographic, and injury data were obtained. Comparison of mortality, hospital length of stay (LOS), and intensive care unit (ICU) LOS was performed for 3 subgroups: angio versus no angio; embo versus no embo; prophylactic embo versus therapeutic embo. We also calculated the sensitivity, specify, positive predictive value (PPV), and negative predictive value (NPV) of CT blush to predict the need for embolization.

RESULTS

889 patients were found to have a blunt pelvic fracture. 51 patients had blush on CT scan. 29 (56.9%) underwent angiography. 17 (58.6%) of these 29 patients were found to have extravasation and were embolized. 12 patients had an angio with no extravasation, and 6 of these patients (50%) underwent prophylactic embolization. No significant difference was found for hospital LOS, ICU LOS, or mortality in our 3 groups. Sensitivity, specificity, PPV, and NPV for CT blush were 74%, 96%, 33%, 99%, respectively.

CONCLUSION

Patients with active extravasation undergoing embolization had similar outcomes to patients without active extravasation. Blush on CT scan had low sensitivity and low PPV but high specificity and high NPV. Future studies need to include careful attention to the CT protocol utilized as well as patient selection.

Minimal Aortic Injury: Mechanisms, Imaging Manifestations, Natural History, and Management

Over the last 2 decades, increased depiction of minimal aortic injury (MAI) in the evaluation of patients who have sustained trauma has mirrored the increased utilization and improved resolution of multidetector CT. MAI represents a mild form of blunt traumatic aortic injury (BTAI) that usually resolves or stabilizes with pharmacologic management. The traditional imaging manifestation of MAI is a subcentimeter round, triangular, or linear aortic filling defect attached to an aortic wall, representing a small intimal flap or thrombus consistent with grade I injury according to the Society for Vascular Surgery (SVS). Small intramural hematoma (SVS grade II injury) without external aortic contour deformity is included in the MAI spectrum in several BTAI classifications on the basis of its favorable outcome. Although higher SVS grades of injury generally call for endovascular repair, there is growing literature supporting conservative management for small pseudoaneurysms (SVS grade III) and large intimal flaps (>1 cm, unclassified by the SVS), hinting toward possible future inclusion of these entities in the MAI spectrum. Injury progression of MAI is rare, with endovascular aortic repair reserved for these patients as well as patients for whom medical treatment cannot be implemented. No consensus on the predetermined frequency and duration of multidetector CT follow-up exists, but it is common practice to perform a repeat CT examination shortly after the initial diagnosis. The authors review the evolving definition, pathophysiology, and natural history of MAI, present the primary and secondary imaging findings and diagnostic pitfalls, and discuss the current management options for MAI. Online DICOM image stacks are available for this article. ^©RSNA, 2020.

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.

The additional value of the arterial phase in the CT assessment of liver vascular injuries after high-energy blunt trauma

PURPOSE

In the literature, no consensus exists about which CT protocol is to be adopted in patients who underwent high-energy blunt trauma. The aim of the study is to evaluate the additional value of the arterial phase in the CT assessment of vascular injuries of the liver.

METHODS

Admission CT examinations for patients with traumatic injury of the liver due to high-energy blunt trauma, performed between 2011 and 2017 in two major trauma centres, were retrospectively reviewed. Images were analysed for presence or absence of liver parenchymal injury, intrahepatic contained vascular injuries and active bleeding in the arterial and portal venous phase of the CT study.

RESULTS

Two hundred twelve patients have been identified. Parenchymal injuries were detected as isolated in 90.6% of cases, whereas they were associated with vascular injuries in 9.4% of cases: contained vascular injuries in 3.3% and active bleeding in 6.1%. Out of all parenchymal injuries detected on the CT portal venous phase, 90.5% were also detectable in the arterial phases (p < 0.0001). All of the contained vascular injuries were visible in the CT arterial phase, whereas they were detectable in 28.5% of cases also during the venous phase (p = 0.02). All 13 cases of active bleeding were detected on the CT venous phase, and 76.9% of these cases were also revealed in the arterial phase, thus confirming their arterial origin (p = 0.22).

CONCLUSION

The addiction of the arterial phase to the venous phase in the CT assessment of patients who underwent high-energy blunt trauma allows an accurate identification and characterization of traumatic vascular injuries, so distinguishing between patients suitable for conservative management and those requiring interventional or surgical treatment.

Optimal CT protocol for the diagnosis of active bleeding in abdominal trauma patients

OBJECTIVES

The aim of this study is to compare the radiologic diagnostic performance of arterial phase, portal phase and combined phase computed tomography (CT) for traumatic abdominal injury. In addition, this study is attempted to decrease lifetime attributable risks (LARs) of cancer due to radiation exposure by using optimal CT protocol.

MATERIALS AND METHODS

A total of 114 consecutive patients with a traumatic abdominal injury and an abdominal hematoma on CT were enrolled at a single tertiary regional trauma center between January 2016 and March 2017. Each CT protocol set was independently reviewed by three radiologists, and the diagnostic performance of all three CT phases were compared with regard to the capability to detect active bleeding, contained vascular injuries, and organ injuries. Additionally, LARs for cancer incidence and mortality were calculated using dose-length product values, for each phase of CT.

RESULTS

The pooled area under the receiver operating characteristic curves for the diagnosis of active bleeding, contained vascular injuries, and organ injuries ranged from 0.910 to 0.922, 0.643 to 0.723, and 0.948 to 0.915 for arterial, portal, and combined phase CT, respectively. There was no statistically significant difference in the diagnosis of active bleeding and organ injuries for any combination of two phase sets. The mean LARs for cancer incidence was 0.059%, 0.062% and 0.121% during arterial, portal and combined phase CT, respectively.

CONCLUSION

Single phase CT could be a potential protocol for abdominal trauma patients. Use of single phase CT could significantly decrease the incidence of radiation-associated cancer in the future.

Triple-split-bolus versus single-bolus CT in abdominal trauma patients: a comparative study

Background Split-bolus computed tomography (CT) is a recent development in trauma imaging. Instead of multiple scans in different contrast phases after a single contrast bolus, split-bolus protocols consist of one single scan of the thorax and abdomen after two or three contrast injections at different points of time. Purpose To evaluate and compare image quality and injury findings of a new triple-split-bolus CT (TS-CT) protocol of thorax and abdomen with those of a portal venous phase CT (PV-CT) in the same patient group. Material and Methods Trauma patients in 2009-2012 who underwent both the TS-CT initially and a PV-CT during the next six weeks were included. The TS-CT examination was performed as one CT run after application of three contrast boluses (total 175 mL) to enhance renal pelvis and urinary tract, the abdominal organs, and the large arterial vessels. The PV-CT had a fixed delay of 85 s. We measured attenuation in Hounsfield units (HU), evaluated possible organ injury and assessed image quality on a 5-point scale. Results Thirty-five patients were included. Attenuation measurements of major abdominal vessels, organs, and renal pelvis were significantly higher with the TS-CT protocol. Performance in organ injury diagnosis and image quality was equal in both protocols. Conclusion The overall performance of the TS-CT protocol is similar to the standard PV-CT. Excellent visualization of the arterial tree and the collecting system may eliminate the need for separate scans.

Evaluation of a single-pass with biphasic intravenous contrast medium injection CT protocol for the assessment of complications post-simultaneous pancreas-kidney transplant

AIM

To evaluate the use of a single-pass with biphasic intravenous contrast medium injection computed tomography (CT) protocol to provide diagnostic quality CT studies for the assessment of complications post-simultaneous pancreas-kidney transplant (SPK).

MATERIALS AND METHODS

This was an audit of practice and the need for informed consent was waived. The protocol was used in consecutive patients undergoing CT to exclude intra-abdominal sepsis post-SPK between June and December 2015. Single CT acquisition of the abdomen and pelvis was initiated 70 seconds after the start of biphasic contrast medium injection (66 ml at 1.2 ml/s, followed by 34 ml at 2.4 ml/s, 370 mg iodine/ml). The named transplant pancreas vessels were identified and the attenuation values of the blood within were measured. Diagnostic quality was confirmed if values were >211 HU and >80 HU in the arteries and veins, respectively.

RESULTS

Thirteen CT studies were performed in 10 patients. CT studies were excluded due to complete pancreatic necrosis, and transplant superior mesenteric artery (SMA) thrombus with pancreatic head ischaemia causing effacement of the transplant superior mesenteric vein (SMV). Diagnostic quality of the analysed CT studies were confirmed with mean attenuation value of blood >211 HU in the transplant pancreatic arteries (SMA=259.0±51.4 HU, splenic artery=245.3±37.5 HU), and >80 HU in the pancreatic veins (SMV=195.4±36.2 HU, splenic vein=185.1±54.2 HU).

CONCLUSION

Diagnostic quality CT studies were obtained using the single-pass CT protocol. Radiation exposure to patients may be reduced with this protocol, while permitting simultaneous assessment of parenchymal and vascular complications post-SPK.

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.

[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%.

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.

Traumatic injuries of the thoracic aorta: The role of imaging in diagnosis and treatment

Traumatic injury of the thoracic aorta remains the leading cause of death in multiple trauma patients and it requires urgent management. Computed tomography has a key diagnostic role and allows the clinician to choose an appropriate treatment strategy. The development of new classifications, based on a better understanding of the mechanisms of these injuries, has clarified the indications for treatment. Advances in techniques, especially in endovascular management, have contributed to improving prognosis for patients. Interventional radiology, which usually consists of endovascular placement of a covered stent, now constitutes the gold standard treatment in these injuries. Due to the potentially grave prognosis of these patients, it is crucial to know how to detect these injuries and to describe the imaging signs of serious damage.

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.