Penetrating aerodigestive injuries in the neck: a proposed CT-aided modified selective management algorithm.

OBJECTIVES: To determine the specific CT findings of penetrating neck wound profile predicting aerodigestive injuries, diagnostic performance of CTA and to propose a modified selective management algorithm to reduce nontherapeutic invasive procedures. METHODS: We retrospectively evaluated CTAs of 102 patients to determine the presence of various CT signs. "Trajectory"-based signs included trajectory of the wound extending into the aerodigestive tract and trajectory violating the deep neck spaces. "Conventional" signs included transcervical injury; wall defect; air or blood in the deep neck spaces; irregular or thickened aerodigestive tract; and active mucosal bleeding. RESULTS: Trajectory of the wound extending into the aerodigestive tract (sensitivity 76 %, specificity 97 %) and trajectory of the wound violating the suprahyoid deep neck spaces or the infrahyoid visceral space (sensitivity 97 %, specificity 55 %) were the best predictors of injury on regression analysis. The most specific "conventional" CT signs were "wall defect" and "active mucosal bleed", but had very low sensitivity. The sensitivity of CTA for detecting an injury ranged from 89.5 % to 92 %, specificity ranged from 62.5 % to 89 %. CONCLUSION: CTA can be a useful technique in detecting aerodigestive injury. Our proposed management algorithm can exclude an injury with high degree of confidence (sensitivity 97 %). KEY POINTS: • Trajectory-based CT signs predict aerodigestive injury after penetrating neck trauma. • Surgery should be considered when trajectory extends into the infra-arytenoid aerodigestive tract. • Endoscopy or exploration should be considered when trajectory violates deep neck spaces. • This modified approach can decrease negative explorations and invasive diagnostic procedures.

Diagnostic accuracy of triple-contrast multi-detector computed tomography for detection of penetrating gastrointestinal injury: a prospective study.

PURPOSE: Neither the performance of CT in diagnosing penetrating gastrointestinal injury nor its ability to discriminate patients requiring either observation or surgery has been determined. MATERIALS AND METHODS: This was a prospective, single-institutional observational study of patients with penetrating injury to the torso who underwent CT. Based on CT signs, reviewers determined the presence of a gastrointestinal injury and the need for surgery or observation. The primary outcome measures were operative findings and clinical follow-up. CT results were compared with the primary outcome measures. RESULTS: Of one hundred and seventy-one patients (72 gunshot wounds, 99 stab wounds; age range, 18-57 years; median age, 28 years) with penetrating torso trauma who underwent CT, 45 % were followed by an operation and 55 % by clinical follow up. Thirty-five patients had a gastrointestinal injury at surgery. The sensitivity, specificity, and accuracy of CT for diagnosing a gastrointestinal injury for all patients were each 91 %, and for predicting the need for surgery, they were 94 %, 93 %, 93 %, respectively. Among the 3 % of patients who failed observation, 1 % had a gastrointestinal injury. CONCLUSION: CT is a useful technique to diagnose gastrointestinal injury following penetrating torso injury. CT can help discriminate patients requiring observation or surgery. KEY POINTS: • The most sensitive sign is wound tract extending up to gastrointestinal wall. • The most accurate sign is gastrointestinal wall thickening. • Triple-contrast CT is a useful technique to diagnose gastrointestinal injury. • Triple-contrast CT helps to discriminate patients requiring observation and surgery.

Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist.

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.

Blunt splenic injury: use of a multidetector CT-based splenic injury grading system and clinical parameters for triage of patients at admission.

PURPOSE: To assess the use of a dual-phase multidetector computed tomography (CT)-based grading system alone and in combination with assessment of clinical parameters at triage of patients with blunt splenic injury for determination of appropriate treatment (observation, splenic artery embolization [SAE], or splenic surgery). MATERIALS AND METHODS: This HIPAA-compliant retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between January 2009 and July 2011, 171 hemodynamically stable patients with blunt splenic injury underwent multidetector CT at admission to the hospital. Images were reviewed by applying a multidetector CT-based grading system, and the amount of hemoperitoneum was quantified. Demographic data, vital signs, laboratory values, injury severity score, abbreviated injury severity, final treatment decision, and success of nonsurgical treatment were reviewed. Receiver operating characteristic curves and stepwise logistic regression analyses were performed to determine the optimal parameters for effective triage of patients. RESULTS: One hundred seventy one patients with splenic injury underwent multidetector CT. At triage, clinical treatment decisions were made, and patients received either observation (85 of 171 [50%]) or splenic intervention (surgery, 19 of 171 [11%] or splenic angiography, 67 of 171 [39%]). Four patients underwent SAE after unsuccessful observation. Six of 171 (3.5%) other patients received unsuccessful nonsurgical treatment with SAE. No patients who received observation required splenectomy. Areas under the receiver operating characteristic curve (AUCs) showed that the CT grading system was the best individual predictor of successful observation (AUC, 0.95), and stepwise logistic regression analysis results showed that multidetector CT grade and the abbreviated injury scale score (AUC, 0.97; P = .02) were the best combination of variables for selection of patients for observation versus splenic intervention. The combination of abbreviated injury scale score, systolic blood pressure reading, and serum glucose level was the best triage model for decision making between splenectomy and SAE (AUC, 0.84). CONCLUSION: The best individual predictor of successful observation in patients with blunt splenic injury was the CT-based grading system. Multidetector CT grade and abbreviated injury scale score were the best combination of variables for selection of patients for observation versus splenic intervention.

Traumatic optic neuropathy prediction after blunt facial trauma: derivation of a risk score based on facial CT findings at admission.

PURPOSE: To determine the specific facial computed tomographic (CT) findings that can be used to predict traumatic optic neuropathy (TON) in patients with blunt craniofacial trauma and propose a scoring system to identify patients at highest risk of TON. MATERIALS AND METHODS: This study was compliant with HIPAA, and permission was obtained from the institutional review board. Facial CT examination findings in 637 consecutive patients with a history of blunt facial trauma were evaluated retrospectively. The following CT variables were evaluated: midfacial fractures, extraconal hematoma, intraconal hematoma, hematoma along the optic nerve, hematoma along the posterior globe, optic canal fracture, nerve impingement by optic canal fracture fragment, extraconal emphysema, and intraconal emphysema. A prediction model was derived by using regression analysis, followed by receiver operating characteristic analysis to assess the diagnostic performance. To examine the degree of overfitting of the prediction model, a k-fold cross-validation procedure (k = 5) was performed. The ability of the cross-validated model to allow prediction of TON was examined by comparing the mean area under the receiver operating characteristic curve (AUC) from cross-validations with that obtained from the observations used to create the model. RESULTS: The five CT variables with significance as predictors were intraconal hematoma (odds ratio, 12.73; 95% confidence interval [CI]: 5.16, 31.42; P < .001), intraconal emphysema (odds ratio, 5.21; 95% CI: 2.03, 13.36; P = .001), optic canal fracture (odds ratio, 4.45; 95% CI: 1.91, 10.35; P = .001), hematoma along the posterior globe (odds ratio, 0.326; 95% CI: 0.111, 0.958; P = .041), and extraconal hematoma (odds ratio, 2.36; 95% CI: 1.03, 5.41; P = .042). The AUC was 0.818 (95% CI: 0.734, 0.902) for the proposed model based on the observations used to create the model and 0.812 (95% CI: 0.723, 0.9) after cross-validation, excluding substantial overfitting of the model. CONCLUSION: The risk model developed may help radiologists suggest the possibility of TON and prioritize ophthalmology consults. However, future external validation of this prediction model is necessary.

Multidetector CT of blunt cervical spine trauma in adults.

A number of new developments in cervical spine imaging have transpired since the introduction of 64-section computed tomographic (CT) scanners in 2004. An increasing body of evidence favors the use of multidetector CT as a stand-alone screening test for excluding cervical injuries in polytrauma patients with obtundation. A new grading scale that is based on CT and magnetic resonance (MR) imaging findings, the cervical spine Subaxial Injury Classification and Scoring (SLIC) system, is gaining acceptance among spine surgeons. Radiographic measurements described for the evaluation of craniocervical distraction injuries are now being reevaluated with the use of multidetector CT. Although most patients with blunt trauma are now treated nonsurgically, evolution in the understanding of spinal stability, as well as the development of new surgical techniques and hardware, has driven management strategies that are increasingly favorable toward surgical intervention. It is therefore essential that radiologists recognize findings that distinguish injuries with ligamentous instability or a high likelihood of nonfusion that require surgical stabilization from those that are classically stable and can be treated with a collar or halo vest alone. The purpose of this article is to review the spectrum of cervical spine injuries, from the craniocervical junction through the subaxial spine, and present the most widely used grading systems for each injury type.

Optimizing trauma multidetector CT protocol for blunt splenic injury: need for arterial and portal venous phase scans.

PURPOSE: To retrospectively compare the diagnostic performance of arterial, portal venous, and dual-phase computed tomography (CT) for blunt traumatic splenic injury. MATERIALS AND METHODS: Informed consent was waived for this institutional review board-approved, HIPAA-compliant study. Retrospective record review identified 120 blunt trauma patients (87 male [72.5%] 33 female [27.5%]; age range, 18-94 years) who had undergone dual-phase abdominal CT within 5 years, including 30 without splenic injury, 30 with parenchymal injury only, 30 with splenic active bleeding, and 30 with intrasplenic pseudoaneurysm. Six radiologists each performed blinded review of 20 different cases, and scored the presence of pseudoaneurysm, active bleeding, parenchymal injury, and hematoma; 20 cases were interpreted by all radiologists. Data analysis included calculation of diagnostic performance measures with confidence intervals, areas under receiver operating characteristic curves, and interobserver agreement/variability. RESULTS: For intrasplenic pseudoaneurysm, arterial phase imaging was more sensitive (70% [21 of 30] vs 17% [five of 30]; P < .0002) and more accurate (87% [78 of 90] vs 72% [65 of 90]; P = .0165) than portal venous phase imaging. For active bleeding, arterial phase imaging was less sensitive (70% [21 of 30] vs 93% [28 of 30]; P = .0195) and less accurate (89% [80 of 90] vs 98% [88 of 90]; P = .0168) than portal venous phase imaging. For parenchymal injury, arterial phase CT was less sensitive (76% [68 of 90] vs 93% [84 of 90]; P = .001) and less accurate (81% [nine of 120] vs 95% [114 of 120]; P = .0008) than portal venous phase CT. For all injuries, dual-phase review was equivalent to or better than single-phase review. CONCLUSION: For CT evaluation of blunt splenic injury, arterial phase is superior to portal venous phase imaging for pseudoaneurysm but inferior for active bleeding and parenchymal disruption; dual-phase CT provides optimal overall performance.

Blunt thoracic aortic injuries: CT characterisation and treatment outcomes of minor injury.

OBJECTIVES: Computed tomography (CT)-defined anatomical differentiation of minor and major blunt traumatic aortic injuries (TAIs) was applied to determine injury grade and management/outcomes in minor TAIs, and if the presence of peri-aortic mediastinal haematoma (MH) correlated with TAI grade. METHODS: Admission chest CT of blunt TAI cases during 2005-2011 were reviewed by consensus and categorised as major or minor. Minor was defined as pseudoaneurysm <10 % normal aortic lumen, intimal flap or contour abnormality. Presence/absence of MH was determined. Clinical management/outcome was ascertained from medical records. RESULTS: Of 115 TAIs, 42 were minor (33 with MH, 9 without). Among the 73 with major TAI, 3 had no MH. Twenty-six (62 %) minor TAI patients were managed medically, 12 (29 %) percutaneous stent-grafts, 2 (5 %) died of non-aortic causes and 2 (5 %) underwent surgery. Of 26 managed without intervention, none developed complications from TAI at last clinical or CT follow-up. The relationship between presence/absence of peri-aortic MH and grade of TAI was statistically significant. CONCLUSIONS: More than a third of multi-detector (MD) CT-diagnosed TAIs were minor. Minor TAIs treated medically were stable at last follow-up, suggesting this is a reasonable initial management approach. Absence of MH cannot be relied upon to exclude minor TAI, indicating the need for careful direct aortic inspection. KEY POINTS: • MDCT can differentiate minor from major blunt traumatic aortic injuries. • About one-third of MDCT-diagnosed blunt traumatic aortic injuries are minor. • Minor aortic injuries are not necessarily accompanied by mediastinal haemorrhage. • MDCT diagnosis of minor aortic injury supports application of medical management.

MR imaging and differentiation of cerebral fat embolism syndrome from diffuse axonal injury: application of diffusion tensor imaging.

INTRODUCTION: Cerebral fat embolism syndrome (CFES) mimics diffuse axonal injury (DAI) on MRI with vasogenic edema, cytotoxic edema, and micro-hemorrhages, making specific diagnosis a challenge. The objective of our study is to determine and compare the diagnostic utility of the conventional MRI and DTI in differentiating cerebral fat embolism syndrome from diffuse axonal injury. METHODS: This retrospective study was performed after recruiting 11 patients with severe CFES and ten patients with severe DAI. Three trauma radiologists analyzed conventional MR images to determine the presence or absence of CFES and DAI. DTI analysis of the whole-brain white matter was performed to obtain the directional diffusivities. The results were correlated with clinical diagnosis to determine the diagnostic utility of conventional MRI and DTI. RESULTS: The sensitivity, specificity, and accuracy of conventional MRI in diagnosing CFES, obtained from the pooled data were 76, 85, and 80 %, respectively. Mean radial diffusivity (RD) was significantly higher and the mean fractional anisotropy (FA) was lower in CFES and differentiated subjects with CFES from the DAI group. Area under the receiver operating characteristic (ROC) curve for conventional MRI was 0.82, and for the differentiating DTI parameters the values were 0.75 (RD) and 0.86 (FA), respectively. CONCLUSIONS: There is no significant difference between diagnostic performance of DTI and conventional MRI in CFES, but a difference in directional diffusivities was clearly identified between CFES and DAI.

Diagnosis of traumatic optic neuropathy: application of diffusion tensor magnetic resonance imaging.

BACKGROUND: Using diffusion tensor imaging, we evaluated the directional diffusivities of the optic nerve in patients with traumatic optic neuropathy (TON). METHODS: Our study consisted of 12 patients with unilateral TON, 6 patients with severe traumatic brain injury (comparison group A), and 6 patients with normal conventional brain magnetic resonance imaging (comparison group B). The contralateral optic nerve in patients with TON also was evaluated (comparison group C). Two trauma radiologists, blinded to the clinical diagnosis, independently obtained the directional diffusivities. The intraorbital optic nerve was divided into anterior and posterior segments to evaluate intersegmental differences in directional diffusivities. RESULTS: The mean axial diffusivity (AD) in both optic nerve segments and the mean diffusivity (ADC) in the posterior segment on the affected side were significantly lower and differentiated subjects with TON from those in comparison groups A and B. Area under the receiver operating characteristic curve was 0.762, 0.746, and 0.737 for posterior AD, anterior AD, and posterior ADC, respectively. The mean AD, mean diffusivity, and radial diffusivity were lower in the affected nerves in comparison to the contralateral nerve (comparison group C), but the values did not reach statistical significance. CONCLUSION: Decreased AD and mean diffusivity in the posterior segment of the optic nerve may serve as a biomarker of axonal damage in patients with TON and merits further investigation as a predictor of initial visual acuity and potential visual recovery.

MDCT diagnosis of post-traumatic hepatic arterio-portal fistulas.

The purpose of this study is to evaluate the performance of multidetector computed tomography (MDCT) in diagnosing arterioportal fistulas (APF) in high-grade liver injury. A retrospective analysis of catheter-based hepatic angiograms performed for major penetrating and blunt liver injuries identified 11 patients with APFs. Using the trauma registry, two additional demographically matched groups with and without liver injury were formed. A randomized qualitative consensus review of 33 MDCTs was performed by three trauma radiologists for the following MDCT findings of APF: transient hepatic parenchymal attenuation differences (THPAD), early increased attenuation of a peripheral or central portal vein compared with the main portal vein, and the "double-barrel" or "rail tract" signs. THPAD was the most sensitive finding and also had a high specificity for diagnosing APF. Both the early increased attenuation of a peripheral or central portal vein compared with the main portal vein and the double-barrel or rail tract signs had a100% specificity and a sensitivity of 64% and 36%, respectively. Measurement of differences in attenuation values between the APF and the contralateral central portal vein was most sensitive and specific in diagnosing APF. Traumatic APF of the liver can be optimally diagnosed with arterial phase imaging of solid organ using MDCT.

Acute traumatic aortic injuries: posttherapy multidetector CT findings.

Acute traumatic aortic injury is a life-threatening entity that requires emergent treatment. Treatment was once performed with left thoracotomy, resection of the damaged aortic segment, and placement of an interposition graft. Within the past decade, endovascular therapy has gained increased acceptance, primarily because of a significant decrease in mortality and morbidity compared with those of surgery. The authors reviewed the experience with management of acute traumatic aortic injuries at their institution, as well as that reported in the literature. Complications after endovascular repair include endoleak, endograft collapse, stroke, upper extremity ischemia, paraplegia, graft infection, endograft structural failure, missed injury or stent migration, and access site complications. After surgical repair, paraplegia and ischemia to other organs, graft dehiscence, graft infection, and graft stenosis may occur. With the growing use of endovascular management of acute traumatic aortic injuries and the increased likelihood of patient survival, the radiologist will be expected to be familiar with the findings in these patients and is positioned to play a critical role in early recognition of potential complications. Early diagnosis of the complications of therapy for aortic injury is imperative for reduction of mortality and morbidity.

MDCT diagnosis of penetrating diaphragm injury.

The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries.

Diagnostic determinants of craniocervical distraction injury in adults.

OBJECTIVE: Craniocervical distraction injury is a class of injuries that involve the skull base, the atlas, and the axis. Although these injuries often are overt imaging and clinical findings, the injury can be masked during unreliable physical examinations and difficult to identify during diagnostic imaging. The goal of this study was to identify on coronal and sagittal CT multiplanar reformations precise measurements and qualitative relations between anatomic landmarks that can help in establishing the diagnosis of craniocervical distraction injury. MATERIALS AND METHODS: We performed a retrospective review of the cases of 35 patients with craniocervical distraction injury admitted to our trauma center from 2000 to 2006. Two independent radiologists made several qualitative and quantitative anatomic assessments on reformatted CT images through the craniocervical junctions (skull base through C2) of the 35 patients and of 50 other patients sustaining blunt trauma who were discharged without findings of cervical spinal injury. Logistic regression, recursive partitioning, and multivariate analysis were performed in an attempt to find measurements that differentiated the groups. RESULTS: Among the patients with craniocervical distraction injury, statistically significant positive correlations were found in several measurements, including midline occiput-C1 spinolaminar distance (p=0.0016), midline C1-C2 spinolaminar distance (p<0.0001), basion-dens distance (p<0.0001), sum of condylar displacement (p=0.0002), and basion-posterior axial line distance (p<0.0001). CONCLUSION: Several quantitative parameters on sagittal and coronal multiplanar CT reformations can be used to differentiate patients with craniocervical distraction injury from patients without this injury.

Evaluation of a single-pass continuous whole-body 16-MDCT protocol for patients with polytrauma.

OBJECTIVE: The purpose of this study was to compare a conventional multiregional MDCT protocol with two continuous single-pass whole-body MDCT protocols in imaging of patients with polytrauma. SUBJECTS AND METHODS: Ninety patients with polytrauma underwent whole-body 16-MDCT with a conventional (n=30) or one of two single-pass (n=60) protocols. The conventional protocol included unenhanced scans of the head and cervical spine and contrast-enhanced helical scans (140 mL, 4 mL/s, 300 mg I/mL) of the thorax and abdomen. The single-pass protocols consisted of unenhanced scans of the head followed by one-sweep acquisition from the circle of Willis through the pubic symphysis with a biphasic (150 mL, 6 and 4 mL/s, 300 mg I/mL) or monophasic (110 mL, 4 mL/s, 400 mg I/mL) injection. Acquisition times and interval delays between head, chest, and abdominal scans were recorded. Contrast enhancement was measured in the aortic arch, liver, spleen, and kidney. Diagnostic image quality in the same areas was assessed on a 4-point scale. RESULTS: Median acquisition times for the single-pass protocols were significantly shorter (-42.5%) than the acquisition time for the conventional protocol. No significant differences were found in mean enhancement values in the aorta, liver, spleen, and kidney for the three protocols. The image quality with both single-pass protocols was better than that with the conventional protocol in assessment of the mediastinum and cervical spine (p<0.05). There was no significant difference between the single-pass protocols. CONCLUSION: Use of single-pass continuous whole-body MDCT protocols can significantly decrease examination time for patients with polytrauma and improve image quality compared with a conventional serial scan protocol. Monophasic injection with highly concentrated contrast medium can reduce injection flow rate and should therefore be preferred to a biphasic injection technique.

Diagnosis of blunt cerebrovascular injuries with 16-MDCT: accuracy of whole-body MDCT compared with neck MDCT angiography.

OBJECTIVE: The objective of our study was to determine whether whole-body 16-MDCT and neck MDCT angiography (MDCTA) can be used to diagnose blunt cerebrovascular injuries with comparable accuracy using angiography as the reference standard. MATERIALS AND METHODS: Retrospective review of radiology reports and prospective clinical observation identified 108 blunt trauma patients examined with either whole-body MDCT or neck MDCTA followed by angiography over a 23-month period. From this group, results from the retrospective interpretations of 77 whole-body MDCT and 48 neck MDCTA examinations were compared with the results extracted from angiography reports to estimate the accuracy of each protocol for detecting blunt cerebrovascular injuries. Fisher's exact test was used to determine any significant difference in the results of those patients scanned with both protocols. RESULTS: Angiography confirmed blunt cerebrovascular injury in 83 patients, with 25 (30%) showing multiple sites of injury. Most injuries were detected in cervical arterial segments. The respective sensitivities of whole-body MDCT and neck MDCTA were 69% (36/52) and 64% (16/25) for cervical internal carotid artery injuries, and specificities were 82% (58/71) and 94% (49/52). Respective sensitivities for cervical vertebral artery injuries were 74% (17/23) and 68% (13/19), and specificities were 91% (60/66) and 100% (40/40). In 17 patients scanned with both protocols, the results were not significantly different (carotid arteries, p = 1.00; vertebral arteries, p = 0.68). CONCLUSION: Whole-body 16-MDCT and neck MDCTA can be used to diagnose blunt cerebrovascular injuries with comparable accuracy. Both show high specificities for cervical arterial injury. The sensitivity of whole-body 16-MDCT is sufficiently high to serve as an initial screening examination for blunt cerebrovascular injuries.

Posttraumatic cerebral infarction: incidence, outcome, and risk factors.

BACKGROUND: Outcome in patients with traumatic brain injury (TBI) is often affected by secondary insults including posttraumatic cerebral infarction (PTCI). The incidence of PTCI after TBI was previously reported to be 2% with no mortality impact. We suspected that recent advances in imaging modalities and treatment might affect incidence and outcome. We sought to define the incidence and mortality impact of PTCI. We also identified risk factors associated with PTCI. METHODS: We retrospectively reviewed all patients admitted between 2004 and 2006 with severe TBI (brain Abbreviated Injury Scale [AIS] score >2, Glasgow Coma Scale score [GCS] <9). Demographics, injury specifics, and clinical data were abstracted. All brain imaging studies were reviewed with an attending trauma radiologist. Statistical analysis of outcome data were performed using chi and Student's t test and multivariate analysis was performed using logistic regression to identify independent risk factors. RESULTS: Of the 384 patients identified with severe TBI; 93% sustained a blunt injury, 75% were men. Mortality was 21%, and 48% had a brain AIS score of 5. Mean age was 36 years (11-90 years), admission GCS score was 5 (3-8), and Injury Severity Score was 32 (9-75). Thirty-one (8%) had a confirmed PTCI. The PTCI group had a significantly increased mortality (45% vs. 19%, p < 0.002), hospital length of stay (LOS) (25 days vs. 18 days, p < 0.02), and intensive care unit LOS (21 days vs. 15 days, p < 0.03). In multivariate analysis, sex, age, Injury Severity Score, Revised Trauma Score, admission GCS, and brain AIS were not associated with PTCI; whereas the presence of blunt cerebral vascular injury [odds ratio (OR) 4.0, 95% confidence interval (CI) 1.9-8.7], the need for craniotomy (OR 3.0, 95% CI 1.2-6.9), or treatment with recombinant factor VIIa (OR 3.1, 95% CI 1.1-8.0) were each independently associated with an increased risk of PTCI. CONCLUSIONS: The incidence of PTCI in patients with severe TBI is higher after severe brain injury than previously thought. PTCI has a significant impact on mortality and LOS. The presence of a blunt cerebral vascular injury, the need for craniotomy, or treatment with factor VIIa are risk factors for PTCI. Recognition of this secondary brain insult and the associated risk factors may help identify the group at risk and tailor management of patients with severe TBI.

Optimization of selection for nonoperative management of blunt splenic injury: comparison of MDCT grading systems.

OBJECTIVE: The purpose of this study was to compare the usefulness of two CT grading systems of blunt splenic trauma in predicting which patients need surgery or angioembolization. MATERIALS AND METHODS: Four hundred patients in hemodynamically stable condition admitted with blunt splenic injury were included in the study. All patients underwent contrast-enhanced MDCT. Grade of splenic injury was prospectively assigned according to the American Association for the Surgery of Trauma (AAST) splenic injury scale. Patients were treated with surgical intervention, splenic arteriography with or without embolization, or observation alone. All MDCT images were retrospectively reviewed and regraded according to a novel grading system that specifically incorporates the findings of active bleeding or splenic vascular injury, including pseudoaneurysm and arteriovenous fistula. Receiver operating characteristics curves were generated with both grading systems for all splenic interventions, and statistical analyses were performed. RESULTS: The area under the ROC curves for the new splenic grading system for splenic arteriography, surgery, and both interventions exceeded 80%. The area under the curve for the new splenic grading system was greater than that for the AAST injury scale for all interventions. Differences were found to be statistically significant for splenic arteriography (p = 0.0036) and the combination of arteriography and surgery (p = 0.0006). CONCLUSION: The proposed CT grading system is better than the AAST system for predicting which patients with blunt splenic trauma need arteriography or splenic intervention.

Imaging of blunt cerebrovascular injuries.

Blunt cerebrovascular injuries are uncommon but potentially devastating injuries that can lead to stroke and death. While uncommon, appreciation of the seriousness of these injuries, a high index of suspicion in high risk patients, and aggressive screening of multitrauma patients leads to early diagnosis of asymptomatic lesions that may be amenable to treatment prior to the onset of ischemia. The radiologist can play a vital role in the early diagnosis, follow-up, and, in some cases, treatment of these challenging injuries.

Diagnosis of blunt traumatic aortic injury 2007: still a nemesis.

In recent years, the use of multidetector computed tomography (MDCT) for the diagnosis of acute thoracic injury in blunt trauma has expanded. MDCT has shown high accuracy for the diagnosis or exclusion of injury to the aorta and its primary branches, decreasing the need for thoracic angiography and allowing earlier treatment of this often rapidly fatal lesion. With increasing use of MDCT, more subtle injuries and variants of vascular anatomy are being recognized that create pitfalls in the diagnosis. Of perhaps more concern is the recognition that aortic injury can occur with little or no associated mediastinal hematoma, the principle chest radiographic finding indicating a need for further imaging. The importance of recognizing unusual sites of aortic injury, congenital variants of mediastinal anatomy, the precise extent of injury, and the anatomic pathology present as key factors in deciding among treatment options is emphasized.