Diffusion Tensor Imaging Parameter Obtained during Acute Blunt Cervical Spinal Cord Injury in Predicting Long-Term Outcome.

There are no reliable neuroimaging biomarkers to predict long-term outcome after spinal cord injury. This prospective longitudinal study evaluates diffusion tensor imaging (DTI) in predicting long-term outcome after cervical spinal cord injury (CSCI). We investigate the admission DTI parameters measured in 30 patients with CSCI, with 16 of them followed up to one year, and 15 volunteers serving as controls. All magnetic resonance imaging examinations were performed within 24 h of injury. The DTI parameters were measured in patients and controls, avoiding areas of hemorrhage in patients and at corresponding upper/middle/lower regions of the spinal cord in controls. Stepwise regression analysis was performed to find relevant parameters (normalized DTI values, age, sex, hemorrhagic contusion [HC or non-HC]) that correlated with two primary outcome measures: patient International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) motor and Spinal Cord Independence Measure (SCIM III) scores at one year. Among all DTI measures, axial diffusivity (AD) most strongly correlated with both motor (r2 = 0.76, p < 0.01) and SCIM III scores (r2 = 0.77, p < 0.01) at one year. Further stepwise regression indicated that including AD (p = 0.0001) and presence of HC (p < 0.0001) in the regression model provided the best model fit for one year ISNCSCI (r2 = 0.93). The AD is a more specific parameter for axonal injury than radial diffusivity; this may indicate that axonal injury in the cord is the main factor affecting patient recovery. Our study demonstrates DTI measurement at the CSCI is a potential neuroimaging biomarker in predicting long-term neurological and functional outcome in blunt CSCI.

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.

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.

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.

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.

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.

Vascular complications of penetrating brain injury: comparison of helical CT angiography and conventional angiography.

OBJECT: The authors conducted a study to compare the sensitivity and specificity of helical CT angiography (CTA) and digital subtraction angiography (DSA) in detecting intracranial arterial injuries after penetrating traumatic brain injury (PTBI). METHODS: In a retrospective evaluation of 48 sets of angiograms from 45 consecutive patients with PTBI, 3 readers unaware of the DSA findings reviewed the CTA images to determine the presence or absence of arterial injuries. A fourth reader reviewed all the disagreements and decided among the 3 interpretations. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTA were calculated on a per-injury basis and in a subpopulation of patients with traumatic intracranial aneurysms (TICAs). RESULTS: Sensitivity of CTA for detecting arterial injuries was 72.7% (95% CI 49.8%-89.3%); specificity, 93.5% (95% CI 78.6%-99.2%); PPV, 88.9% (95% CI 65.3%-98.6%); and NPV, 82.9% (95% CI 66.4%-93.4%). All 7 TICAs were correctly identified by CTA. Sensitivity, specificity, PPV, and NPV of CTA in detecting TICAs were 100%. To compare agreement with DSA, the standard of reference, confidence scores categorized as low, intermediate, and high probability yielded an overall effectiveness of 77.8% (95% CI 71.8%-82.9%). CONCLUSIONS: Computed tomography angiography had limited overall sensitivity in detecting arterial injuries in patients with PTBI. However, it was accurate in identifying TICAs, a subgroup of injuries usually managed by either surgical or endovascular approaches, and non-TICA injuries involving the first-order branches of intracranial arteries.

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.

Comparative effectiveness of surgical versus nonoperative management of unilateral, nondisplaced, subaxial cervical spine facet fractures without evidence of spinal cord injury: clinical article.

OBJECT: Facet joints are major stabilizers of cervical motion allowing for effortless and pain-free multidimensional cervical spine movements without significant linear or rotational translation, thus minimizing any chance for spinal cord or nerve root impingement. Unilateral, nondisplaced subaxial facet fractures do not meet the conventional criteria for spinal instability under physiological loads. Limited evidence indicates that even with no or minimal displacement, 20%-80% of these fractures fail nonoperative management. The risk factors for instability in isolated nondisplaced subaxial facet fractures remain uncertain. In this retrospective study of prospectively collected data, the authors attempted to identify the predictors of failure in the management of isolated, nondisplaced subaxial facet fractures admitted to their Level I trauma center over a 10-year period. METHODS: Demographic, clinical, imaging, and follow-up data for 25 patients with unilateral nondisplaced subaxial facet fractures who were managed surgically (n = 10) or nonoperatively (n = 15) were statistically analyzed. RESULTS: The mean age of the patients was 38 years, 19 were male, and 21 of the fractures were the result of either motor vehicle accidents or falls. The mean motor score on the American Spinal Injury Association scale was 99.2, and the mean Subaxial Injury Classification (SLIC) severity score was 3 (operated 3.5, nonoperated 2.3). Allen mechanistic classification included 22 compressive-extension Stage 1 and 2 distractive-extension Stage 1 fractures. Subaxial facet fractures involved C-7 in 17 patients (68%), C-6 in 7 (28%), and C-3 in 1 (4%). The anatomical plane of fracture through the lateral mass was sagittal in 12 patients, axial in 8, and coronal in 3 patients. Nondisplaced floating lateral mass injuries were noted in 2 patients. The mean instability score, considering 7 components of the discoligamentous complex on MRI, was 3.2 (operated 3.6, nonoperated 3.0). Ten (40%) of 25 patients in this investigation did not have successful management, 9 in the nonoperated and 1 in the operated group (p = 0.018). Unsuccessful management was significantly greater in younger patients (p = 0.0008), possibly indicating selection bias (p = 0.07, Wilcoxon ranksum test). Fracture plane, instability, and SLIC scores did not play a significant role in treatment failure in this study. CONCLUSIONS: In this study, surgery was superior to nonoperative management of isolated, nondisplaced, or minimally displaced subaxial cervical spine facet fractures.

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.

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.

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.

Implementation of 24/7 radiology services in an academic medical centre level 1 trauma centre: impact on trauma resuscitation unit length of stay and economic benefit analysis.

STUDY OBJECTIVE: To evaluate the impact of 24/7 radiology services on trauma resuscitation unit (TRU) length of stay (LOS) for patients with minor trauma and to analyse the economic benefits of such an impact from trauma centre perspective. METHODS: The study was HIPAA compliant and had IRB approval. Data were extracted from hospital and radiology information systems. Inclusion criteria specified patients: (a) with minor trauma (i.e., Injury Severity Score<16 and Maximum Abbreviated Injury Scale<4); (b) cross-sectional imaging performed between 12 and 7AM; and (c) admission during 2006 (before 24/7 coverage; comparison group 1) or 2007 (24/7 coverage). Mean, median, standard deviation, and variance for the groups were determined. The theoretical economic benefit achieved with 24/7 radiology coverage was estimated from decreases in TRU LOS for each patient. RESULTS: Totals of 1087 and 1323 patients for 2006 and 2007, respectively, met our selection criteria. Mean TRU LOS decreased from 11.19 to 8.25 h (26%; P<0.001). The median decreased from 10.8 to 7.2 h (33%; P<0.001). The (Q3-Q1) indicator, used as a proxy for variance and spread, decreased from 7.36 to 5.76 h. Theoretical economic benefits from 24/7 radiology coverage were achieved by the product of TRU bed fixed costs with mean decrease in TRU LOS for the calendar year 2007, which equaled $340,069. CONCLUSION: The economic benefits of 24/7 radiology services are related to LOS, which can be shortened by limiting patient discharge delays resulting from report unavailability. This can be a cost-saving replacement for conventional radiology practice when the trauma centre makes appropriate use of vacant TRU beds to realise its opportunity cost.

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.

Predictors of pulmonary complications in blunt traumatic spinal cord injury.

OBJECT: Pulmonary complications are the most common acute systemic adverse events following spinal cord injury (SCI), and contribute to morbidity, mortality, and increased length of hospital stay (LOS). Identification of factors associated with pulmonary complications would be of value in prevention and acute care management. Predictors of pulmonary complications after SCI and their effect on neurological recovery were prospectively studied between 2005 and 2009 at the 9 hospitals in the North American Clinical Trials Network (NACTN). METHODS: The authors sought to address 2 specific aims: 1) define and analyze the predictors of moderate and severe pulmonary complications following SCI; and 2) investigate whether pulmonary complications negatively affected the American Spinal Injury Association (ASIA) Impairment Scale conversion rate of patients with SCI. The NACTN registry of the demographic data, neurological findings, imaging studies, and acute hospitalization duration of patients with SCI was used to analyze the incidence and severity of pulmonary complications in 109 patients with early MR imaging and long-term follow-up (mean 9.5 months). Univariate and Bayesian logistic regression analyses were used to analyze the data. RESULTS: In this study, 86 patients were male, and the mean age was 43 years. The causes of injury were motor vehicle accidents and falls in 80 patients. The SCI segmental level was in the cervical, thoracic, and conus medullaris regions in 87, 14, and 8 patients, respectively. Sixty-four patients were neurologically motor complete at the time of admission. The authors encountered 87 complications in 51 patients: ventilator-dependent respiratory failure (26); pneumonia (25); pleural effusion (17); acute lung injury (6); lobar collapse (4); pneumothorax (4); pulmonary embolism (2); hemothorax (2), and mucus plug (1). Univariate analysis indicated associations between pulmonary complications and younger age, sports injuries, ASIA Impairment Scale grade, ascending neurological level, and lesion length on the MRI studies at admission. Bayesian logistic regression indicated a significant relationship between pulmonary complications and ASIA Impairment Scale Grades A (p = 0.0002) and B (p = 0.04) at admission. Pulmonary complications did not affect long-term conversion of ASIA Impairment Scale grades. CONCLUSIONS: The ASIA Impairment Scale grade was the fundamental clinical entity predicting pulmonary complications. Although pulmonary complications significantly increased LOS, they did not increase mortality rates and did not adversely affect the rate of conversion to a better ASIA Impairment Scale grade in patients with SCI. Maximum canal compromise, maximum spinal cord compression, and Acute Physiology and Chronic Health Evaluation-II score had no relationship to pulmonary complications.

Intramedullary lesion expansion on magnetic resonance imaging in patients with motor complete cervical spinal cord injury.

OBJECT: The authors performed a study to determine if lesion expansion occurs in humans during the early hours after spinal cord injury (SCI), as has been established in rodent models of SCI, and to identify factors that might predict lesion expansion. METHODS: The authors studied 42 patients with acute cervical SCI and admission American Spinal Injury Association Impairment Scale Grades A (35 patients) and B (7 patients) in whom 2 consecutive MRI scans were obtained 3-134 hours after trauma. They recorded demographic data, clinical information, Injury Severity Score (ISS), admission MRI-documented spinal canal and cord characteristics, and management strategies. RESULTS: The characteristics of the cohort were as follows: male/female ratio 37:5; mean age, 34.6 years; and cause of injury, motor vehicle collision, falls, and sport injuries in 40 of 42 cases. The first MRI study was performed 6.8 ±2.7 hours (mean ± SD) after injury, and the second was performed 54.5 ± 32.3 hours after injury. The rostrocaudal intramedullary length of the lesion on the first MRI scan was 59.2 ± 16.1 mm, whereas its length on the second was 88.5 ± 31.9 mm. The principal factors associated with lesion length on the first MRI study were the time between injury and imaging (p = 0.05) and the time to decompression (p = 0.03). The lesion's rate of rostrocaudal intramedullary expansion in the interval between the first and second MRI was 0.9 ± 0.8 mm/hour. The principal factors associated with the rate of expansion were the maximum spinal cord compression (p = 0.03) and the mechanism of injury (p = 0.05). CONCLUSIONS: Spinal cord injury in humans is characterized by lesion expansion during the hours following trauma. Lesion expansion has a positive relationship with spinal cord compression and may be mitigated by early surgical decompression. Lesion expansion may be a novel surrogate measure by which to assess therapeutic effects in surgical or drug trials.

Correlation of MR diffusion tensor imaging parameters with ASIA motor scores in hemorrhagic and nonhemorrhagic acute spinal cord injury.

This study investigated correlations between American Spinal Injury Association (ASIA) clinical injury motor scores in patients with traumatic cervical cord injury and magnetic resonance (MR) diffusion tensor imaging (DTI) parameters. Conventional imaging and DTI were performed to evaluate 25 patients (age, 39.7±13.9 years; 4 women, 21 men) with blunt spinal cord injury and 11 volunteers (age, 31.5±10.7 years; 3 women, 8 men). Cord contusions were hemorrhagic (HC) in 13 and non-hemorrhagic (NHC) in 12 patients. The spinal cord was divided into three regions to account for spatial and pathological variation in DTI parameters. Comparisons of regional and injury site mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity ( λ(⊥)), and longitudinal diffusivity ( λ(‖)) were made with control subjects. ASIA motor scores were correlated with DTI using linear regression analysis. HC and NHC patients showed significant reduction (p<0.001) in MD and λ(‖) in all three regions. At the injury site, significant decreases in FA and λ(‖) were seen for both injury groups (p<0.001). λ(⊥) values were significantly increased only for patients with NHC (p<0.05). Significant reduction in FA and λ(‖) (p<0.0001) was observed at the whole cord level between the injured (NH and NHC) and control groups. Within the NHC group, strong correlations were observed between ASIA motor scores and average MD, FA, λ(⊥), and λ(‖) at the injury site. However, no correlation was observed within the HC group between any of the DTI parameters and ASIA motor scores. DTI parameters reflect the severity of spinal cord injury and correlate well with ASIA motor scores in patients with NHC.

Predictors of outcome in acute traumatic central cord syndrome due to spinal stenosis.

OBJECT: the objective of this study was to elucidate the relationship between admission demographic data, validated injury severity measures on imaging studies, and clinical indicators on the American Spinal Injury Association (ASIA) motor score, Functional Independence Measure (FIM), manual dexterity, and dysesthetic pain at least 12 months after surgery for acute traumatic central cord syndrome (ATCCS) due to spinal stenosis. METHODS: over a 100-month period (January 2000 to April 2008), of 211 patients treated for ATCCS, 59 cases were due to spinal stenosis, and these patients underwent surgical decompression. Five of these patients died, 2 were lost to follow-up, 10 were not eligible for the study, and the remaining 42 were followed for at least 12 months. RESULTS: in the cohort of 42 patients, mean age was 58.3 years, 83% of the patients were men, and 52.4% of the accidents were due to falls. Mean admission ASIA motor score was 63.8 (upper extremities score, 25.8 and lower extremities score, 39.8), the spinal cord was most frequently compressed at skeletal segments C3-4 and C4-5 (71%), mean midsagittal diameter at the point of maximum compression was 5.6 mm, maximum canal compromise (MCC) was 50.5%, maximum spinal cord compression was 16.5%, and length of parenchymal damage on T2-weighted MR imaging was 29.4 mm. Time after injury until surgery was within 24 hours in 9 patients, 24-48 hours in 10 patients, and more than 48 hours in 23 patients. At the 1-year follow-up, the mean ASIA motor score was 94.1 (upper extremities score, 45.7 and lower extremities score, 47.6), FIM was 111.1, manual dexterity was 64.4% of baseline, and pain level was 3.5. Stepwise regression analysis of 10 independent variables indicated significant relationships between ASIA motor score at follow-up and admission ASIA motor score (p = 0.003), MCC (p = 0.02), and midsagittal diameter (p = 0.02); FIM and admission ASIA motor score (p = 0.03), MCC (p = 0.02), and age (p = 0.02); manual dexterity and admission ASIA motor score (p = 0.0002) and length of parenchymal damage on T2-weighted MR imaging (p = 0.002); and pain level and age (p = 0.02) and length of parenchymal lesion on T2-weighted MR imaging (p = 0.04). CONCLUSIONS: the main indicators of long-term ASIA motor score, FIM, manual dexterity, and dysesthetic pain were admission ASIA motor score, midsagittal diameter, MCC, length of parenchymal damage on T2-weighted MR imaging, and age, but different domains of outcome were determined by different predictors.

Critical computed tomographic diagnostic criteria for frontal sinus fractures.

PURPOSE: Diagnosis and treatment of frontal sinus fractures (FSFs) have progressed over the previous 30 years. Despite advances in computed tomography, there is no current diagnostic uniformity with regard to classification and treatment. We developed a statistically valid treatment protocol for FSFs based on injury pattern, nasofrontal outflow tract (NFOT) injury, and complication(s). These data outlined predictable injury patterns based on specific computed tomographic findings critical to the diagnosis and ultimate treatment of this potentially fatal injury. MATERIALS AND METHODS: A retrospective review was conducted on patients with FSF from 1979 to 2005 under institutional review board approval. All computed tomographic scans were reviewed by the authors and fractures categorized by location, displacement, comminution, and degree of NFOT injury. RESULTS: One thousand ninety-seven patients with FSF were identified, 87 expired and 153 had inadequate data, leaving a group of 857 patients. Simultaneous displacement of anterior-posterior tables constituted the largest group (38.4%). NFOT injury occurred in most patients (70.7%) and was strongly associated with anterior (92%) and posterior (88%) table involvement (comminuted 98%). Sixty-seven percent of patients with NFOT injury had obstruction. Five hundred four patients (59.6%) had surgery with 10.4% complications and 353 patients were observed with 3.1% complications. All but 1 patient with complications had NFOT injury (98.5%). CONCLUSIONS: Predictable patterns of injury based on specific computed tomographic data play a pivotal role in classification and surgical management of potentially fatal frontal sinus injuries. Radiologic diagnosis of NFOT injury in FSFs, particularly obstruction, plays a decisive role in surgical planning.