NEXUS Chest Research Articles

Screening performance of the chest X-ray in adult blunt trauma evaluation: Is it effective and what does it miss?

Although chest x-ray (CXR) is often used as a screening tool for thoracic injury in adult blunt trauma assessment, its screening performance is unclear. Using chest CT as the referent standard, we sought to determine the screening performance of CXR for injury. We analyzed data from the NEXUS Chest CT study, in which we prospectively enrolled blunt trauma patients older than 14 years who received chest imaging as part of their evaluation at nine level I trauma centers. For this analysis, we included patients who had both CXR and chest CT. We used CT as the referent standard and categorized injuries as clinically major or minor according to an a priori expert panel classification. Of 11,477 patients enrolled, 4501 had both CXR and chest CT; 1496 (33.2%) were found to have injury, of which 256 (17%) were classified as major injury. CXR missed injuries in 818 patients (54.7%), of which 63 (7.7%) were classified as major injuries. For injuries of major clinical significance, CXR had a sensitivity of 75.4% (95% confidence interval [CI] 69.6-80.4%), specificity of 86.2% (95% CI 85.1-87.2%), negative predictive value of 98.3 (95%CI 97.9-98.6%), and positive predictive value of 24.7 (95%CI 22.9-26.7%). For any injury CXR had a sensitivity of 45.3% (95% CI 42.8-47.9%), specificity of 96.6% (95% CI 95.9-97.2%), negative predictive value of 78% (95% CI 77.2-78.8%), and positive predictive value of 86.9% (95% CI 84.5-89.0%). The most common missed major injuries were pneumothorax (30/185; 16.2%), spinal fractures (19/39; 48.7%), and hemothorax (8/70; 11.4%). The most common missed minor injuries were rib fractures (381/836; 45.6%), pulmonary contusion (203/462; 43.9%), and sternal fractures (153/229; 66.8%). When used alone, without other trauma screening criteria, CXR has poor screening performance for blunt thoracic injury.

Thoracic Trauma

More than 85% of blunt and penetrating trauma to the thorax results in injury to the lungs or ribs. Among civilians, blunt trauma is the most common mechanism, while penetrating trauma is the most common among military sectors. This review describes the assessment and stabilization, diagnosis, treatment and disposition, and outcomes of thoracic trauma. Videos shows the “lung point” sign on M-mode and two-dimensional ultrasonography, and a transthoracic echocardiogram clip of pericardial clot and tamponade due to a gunshot wound. Figures show a sonogram showing the “lung point sign”, a chest x-ray and computed tomographic scan demonstrating right-sided hemothorax in a patient with a right chest stab wound, and a three-dimensional computed tomographic scan and chest x-ray of a blunt trauma patient with displaced fractures of the left lateral sixth to ninth ribs. Tables list types of injuries, NEXUS chest decision instrument imaging criteria, level 2 evidence-based recommendations for the management of pulmonary contusion and flail chest by the Eastern Association for the Surgery of Trauma, Eastern Association for the Surgery of Trauma practice guidelines for managing issues with pulmonary contusion and flail chest, and the Vancouver simplified and University of Washington grading systems for blunt aortic injury. This review contains 2 videos, 4 highly rendered figures, 10 tables, and 94 references.

Thoracic Spine Fracture in the Panscan Era

In the current era of frequent chest computed tomography (CT) for adult blunt trauma evaluation, many minor injuries are diagnosed, potentially rendering traditional teachings obsolete. We seek to update teachings in regard to thoracic spine fracture by determining how often such fractures are observed on CT only (ie, not visualized on preceding trauma chest radiograph), the admission rate, mortality, and hospital length of stay of thoracic spine fracture patients, and how often thoracic spine fractures are clinically significant. This was a preplanned analysis of prospectively collected data from the NEXUS Chest CT study conducted from 2011 to 2014 at 9 Level I trauma centers. The inclusion criteria were older than 14 years, blunt trauma occurring within 6 hours of emergency department (ED) presentation, and chest imaging (radiography, CT, or both) during ED evaluation. Of 11,477 enrolled subjects, 217 (1.9%) had a thoracic spine fracture; 181 of the 198 thoracic spine fracture patients (91.4%) who had both chest radiograph and CT had their thoracic spine fracture observed on CT only. Half of patients (49.8%) had more than 1 level of thoracic spine fracture, with a mean of 2.1 levels (SD 1.6 levels) of thoracic spine involved. Most patients (62%) had associated thoracic injuries. Compared with patients without thoracic spine fracture, those with it had higher admission rates (88.5% versus 47.2%; difference 41.3%; 95% confidence interval 36.3% to 45%), higher mortality (6.3% versus 4.0%; difference 2.3%; 95% confidence interval 0 to 6.7%), and longer length of stay (median 9 versus 6 days; difference 3 days; P<.001). However, thoracic spine fracture patients without other thoracic injury had mortality similar to that of patients without thoracic spine fracture (4.6% versus 4%; difference 0.6%; 95% confidence interval -2.5% to 8.6%). Less than half of thoracic spine fractures (47.4%) were clinically significant: 40.8% of patients received thoracolumbosacral orthosis bracing, 10.9% had surgery, and 3.8% had an associated neurologic deficit. Thoracic spine fracture is uncommon. Most thoracic spine fractures are associated with other thoracic injuries, andmortality is more closely related to these other injuries than to the thoracic spine fracture itself. More than half of thoracic spine fractures are clinically insignificant; surgical intervention is uncommon and neurologic injury is rare.

Blunt Traumatic Aortic Injury in the Pan-scan Era.

In the era of frequent head-to-pelvis computed tomography (CT) for adult blunt trauma evaluation, we sought to update teachings regarding aortic injury by determining 1) the incidence of aortic injury; 2) the proportion of patients with isolated aortic injury (without other concomitant thoracic injury); 3) the clinical implications of aortic injury (hospital mortality, length of stay [LOS], and rate of surgical interventions); and 4) the screening value of traditional risk factors/markers (such as high-energy mechanism and widened mediastinum on chest x-ray [CXR]) for aortic injury, compared to newer criteria from the recently developed NEXUS Chest CT decision instrument (DI). We conducted a preplanned analysis of patients prospectively enrolled in the NEXUS Chest studies at 10 Level I trauma centers with the following inclusion criteria: age > 14years, blunt trauma within 6hours of ED presentation, and receiving chest imaging duringED trauma evaluation. Of 24,010 enrolled subjects, 42 (0.17%, 95% confidence interval [CI]= 0.13% to 0.24%) had aortic injury. Most patients (79%, 95% CI= 64% to 88%) had an associated thoracic injury, with rib fractures, pneumothorax/hemothorax, and pulmonary contusion occurring most frequently. Compared to patients without aortic injury this cohort had similar mortality (9.5%, 95% CI= 3.8% to 22.1% vs. 5.8%, 95% CI= 5.4% to 6.3%), longer median hospital LOS (11days vs. 3days, p<0.01), and higher median Injury Severity Score (29 vs. 5, p<0.001). High-energy mechanism and widened mediastinum on CXR had low sensitivity for aortic injury (76% [95% CI= 62% to 87%] and 33% [95% CI= 21% to 49%], respectively), compared to the NEXUS Chest CT DI (sensitivity 100% [95% CI= 92% to 100%]). Aortic injury is rare in adult ED blunt trauma patients who survive to receive imaging. Most ED aortic injury patients have associated thoracic injuries and survive to hospital discharge.Widened mediastinum on CXR and high-energy mechanism have relatively low screening sensitivity for aortic injury, but the NEXUS Chest DI detected all cases.

An impact analysis of the NEXUS Chest CT clinical decision rule

BackgroundThe NEXUS Chest CT clinical decision rules (CDRs) have been proposed to safely guide selective chest CT use in blunt trauma evaluation. We conducted a cost-effectiveness analysis of the NEXUS Chest CT CDR to determine its impact on missed injuries, cost, and radiation exposure. MethodsWe constructed a decision model comparing two strategies: implementation of the NEXUS Chest CDR vs. usual care in the evaluation of adults with blunt trauma. We derived probabilities, clinical outcomes, effective radiation dose (ERD) from the NEXUS Chest CT validation cohort and costs from the Charge-master at the primary study site. Our primary outcomes were cost and effective radiation dose (ERD) per missed clinically significant injury (CSI). ResultsUsing a hypothetical cohort of 1000 adults with blunt chest trauma in each arm, the base case model projected that the implementation of the CDR would result in 161 fewer chest CTs, 0.08 additional missed CSIs, a cost savings of $136,432 and a decrease in 1435 mSv, as compared to Usual Care. To detect one additional CSI, the Usual Care strategy would require 2015 more chest CTs with a cost of $1.8 million and 17,934 mSv more radiation. ConclusionsCompared to usual care, implementation of the NEXUS Chest CT Major CDR in the evaluation of adults with blunt trauma would greatly reduce CT associated costs and radiation exposure with a slight increased risk of missed CSIs.

NEXUS Chest CT clinical decision rules save CT-related costs

NEXUS Chest CT clinical decision rules save CT-related costs

Comparison of Diagnostic Accuracy of NEXUS Chest and Thoracic Injury Rule-Out Criteria in Patients with Blunt Trauma; A Cross-Sectional Study

Background: Blunt chest trauma is the third most important injury in patients with multiple trauma, thus the appropriate diagnosis is critical. Although chest X-rays (CXRs) are the most common diagnostic method, the physician should detect the imaging necessity and modality. Accordingly, NEXUS chest and thoracic injury rule-out criteria (TIRC) have been developed to prevent unnecessary radiographs in traumatized patients. Objectives: In this study, the diagnostic accuracy of these two guidelines was compared in patients with multiple trauma. Methods: In this cross-sectional study, eligible patients with chest blunt trauma, who referred to the Emergency Department of Imam Hossein Hospital from July 2016 to March 2018, were recruited. Demographic data, trauma and clinical information, and radiographic reports were recorded and the necessity of CXR was determined based on NEXUS chest and TIRC. Finally, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were also calculated for NEXUS chest and TIRC. Results: In this study, 1925 patients with a mean age of 43.7 ± 9.16 years were evaluated (55% male). The sensitivity, specificity, PPV, NPV of TIRC in the diagnosis of traumatic chest injury were 93.6%, 84.9%, 24.03%, and 99.6%, respectively, and those of NEXUS in the diagnosis of traumatic chest injuries were 97.84%, 51.80%, 93.43%, and 99.79%, respectively. There was no significant difference in diagnostic accuracy between TIRC and NEXUS chest models. Conclusions: This study showed that NEXUS chest and TIRC have equal values in predicting traumatized chest injuries. Parameters of TIRC are easily measurable in ED and do not require subjective assessments, such as mechanisms and velocity of trauma or fall height. Therefore, the TIRC model seems to be a better tool than NEXUS in detecting injury to the chest and reducing the risk of radiation exposure.

Pneumothorax and Hemothorax in the Era of Frequent Chest Computed Tomography for the Evaluation of Adult Patients With Blunt Trauma

Although traditional teachings in regard to pneumothorax and hemothorax generally recommend chest tube placement and hospital admission, the increasing use of chest computed tomography (CT) in blunt trauma evaluation may detect more minor pneumothorax and hemothorax that might indicate a need to modify these traditional practices. We determine the incidence of pneumothorax and hemothorax observed on CT only and the incidence of isolated pneumothorax and hemothorax (pneumothorax and hemothorax occurring without other thoracic injuries), and describe the clinical implications of these injuries. This was a planned secondary analysis of 2 prospective, observational studies of adult patients with blunt trauma, NEXUS Chest (January 2009 to December 2012) and NEXUS Chest CT (August 2011 to May 2014), set in 10 Level I US trauma centers. Participants' inclusion criteria were older than 14 years, presentation to the emergency department (ED) within 6 hours of blunt trauma, and receipt of chest imaging (chest radiograph, chest CT, or both) during their ED evaluation. Exposure(s) (for observational studies) were that patients had trauma and chest imaging. Primary measures and outcomes included the incidence of pneumothorax and hemothorax observed on CT only versus on both chest radiograph and chest CT, the incidence of isolated pneumothorax and hemothorax (pneumothorax and hemothorax occurring without other thoracic injuries), and admission rates, hospital length of stay, mortality, and frequency of chest tube placement for these injuries. Of 21,382 enrolled subjects, 1,064 (5%) had a pneumothorax and 384 (1.8%) had a hemothorax. Of the 8,661 patients who received both a chest radiograph and a chest CT, 910 (10.5%) had a pneumothorax, with 609 (67%) observed on CT only; 319 (3.7%) had a hemothorax, with 254 (80%) observed on CT only. Of 1,117 patients with pneumothorax, hemothorax, or both, 108 (10%) had isolated pneumothorax or hemothorax. Patients with pneumothorax observed on CT only had a lower chest tube placement rate (30% versus 65%; difference in proportions [Δ] -35%; 95% confidence interval [CI] -28% to 42%), admission rate (94% versus 99%; Δ 5%; 95% CI 3% to 8%), and median length of stay (5 versus 6 days; difference 1 day; 95% CI 0 to 2 days) but similar mortality compared with patients with pneumothorax observed on chest radiograph and CT. Patients with hemothorax observed on CT had only a lower chest tube placement rate (49% versus 68%; Δ -19%; 95% CI -31% to -5%) but similar admission rate, mortality, and median length of stay compared with patients with hemothorax observed on chest radiograph and CT. Compared with patients with other thoracic injury, those with isolated pneumothorax or hemothorax had a lower chest tube placement rate (20% versus 43%; Δ -22%; 95% CI -30% to -13%), median length of stay (4 versus 5 days; difference -1 day; 95% CI -3 to 1 days), and admission rate (44% versus 97%; Δ -53%; 95% CI -62% to -43%), with an admission rate comparable to that of patients without pneumothorax or hemothorax (49%). Under current imaging protocols for adult blunt trauma evaluation, most pneumothoraces and hemothoraces are observed on CT only and few occur as isolated thoracic injury. The clinical implications (admission rates and frequency of chest tube placement) of pneumothorax and hemothorax observed on CT only and isolated pneumothorax or hemothorax are lower than those of patients with pneumothorax and hemothorax observed on chest radiograph and CT and of those who have other thoracic injury, respectively.

Thoracic injury rule out criteria and NEXUS chest in predicting the risk of traumatic intra-thoracic injuries: A diagnostic accuracy study

IntroductionThis study aimed to compare the diagnostic accuracy of NEXUS chest and Thoracic Injury Rule out criteria (TIRC) models in predicting the risk of intra-thoracic injuries following blunt multiple trauma. MethodsIn this diagnostic accuracy study, using the 2 mentioned models, blunt multiple trauma patients over the age of 15 years presenting to emergency department were screened regarding the presence of intra-thoracic injuries that are detectable via chest x-ray and screening performance characteristics of the models were compared. ResultsIn this study, 3118 patients with the mean (SD) age of 37.4 (16.9) years were studied (57.4% male). Based on TIRC and NEXUS chest, respectively, 1340 (43%) and 1417 (45.4%) patients were deemed in need of radiography performance. Sensitivity, specificity, and positive and negative predictive values of TIRC were 98.95%, 62.70%, 21.19% and 99.83%. These values were 98.61%, 59.94%, 19.97% and 99.76%, for NEXUS chest, respectively. Accuracy of TIRC and NEXUS chest models were 66.04 (95% CI: 64.34–67.70) and 63.50 (95% CI: 61.78–65.19), respectively. ConclusionTIRC and NEXUS chest models have proper and similar sensitivity in prediction of blunt traumatic intra-thoracic injuries that are detectable via chest x-ray. However, TIRC had a significantly higher specificity in this regard.

Prevalence and Diagnostic Performance of Isolated and Combined NEXUS Chest CT Decision Criteria.

The use of chest computed tomography (CT) to evaluate emergency department patients with adult blunt trauma is rising. The NEXUS Chest CT decision instruments are highly sensitive identifiers of adult blunt trauma patients with thoracic injuries. However, many patients without injury exhibit one of more of the criteria so cannot be classified "low risk." We sought to determine screening performance of both individual and combined NEXUS Chest CT criteria as predictors of thoracic injury to inform chest CT imaging decisions in "non-low-risk" patients. This was a secondary analysis of data on patients in the derivation and validation cohorts of the prospective, observational NEXUS Chest CT study, performed September 2011 to May 2014 in 11 Level I trauma centers. Institutional review board approval was obtained at all study sites. Adult blunt trauma patients receiving chest CT were included. The primary outcome was injury and major clinical injury prevalence and screening performance in patients with combinations of one, two, or three of seven individual NEXUS Chest CT criteria. Across the 11 study sites, rates of chest CT performance ranged from 15.5% to 77.2% (median = 43.6%). We found injuries in 1,493/5,169 patients (28.9%) who had chest CT; 269 patients (5.2%) had major clinical injury (e.g., pneumothorax requiring chest tube). With sensitivity of 73.7 (95% confidence interval [CI] = 68.1 to 78.6) and specificity of 83.9 (95% CI = 83.6 to 84.2) for major clinical injury, abnormal chest-x-ray (CXR) was the single most important screening criterion. When patients had only abnormal CXR, injury and major clinical injury prevalences were 60.7% (95% CI = 52.2% to 68.6%) and 12.9% (95% CI = 8.3% to 19.4%), respectively. Injury and major clinical injury prevalences when any other single criterion alone (other than abnormal CXR) was present were 16.8% (95% CI = 15.2% to 18.6%) and 1.1% (95% CI = 0.1% to 1.8%), respectively. Injury and major clinical injury prevalences among patients when two and three criteria (not abnormal CXR) were present were 25.5% (95% CI = 23.1% to 28.0%) and 3.2% (95% CI = 2.3% to 4.4%) and 34.9% (95% CI = 31.0% to 39.0%) and 2.7% (95% CI = 1.6% to 4.5%), respectively. We recommend that clinicians check for the six clinical NEXUS Chest CT criteria and review the CXR (if obtained). If patients have one clinical criterion (other than abnormal CXR), they will have a very low risk of clinically major injury. We recommend that clinicians discuss the potential risks and benefit of chest CT in these cases. The risks of injury and major clinical injury rise incrementally with more criteria, rendering the risk/benefit ratio toward performing CT in most cases. If the patient has an abnormal CXR, the risks of major clinical injury and minor injury are considerably higher than with the other criteria-chest CT may be indicated in cases requiring greater anatomic detail and injury characterization.

Individualizing Decision Making About Imaging for Chest Trauma

Decision rules typically take the form of “you don't have to do X if the patient meets Y criteria.” This holds for the NEXUS chest rule, which requires absence of all seven of its criteria to forgo imaging, and has a 99.9% negative predictive value for excluding major thoracic injury. The downside is that such rules often have …

Derivation and validation of two decision instruments for selective chest CT in blunt trauma: a multicenter prospective observational study (NEXUS Chest CT).

BackgroundUnnecessary diagnostic imaging leads to higher costs, longer emergency department stays, and increased patient exposure to ionizing radiation. We sought to prospectively derive and validate two decision instruments (DIs) for selective chest computed tomography (CT) in adult blunt trauma patients.Methods and FindingsFrom September 2011 to May 2014, we prospectively enrolled blunt trauma patients over 14 y of age presenting to eight US, urban level 1 trauma centers in this observational study. During the derivation phase, physicians recorded the presence or absence of 14 clinical criteria before viewing chest imaging results. We determined injury outcomes by CT radiology readings and categorized injuries as major or minor according to an expert-panel-derived clinical classification scheme. We then employed recursive partitioning to derive two DIs: Chest CT-All maximized sensitivity for all injuries, and Chest CT-Major maximized sensitivity for only major thoracic injuries (while increasing specificity). In the validation phase, we employed similar methodology to prospectively test the performance of both DIs.We enrolled 11,477 patients—6,002 patients in the derivation phase and 5,475 patients in the validation phase. The derived Chest CT-All DI consisted of (1) abnormal chest X-ray, (2) rapid deceleration mechanism, (3) distracting injury, (4) chest wall tenderness, (5) sternal tenderness, (6) thoracic spine tenderness, and (7) scapular tenderness. The Chest CT-Major DI had the same criteria without rapid deceleration mechanism. In the validation phase, Chest CT-All had a sensitivity of 99.2% (95% CI 95.4%–100%), a specificity of 20.8% (95% CI 19.2%–22.4%), and a negative predictive value (NPV) of 99.8% (95% CI 98.9%–100%) for major injury, and a sensitivity of 95.4% (95% CI 93.6%–96.9%), a specificity of 25.5% (95% CI 23.5%–27.5%), and a NPV of 93.9% (95% CI 91.5%–95.8%) for either major or minor injury. Chest CT-Major had a sensitivity of 99.2% (95% CI 95.4%–100%), a specificity of 31.7% (95% CI 29.9%–33.5%), and a NPV of 99.9% (95% CI 99.3%–100%) for major injury and a sensitivity of 90.7% (95% CI 88.3%–92.8%), a specificity of 37.9% (95% CI 35.8%–40.1%), and a NPV of 91.8% (95% CI 89.7%–93.6%) for either major or minor injury. Regarding the limitations of our work, some clinicians may disagree with our injury classification and sensitivity thresholds for injury detection.ConclusionsWe prospectively derived and validated two DIs (Chest CT-All and Chest CT-Major) that identify blunt trauma patients with clinically significant thoracic injuries with high sensitivity, allowing for a safe reduction of approximately 25%–37% of unnecessary chest CTs. Trauma evaluation protocols that incorporate these DIs may decrease unnecessary costs and radiation exposure in the disproportionately young trauma population.

Sternal fracture in the age of pan-scan

Study objectiveWidespread chest CT use in trauma evaluation may increase the diagnosis of minor sternal fracture (SF), making former teaching about SF obsolete. We sought to determine: (1) the frequency with which SF patients are diagnosed by CXR versus chest CT under current imaging protocols, (2) the frequency of surgical procedures related to SF diagnosis, (3) SF patient mortality and hospital length of stay comparing patients with isolated sternal fracture (ISF) and sternal fracture with other thoracic injury (SFOTI), and (4) the frequency and yield of cardiac contusion (CC) workups in SF patients. MethodsWe analyzed charts and data of all SF patients enrolled from January 2009 to May 2013 in the NEXUS Chest and NEXUS Chest CT studies, two multi-centre observational cohorts of blunt trauma patients who received chest imaging for trauma evaluation. ResultsOf the 14,553 patients in the NEXUS Chest and Chest CT cohorts, 292 (2.0%) were diagnosed with SF, and 94% of SF were visible on chest CT only. Only one patient (0.4%) had a surgical procedure related to SF diagnosis. Cardiac contusion was diagnosed in 7 (2.4%) of SF patients. SF patient mortality was low (3.8%) and not significantly different than the mortality of patients without SF (3.1%) [mean difference 0.7%; 95% confidence interval (CI) −1.0 to 3.5%]. Only 2 SF patient deaths (0.7%) were attributed to a cardiac cause. SFOTI patients had longer hospital stays but similar mortality to patients with ISF (mean difference 0.8%; 95% CI −4.7% to 12.0). ConclusionsMost SF are seen on CT only and the vast majority are clinically insignificant with no change in treatment and low associated mortality. Workup for CC in SF patients is a low-yield practice. SF diagnostic and management guidelines should be updated to reflect modern CT-driven trauma evaluation protocols.

NEXUS Chest: Validation of a Decision Instrument for Selective Chest Imaging in Blunt Trauma: Rodriguez RM, Anglin D, Langdorf MI, et al. JAMA Surg 2013;148:940–6.

NEXUS Chest: Validation of a Decision Instrument for Selective Chest Imaging in Blunt Trauma: Rodriguez RM, Anglin D, Langdorf MI, et al. JAMA Surg 2013;148:940–6.

NEXUS Chest

Chest radiography (chest x-ray [CXR] and chest computed tomography [CT]) is the most common imaging in blunt trauma evaluation. Unnecessary trauma imaging leads to greater costs, emergency department time, and patient exposure to ionizing radiation. OBJECTIVE To validate our previously derived decision instrument (NEXUS Chest) for identification of blunt trauma patients with very low risk of thoracic injury seen on chest imaging (TICI). We hypothesized that NEXUS Chest would have high sensitivity (>98%) for the prediction of TICI and TICI with major clinical significance. From December 2009 to January 2012, we enrolled blunt trauma patients older than 14 years who received chest radiography in this prospective, observational, diagnostic decision instrument study at 9 US level I trauma centers. Prior to viewing radiographic results, physicians recorded the presence or absence of the NEXUS Chest 7 clinical criteria (age >60 years, rapid deceleration mechanism, chest pain, intoxication, abnormal alertness/mental status, distracting painful injury, and tenderness to chest wall palpation). Thoracic injury seen on chest imaging was defined as pneumothorax, hemothorax, aortic or great vessel injury, 2 or more rib fractures, ruptured diaphragm, sternal fracture, and pulmonary contusion or laceration seen on radiographs. An expert panel generated an a priori classification of clinically major, minor, and insignificant TICIs according to associated management changes. Of 9905 enrolled patients, 43.1% had a single CXR, 42.0% had CXR and chest CT, 6.7% had CXR and abdominal CT (without chest CT), 5.5% had multiple CXRs without CT, and 2.6% had chest CT alone in the emergency department. The most common trauma mechanisms were motorized vehicle crash (43.9%), fall (27.5%), pedestrian struck by motorized vehicle (10.7%), bicycle crash (6.3%), and struck by blunt object, fists, or kicked (5.8%). Thoracic injury seen on chest imaging was seen in 1478 (14.9%) patients with 363 (24.6%) of these having major clinical significance, 1079 (73.0%) minor clinical significance, and 36 (2.4%) no clinical significance. NEXUS Chest had a sensitivity of 98.8% (95% CI, 98.1%-99.3%), a negative predictive value of 98.5% (95% CI, 97.6%.6-99.1%), and a specificity of 13.3% (95% CI, 12.6%-14.1%) for TICI. The sensitivity and negative predictive value for TICI with clinically major injury were 99.7% (95% CI, 98.2%-100.0%) and 99.9% (95% CI, 99.4%-100.0%), respectively. We have validated the NEXUS Chest decision instrument, which may safely reduce the need for chest imaging in blunt trauma patients older than 14 years.