Role of CT in excluding major arterial injury after blunt thoracic trauma

The role of CT in the diagnosis of major vascular rupture following blunt decelerating chest trauma is controversial. Its value in excluding major arterial injury has not yet been determined. During a 12-month period we obtained dynamic enhanced thoracic CT studies in 20 patients with blunt decelerating thoracic trauma who had abnormal or equivocal mediastinal contours on chest radiographs. In all cases diagnosis was confirmed by either digital subtraction (18 patients) or conventional thoracic angiography (two patients). CT scans showed evidence of direct aortic injury in three patients and evidence of mediastinal hematoma in five others. Four of these eight patients had major arterial injury verified angiographically and at surgery. In two patients the CT scan was considered equivocal; both patients had normal thoracic angiograms. CT excluded direct vascular injury or mediastinal hematoma in 10 patients. All 10 had normal thoracic angiograms. This preliminary study suggests that, in patients sustaining blunt decelerating thoracic trauma, thoracic CT may be more valuable than chest radiography in excluding major vascular injury and, in some cases, may reduce the need for thoracic angiography.     

Blunt thoracic aortic injury in children

Thoracic aortic injury (TAI) in children secondary to blunt chest trauma is rare and less well documented than TAI in adults. To further establishe the incidence and radiographic manifestations of this severe injury, we reviewed our experimence with TAI in children over an 8-year period. We performed a computer search from the Trauma Registry at our level I trauma center for all cases of TAI among patients 16 years of age or younger who were admitted after sustaining blunt chest trauma between August 1984 and September 1992. We reviewed our records of all thoracic aortograms performed on children for blunt trauma during this same time period. Indication for angiography was determined by review of chest radiographs and medical records of all patients who underwent thoracic aortography. We reviewed medical records and all available chest radiographs, computed tomography (CT) examinations, and thoracic aortograms of children diagnosed with TAI. Of 308 children admitted with blunt chest trauma, 26 (8.4%) underwent angiography to exclude aortic or great vessel injury. Of these 26 patients, three (11.5%) were diagnosed with TAI, and one patient demonstrated a traumatic pseudoaneurysm of the proximal left subclavian artery. The incidence of TAI among children who sustained blunt chest trauma was 1.0% in our series. All three patients with TAI in our series were male, ages 10–12 (mean: 11 years). Chest radiographs on two of the patients with TAI revealed mediastinal widening, ill-defined aortic outline, shift of the trachea and nasogastric tube, and depression of the left main stem bronchus. The chest radiograph in one patient with TAI was technically inadequate. CT demonstrated abnormalities in two patients. Angiographic findings were similar to those seen in adults. TAI in children is rare, occurring in 1% of children sustaining blunt chest trauma in our series. Our findings support previous reports that the plain film, CT, and angiographic findings with this injury resemble those found in adults.     

Role of contrast-enhanced helical CT in the evaluation of acute thoracic aortic injuries after blunt chest trauma

The purpose of this retrospective study was to determine the value of contrast-enhanced helical CT for detecting and managing acute thoracic aortic injury (ATAI). Between June 1995 and February 2000, 1419 consecutive chest CT examinations were performed in the setting of major blunt trauma. The following CT findings were considered indicative of ATAI: intimal flap; pseudoaneurysm; contour irregularity; lumen abnormality; and extravasation of contrast material. On the basis of these direct findings no further diagnostic investigations were performed. Isolated mediastinal hematoma on CT scans was considered an indirect sign of ATAI: In these cases, thoracic aortography was performed even if CT indicated normal aorta. Seventy-seven patients had abnormal CT scans: Among the 23 patients with direct CT signs, acute thoracic aortic injuries was confirmed at thoracotomy in 21. Two false-positive cases were observed. The 54 remaining patients had isolated mediastinal hematoma without aortic injuries at CT and corresponding negative angiograms. The 1342 patients with negative CT scans were included in the 8-month follow-up program and did not show any adverse sequela based on clinical and radiographic criteria. Contrast-enhanced helical CT has a critical role in the exclusion of thoracic aortic injuries in patient with major blunt chest trauma and prevents unnecessary thoracic aortography. Direct CT signs of ATAI do not require further diagnostic investigations to confirm the diagnosis: Isolated aortic bands or contour vessel abnormalities should be first considered as possible artifacts or related to non-traumatic etiologies especially when mediastinal hematoma is absent. In cases of isolated mediastinal hematoma other possible sources of bleeding should be considered before directing patients to thoracic aortography.     

Computed tomography evaluation of traumatic rupture of the thoracic aorta: an outcome study.

OBJECTIVE: [corrected] To assess the long-term outcome of blunt trauma patients with suspected thoracic aortic or great vessel injury that was evaluated with contrast-enhanced chest computed tomography (CT). METHODS: We studied the outcome of 278 consecutive patients who received contrast-enhanced CT for blunt chest trauma with computerized searches of the regional trauma database, hospital medical records, universal government medical coverage plan billing records, and regional vital statistics databases. Data retrieved included patient demographics, mechanism of injury, status of the aorta and proximal great vessels at contrast-enhanced CT, hospital discharge diagnoses, and outpatient procedural billings with specific attention to aortic or great vessel injury. Median follow-up was 615 days following the traumatic event. RESULTS: Six subjects demonstrated direct signs of aortic or proximal great vessel injury on contrast-enhanced chest CT, as follows: aortic pseudoaneurysm and intimal flap (n = 4), carotid artery dissection (n = 1), and aortic dissection (n = 1). All were surgically treated, except the patient with aortic dissection, who was treated medically. In the other subjects, contrast-enhanced CT was negative (n = 230) or showed isolated mediastinal hematoma (n = 42). The computerized searches of the medical databases showed that none of these 272 subjects had procedures for, or died from, aortic or great vessel injury during the follow-up period. CONCLUSION: Computerized searches of medical databases found no evidence of missed thoracic aortic or proximal great vessel injury in blunt trauma patients who were evaluated with contrast-enhanced chest CT.     

Evaluation of traumatic aortic injury: does dynamic contrast-enhanced CT play a role?

To investigate the value of 5-mm contrast material-enhanced computed tomography (CT) in patients with moderate to low probability of aortic laceration after a substantial deceleration injury, scans were obtained through the upper mediastinum in 160 consecutive patients. Thoracic angiography and aortography were performed in patients with evidence of mediastinal hemorrhage at CT. There was no evidence of mediastinal hemorrhage in 132 patients with normal admission chest radiographs. In the 28 patients with abnormal admission chest radiographs, CT helped exclude mediastinal hemorrhage in 22 patients (78%), and 19 patients (68%) were treated without undergoing angiography. Six patients had mediastinal hematoma at CT. Only one had an aortic laceration at angiography. The authors conclude that 5-mm contrast-enhanced CT can help exclude mediastinal hemorrhage and reduce the angiography rate in low-to-moderate-risk patients with a widened or indeterminate mediastinum. There were no unsuspected cases of mediastinal hemorrhage in patients with normal chest radiographs. Angiography is recommended for patients considered to be at high risk for aortic laceration.     

X-ray computed tomography of thoracic injuries. Apropos of 40 cases]

On chest radiographs, the precise assessment of thoracic injuries consecutive to blunt trauma is often compromised by the nonspecific appearance of many lesions. Furthermore, significant injuries are frequently overlooked. However, the management of the patients with chest trauma is still often based primarily upon clinical and radiographic findings and Computed Tomography (CT) is often performed secondarily on the basis of unexplained clinical signs or suspected radiographic abnormality. Some authors have reported that CT was a highly sensitive method for detecting thoracic lesions frequently not seen or underestimated on conventional supine chest radiographs. However, the value that these new CT findings could have in the therapeutic management of these patients, have not been systematically investigated to our knowledge, except in a limited series suggesting that the course of critically ill patients could be substantially altered after thoracic CT. In order to estimate the role of early CT in the management of patient care, we report the therapeutic consequences of CT findings in forty patients who we report the therapeutic consequences of CT findings in forty patients who had a thoracic CT within few hours following a chest injury. We showed that early thoracic CT scan in patients with blunt trauma detected significantly more lesions than did chest X-Ray and appreciably modified the treatment modalities in 70% of our patients. We then recommend that all the patients admitted in ICU after chest trauma undergo a thoracic CT scan as soon as possible in order to optimize their treatment modalities.     

Value of spiral CT in hemodynamically stable patients following blunt chest trauma

Introduction: Features of spiral CT (SCT) — fast scanning, dynamic injection of contrast allowing optimal vessel opacification, and supplemental multiplanar imaging — promises to provide increased accuracy in the diagnosis of acute and non acute thoracic vascular disease. Recent work demonstrating the cost effective triage of hemodynamically stable patients after blunt chest trauma for angiography based on dynamic CT findings has prompted an investigation into the accuracy of SCT in this clinical setting. Methods: A retrospective review of all patients seen in the emergency department over the period of one year for aortic, thoracic, or blunt chest trauma evaluation was performed (74 patients) and all SCT scans available were reviewed and data reformatted for optimal delineation of pathology using maximum intensity projection and multiplanar reformation. The accuracy and predictive positive and negative values of SCT were calculated with respect to angiography, surgical, and/or clinical follow up evaluation. Results: Twenty three (31%) patients went directly to angiography owing to mediastinal widening on chest film and hemodynamic instability, of which four were positive and required emergent surgery. Seven hemodynamically stable patients (9%) had noncontrast SCT owing to mediastinal widening on chest film, all of which had angiography with none having great vessel trauma. Fourty four hemodynamically stable patients (60%) had contrast enhanced SCT (ceSCT), of which five (11%) were abnormal and underwent angiography, four of these were positive for aortic damage, one for a subclavian artery laceration. Of the remaining 39 patients who had normal ceSCT; five had angiography, all of which were normal. Of the remaining 34 patients that had normal ceSCT none had adverse outcome on clinical follow-up, minimum of 12 months. Conclusion: The predictive positive value for aortic trauma of ceSCT in blunt trauma is 80%, with a predictive negative value of 100%, indicating that it is feasible for SCT to be a first line exam in blunt chest trauma in the future.     

Thoracic aortic rupture: advantages of intraarterial digital subtraction angiography

Sixty-one consecutive patients with blunt thoracic trauma underwent intraarterial digital subtraction angiography (IA-DSA) of the thoracic aorta because of obscuration of the aortic knob or mediastinal widening on chest radiographs. Ten of these patients had aortic ruptures diagnosed by IA-DSA. Digital subtraction aortography proved 100% accurate as indicated by results of surgery, conventional arteriography, serial chest radiography, and clinical follow-up. The method was 50% faster compared with conventional aortography and saved significantly on film costs. The potential for use of smaller caliber catheters and a decrease in contrast requirements also make this method safer than conventional arteriography. We recommend IA-DSA as the procedure of choice when emergency aortography is warranted.     

Gas in the sternoclavicular joints of patients with blunt chest trauma: significance and frequency of CT findings.

OBJECTIVE: In trauma patients, gas (vacuum phenomenon) in the sternoclavicular joints could represent sequelae of significant distraction forces and thus serve as a potential marker for severe intrathoracic injury. We evaluated the significance and frequency of the finding of gas in the sternoclavicular joints on chest CT of patients with blunt trauma. SUBJECTS AND METHODS: We prospectively studied all chest CT examinations performed at our institution over a 14-week period for the finding of gas in the sternoclavicular joints. Chest CT examinations (n = 267) were performed in 234 patients. We excluded data from follow-up CT examinations (n = 33), limiting our evaluation to the initial CT examination for each patient. Of the study population, 103 patients (83 men and 20 women) who ranged in age from 14 to 79 years (mean, 40 years) had sustained blunt chest trauma. For all trauma patients, we recorded the mechanism of injury and the associated thoracic injuries. RESULTS: CT revealed gas in the sternoclavicular joints in 47 patients (21%). Gas was unilateral in 27 patients and bilateral in 20 patients. Sternoclavicular joint gas was seen in 39 (38%) of the 103 trauma patients but was found in only eight (6%) of the 131 nontrauma patients (p < .0001). In the 39 trauma patients with sternoclavicular joint gas, associated thoracic injuries were seen in 17 patients (44%); either a sternal fracture or a retrosternal hematoma was seen in three patients. Radiographically evident thoracic injury was revealed in 20 (31%) of the 64 trauma patients who had no gas in the sternoclavicular joint; however, 10 of these 20 patients had either a sternal fracture or a mediastinal hematoma. CONCLUSION: Although gas in the sternoclavicular joints is more frequently seen in patients with blunt chest trauma than in patients undergoing chest CT for other indications, this finding does not indicate a greater risk of significant mediastinal or thoracic injury.     

Chest injury in children with blunt abdominal trauma: evaluation with CT

One or more significant chest injuries were identified in 62 of 512 children (12%) examined with computed tomography (CT) after blunt abdominal trauma. Thirty-eight percent of all abnormalities identified on CT scans were underestimated or missed on the initial chest radiograph. Pleural and parenchymal abnormalities were missed in 50% and 34% of initial chest radiographs, respectively. Chest injuries occurred more frequently in children less than 7 years of age than in older children (62% vs 38%, P less than .02). Children with chest injuries tended to be more physiologically unstable than children without, as determined with lower (worse) mean trauma scores (P less than .001). Both the presence and severity of chest injuries strongly affected outcome. Mortality was 1.3% in children with no chest injury, 10.8% in children with significant unilateral chest injury, and 40% in children with significant bilateral or mediastinal chest injury (P less than .0001). Significant unsuspected or underestimated thoracic injuries are relatively common in children, and CT scans of the chest obtained while examinations of the upper abdomen are being performed can be helpful in the early recognition of such injuries.     

Lung parenchymal injury and its frequency in blunt thoracic trauma: the diagnostic value of chest radiography and thoracic CT

PURPOSE: The aims of this study were to determine the value of chest radiography in diagnosing lung parenchymal injury in patients with thoracic trauma, and to evaluate the frequency of lung parenchymal injury by using thoracic computed tomography (CT). MATERIALS AND METHODS: Between January 2005 and June 2006, we retrospectively evaluated the anteroposterior chest radiographs and thoracic CTs of 60 patients that presented to our emergency department and were hospitalized due to multi-organ trauma. RESULTS: Chest radiography revealed parenchymal injury in 32 of the patients, while thoracic CT confirmed parenchymal injury in only 27 of these 32 patients. Chest radiographs did not reveal any parenchymal injury in 28 of the patients, whereas thoracic CT detected parenchymal injury in 12 of these 28 patients. Thoracic CT results were accepted as the gold standard in the evaluation of patients with chest trauma and showed that the sensitivity, specificity, positive predictive value, and negative predictive value of chest radiography in determining parenchymal injury were 69%, 76%, 84%, and 57%, respectively. In addition, thoracic CT revealed that 65% of the patients with blunt thoracic trauma suffered parenchymal injury. CONCLUSION: The sensitivity of anteroposterior chest radiography in identifying lung parenchymal injury was low, with a high false negative rate; therefore, we think that early evaluation with thoracic CT is extremely helpful in the diagnosis and treatment of patients with thoracic trauma, adding to the cooperative work that exists between radiologists and emergency physicians.     

Evaluation of the role of chest computed tomography in the management of trauma patients

The role of chest computed tomography (CT) in the management of trauma patients is evolving. The present study reviews the chest radiographic and chest CT findings in a group of trauma patients to determine the clinical impact of findings noted exclusively on chest CT.Fifty-five trauma patients examined with chest radiography and chest CT and whose clinical charts were available for review were retrospectively identified. There were 46 men and 9 women, with a mean age of 39 years. The presence (and size) of pneumothorax, hemothorax, pulmonary contusion, and fractures was tabulated for the chest radiographs and CT scans. The presence of mediastinal widening on chest radiographs and all mediastinal findings on CT were noted. The results of aortography, when applicable, were correlated. The clinical charts were reviewed to assess the impact of CT findings on patient management.Pneumothorax (P<0.05), hemothorax (P<0.05), pulmonary contusions, and fractures were noted more frequently on chest CT than on chest radiography. However, clinical management was affected in only three (5%) of these patients. Chest CT findings related to the mediastinum affected patient management in 13 (24%) patients. CT obviated the need for aortography in 7 of 10 patients with mediastinal widening on chest radiographs. Six other patients had aortography, four for mediastinal hematoma with a normal-appearing aorta on contrast medium-enhanced CT, and two for mediastinal hematoma and aortic injury on CT.Despite detection of significantly more pneumothoraces and hemothoraces on chest CT, clinical management was affected in only a small minority (5%) of cases. CT did prove useful in evaluating the mediastinum, obviating the need for aortography in 7 of 10 patients with a widened mediastinum on chest radiography and accurately diagnosing the presence and site of aortic injury in the two patients with that diagnosis.     

Periaortic hematoma at diaphragmatic crura at helical CT: sign of blunt aortic injury in patients with mediastinal hematoma

PURPOSE: To evaluate periaortic hematoma (PH) near the level of the diaphragm at abdominal computed tomography (CT) as an indirect sign of acute traumatic aortic injury after blunt trauma in patients with mediastinal hematoma. MATERIALS AND METHODS: From 1998 to 2001, 97 patients with CT evidence of mediastinal hematoma after blunt thoracic trauma were retrospectively identified at two level 1 trauma centers. The presence or absence of PH near the level of the diaphragmatic crura was retrospectively established by a blinded reviewer at each institution. Aortic injury status was determined by reviewing angiographic, surgical, and clinical records. Sensitivity, specificity, positive and negative productive values, and positive and negative likelihood ratios were calculated. RESULTS: Among the 97 patients with mediastinal hematoma, 14 had both PH near the level of the diaphragm and aortic injury; six had aortic injuries without PH, five had PH near the level of the diaphragm without aortic injury, and 72 had no evidence of PH near the diaphragm and no aortic injury. Sensitivity for PH near the level of the diaphragm as a sign of aortic injury was 70%; specificity, 94%; positive predictive value, 74%; and negative predictive value, 92%. The positive likelihood ratio for the presence of aortic injury was 10.8, and the negative likelihood ratio was 0.3. CONCLUSION: PH near the level of the diaphragmatic crura is an insensitive but relatively specific sign for aortic injury after blunt trauma. The presence of this sign at abdominal CT should prompt imaging of the thoracic aorta to evaluate potential thoracic aortic injury.     

Subtle chest radiographic abnormalities in patients with traumatic aortic rupture

Objective: We reviewed admission chest radiographs of 107 patients with surgically proven traumatic aortic rupture (TAR) to determine if any of the studies appeared normal or nearly normal with regard to the aortomediastinal contour. Materials and Methods: The study group consisted of 107 patients with proven traumatic aortic rupture admitted to our institution from 1982 through 1992. Three radiologists reviewed these chest radiographs and by consensus excluded studies that had either a markedly abnormal aortomediastinal contour or were suboptimal technically. The remaining radiographs were evaluated to define any subtle abnormalities of the aortomediastinal contour that might indicate mediastinal hemorrhage. Results: There were no patients with TAR who had an entirely normal chest radiograph. Thirteen patients (12%) had subtly abnormal aortomediastinal contours, all of which had been prospectively interpreted as abnormal. Findings included an abnormal aortic contour or silhouette (13 patients), increased mediastinal/chest width ratio (6), a widened left paraspinal stripe (3), a widened right paratracheal stripe (2), and a widened right paraspinal line (1). Only 1 of the 13 patients had a mediastinal width greater than 8.0 cm. Conclusion: In this series no patient with proven TAR had a normal aortomediastinal contour, but abnormalities may be subtle and detection requires careful inspection of the aortic contour, and paraspinal and paratracheal soft tissues.     

Intrathoracic manifestations of metastatic testicular seminoma: a comparison of chest radiographic and CT findings

The chest radiographs and CT scans of 200 patients with pure testicular seminoma were reviewed. The radiographs showed evidence of intrathoracic metastatic disease in 25 patients (12.5%). Of these, 17 had an abnormal mediastinal contour, seven had pulmonary metastases, five had pleural effusions, and two had discrete pleural masses. CT showed evidence of intrathoracic metastatic disease in 30 patients (15%). This included mediastinal nodal enlargement in 21, pulmonary metastases in 12, pleural effusions in six, and pleural masses in two. CT not only showed disease in five patients with normal chest radiographs, but also showed additional sites of disease in four other patients with abnormal chest radiographs. The results suggest that mediastinal nodal enlargement is the most common intrathoracic manifestation of metastatic testicular seminoma. CT is more accurate than chest radiography in the detection of metastatic seminoma in the chest and defines the extent of metastatic disease more precisely.     

Spiral CT aortography: an efficient technique for the diagnosis of traumatic aortic injury

The objective of this study was to assess the efficiency of spiral CT (SCT) aortography for diagnosing acute aortic lesions in blunt thoracic trauma patients. Between October 1992 and June 1997, 487 SCT scans of the chest were performed on blunt thoracic trauma patients. To assess aortic injury, the following SCT criteria were considered: hemomediastinum, peri-aortic hematoma, irregular aspect of the aortic wall, aortic pseudodiverticulum, intimal flap and traumatic dissection. Aortic injury was diagnosed on 14 SCT examinations (2.9 %), five of the patients having had an additional digital aortography that confirmed the aortic trauma. Twelve subjects underwent surgical repair of the thoracic aorta, which in all but one case confirmed the aortic injury. Two patients died before surgery from severe brain lesions. The aortic blunt lesions were confirmed at autopsy. According to the follow-up of the other 473 patients, we are aware of no false-negative SCT examination. Our limited series shows a sensitivity of 100 % and specificity of 99.8 % of SCT aortography in the diagnosis of aortic injury. It is concluded that SCT aortagraphy is an accurate diagnostic method for the assessment of aortic injury in blunt thoracic trauma patients. Received 18 July 1997; Revision received 11 September 1997; Accepted 23 October 1997     

Urinary tract injury in patients with blunt chest trauma: The value of postaortographic abdominal radiographs

Patients who require thoracic aortography for blunt decelerating chest trauma often sustain injury to other organ systems due to the magnitude and mechanism of injury. Hospital records and radiographs of 117 consecutive, injured patients studied with thoracic aortography were evaluated to assess the accuracy, value, and limitations of postaortographic abdominal plain radiography for detection of major genitourinary injury. In summary, major urinary tract injury occurred with a frequency of 6%, enough to justify a rapid, low cost, noninvasive screening procedure. Postaortographic plain films of the abdomen were found to be an accurate (95%) screen for detection of major urinary tract injury. The sensitivity for detection of patients with renal injury was 100%. The ability to correctly predict patients who may be safely observed (no significant renal injury) was 100%. One limitation of this technique was the poor diagnostic quality found in 15% of the abdominal radiographs, most commonly caused by excessive superimposed bowel gas. Postaortographic pelvic radiographs were believed to be valuable for detection, but not exclusion, of bladder rupture.     

Endovascular Repair of Traumatic Rupture of the Thoracic Aorta: Single-Center Experience

Purpose Traumatic rupture of the thoracic aorta secondary to blunt chest trauma is a life-threatening emergency and a common cause of death, usually following violent collisions. The objective of this retrospective report was to evaluate the efficacy of endovascular treatment of thoracic aortic disruptions with a single commercially available stent-graft. Methods Nine men (mean age 29.5 years) were admitted to our institution between January 2003 and January 2006 due to blunt aortic trauma following violent motor vehicle collisions. Plain chest radiography, spiral computed tomography, aortography, and transesophageal echocardiography were used for diagnostic purposes in all cases. All patients were diagnosed with contained extramural thoracic aortic hematomas, secondary to aortic disruption. One patient was also diagnosed with a traumatic thoracic aortic dissection, secondary to blunt trauma. All subjects were poor surgical candidates, due to major injuries such as multiple bone fractures, abdominal hematomas, and pulmonary contusions. All repairs were performed using the EndoFit (LeMaitre Vascular) stent-graft. Results Complete exclusion of the traumatic aortic disruption and pseudoaneurysm was achieved and verified at intraoperative arteriography and on CT scans, within 10 days of the repair in all patients. In 1 case the deployment of a second cuff was necessary due to a secondary endoleak. In 2 cases the left subclavian artery was occluded to achieve adequate graft fixation. No procedure-related deaths have occurred and no cardiac or peripheral vascular complications were observed within the 12 months (range 8–16 months) follow-up. Conclusions This is the first time the EndoFit graft has been utilized in the treatment of thoracic aortic disruptions secondary to chest trauma. The repair of such pathologies is technically feasible and early follow-up results are promising.     

Unenhanced dynamic mediastinal computed tomography in the selection of patients requiring thoracic aortography for the detection of acute traumatic aortic injury

In our institution, the selection of patients who require thoracic aortography to evaluate for acute traumatic aortic injury (ATAI) is based upon an appropriate mechanism of injury and radiologic demonstration of a mediastinal hematoma. When plain chest or chest and/or mediastinal radiographs demonstrate a mediastinal hematoma, the patient undergoes thoracic aortography as promptly as is clinically feasible. If the plain film studies are negative for mediastinal hematoma, thoracic aortography is not performed because the patient is presumed not to have an ATAI. When the plain film studies are equivocal and the patient is stable, unenhanced computed tomography (CT) of the mediastinum is used to evaluate for a mediastinal hematoma. CT signs of a mediastinal hematoma include a soft tissue density, representing the hematoma admixed with mediastinal fat, which obscures or obliterates the normal aortic-mediastinal fat interface; hematoma admixed with fat of the right paratracheal stripe causing increased width and density of the stripe; and hematoma surrounding, and frequently displacing, the esophagus to the right of its normal position. Six of 36 patients (17%) with mediastinal hematoma demonstrated by unenhanced mediastinal CT had ATAI by thoracic aortography and confirmed surgically. The thoracic aortograms of the remaining 30 of 36 patients (83%) were negative. Sixty-three of 100 patients (63%) with equivocal plain chest or mediastinal radiographs had negative mediastinum by unenhanced CT. All 63 patients (100%) with normal mediastinal CT and who did not have thoracic aortography were discharged from the hospital 1–42 days (mean, 9.3 days) post-injury without clinical or radiographic signs of aortic rupture. Supported in part by the John S. Dunn Research Foundation.     

Traumatic injuries: imaging of thoracic injuries

Chest trauma is one of the most important causes of death, in particular in individuals under the age of 40 years. The mortality rate for chest trauma, often related to motor vehicle accidents, is approximately 15.5%; it increases dramatically to 77% with associated shock and head injury (Glasgow scores of 3-4). The accurate diagnosis of pathologies consequent to blunt chest trauma depends on a complete knowledge of the different clinical and radiological manifestations. The first diagnostic approach is classically based on chest X-ray often carried out on supine position at the hospital admission. A CT study must then be performed in all chest trauma patients in whom there is even the smallest diagnostic doubt on plain film. In particular, spiral CT (SCT) assumes a fundamental role in the demonstration of mediastinal hemorrhage and direct signs of aortic lesions. At present, SCT is routinely part of a diagnostic evaluation which also includes scans of the brain and the abdomen in polytraumatized patients. Magnetic resonance is the ideal method for visualizing diaphragmatic lesions. Furthermore, recent reports have demonstrated the high diagnostic value of MR in evaluating aortic injuries. The purpose of this article is to review the most common radiological patterns related to chest trauma.