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.     

Application of spiral computerized tomography in the study of traumatic lesions of the thoracic aorta

PURPOSE: Acute thoracic aortic injuries account for up to 10-20% of fatalities in high-speed deceleration road accidents and have an estimated immediate fatality rate of 80-90%. Untreated survivors to acute trauma (10-20%) have a dismal prognosis: 30% of them die within 6 hours, 40-50% die within 24 hours, and 90% within 4 months. We investigated the diagnostic accuracy of Helical Computed Tomography (Helical CT) in acute traumatic injuries of the thoracic aorta, and the role of this technique in the diagnostic management of trauma patients with a strong suspicion of aortic rupture. MATERIAL AND METHODS: We compared retrospectively the chest Helical CT findings of 256 trauma patients examined June 1995 through August 1999. All patients underwent a plain chest radiograph in supine recumbency when admitted to the Emergency Room. Chest Helical CT examinations were performed according to trauma score, to associated traumatic lesions and to plain chest radiographic findings. All the examinations were performed with no intravenous contrast agent administration and the pitch 2 technique. After a previous baseline study, contrast-enhanced scans were acquired with pitch 1 in 87 patients. All examinations were assessed for the presence of mediastinal hematoma, periaortic hematoma, traumatic pseudodiverticulum, irregular aortic wall or contour and intimal flap as signs of aortic rupture. RESULTS: Helical CT showed thoracic aortic lesions in 9 of 256 patients examined. In all the 9 cases we found a mediastinal hematoma and all of them had positive plain chest radiographic findings of mediastinal enlargement. Moreover, in 6 cases aortic knob blurring was also evident on plain chest film and in 5 cases depressed left mainstem bronchus and trachea deviation rightwards were observed. All aortic lesions were identified on axial scans and located at the isthmus of level. Aortic rupture was always depicted as pseudodiverticulum of the proximal descending tract and intimal flap. We also found periaortic hematoma in 6 cases and intramural hematoma in 1 case. There were no false positive results in our series: 7 patients with Helical CT diagnosis of aortic rupture were submitted to conventional aortography that confirmed both type and extension of the lesions as detected by Helical CT, and all findings were confirmed by gross inspection at surgery. No false negative results have been recorded so far: untreated aortic ruptures are fatal within 4 months in 90% of patients, or they may evolve into chronic pseudoaneurysm in about 5% of survivors. CONCLUSIONS: In our experience Helical CT had much higher diagnostic sensitivity and specificity than plain chest radiography. In agreement with larger published series, in our small one the diagnostic accuracy of Helical CT was 100% in the evaluation of traumatic aortic ruptures. Moreover, Helical CT is faster and less invasive than conventional aortography, which makes this diagnostic modality increasingly used and markedly improves the management of the serious trauma patient. The more widespread use of this diagnostic tool has permitted to standardize the technique and now Helical CT can be used not only as a screening modality for patients that undergo digital aortography, but also as a reliable diagnostic method for surgical planning.     

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.     

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.     

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.     

Classification of parenchymal injuries of the lung

Pulmonary contusion, implying interstitial and alveolar injury without significant laceration, has been accepted as the primary lung injury in nonpenetrating chest trauma. Computed tomographic (CT) findings were compared with those of chest radiography in 85 consecutive patients with chest trauma in which there was a pulmonary radiodensity consistent with pulmonary contusion or patients with a history of severe chest trauma with normal parenchyma despite rib fractures, hemothorax, pneumothorax, or widened mediastinum. CT was found to be more sensitive than radiography in that 151 abnormalities (excluding rib fractures) were demonstrated on radiographs versus 423 abnormalities on CT scans, and 99 lacerations were seen on CT scans versus five on radiographs. Pulmonary lacerations were classified into four types on the basis of CT findings and mechanism of injury: compression rupture, compression shear, rib penetration, and adhesion tears. In these cases, pulmonary laceration was shown to be an integral component of the mechanism of injury in pulmonary contusion, pulmonary hematoma, pulmonary cyst or pneumatocele, or cavitation in pulmonary contusion.     

Value of chest radiography in excluding traumatic aortic rupture

A retrospective review of chest radiographs from 205 patients with blunt chest trauma who also underwent aortography was performed. Forty-one of the 205 had aortographically proved aortic rupture. Discriminant analysis of 16 radiographic signs indicated that the most discriminating signs were loss of the aorticopulmonary window, abnormality of the aortic arch, rightward tracheal shift, and widening of the left paraspinal line without associated fracture. No single or combination of radiographic signs demonstrated sufficient sensitivity to indicate all cases of traumatic aortic rupture on plain chest radiographs without the performance of a large number of aortographically negative studies. The bedside anteroposterior "erect" view of the chest proved far more valuable than the supine view in detecting true-negative studies. Despite significant reader variability in the interpretation of the various radiographic signs, in general the analysis confirmed the role of chest radiography in this clinical situation, but suggests that its most beneficial use is in excluding the diagnosis and eliminating unwarranted aortography rather than in predicting aortic rupture.     

Chest wall, lung, and pleural space trauma

Chest radiographs frequently underestimate the severity and extent of chest trauma and, in some cases, fail to detect the presence of injury. CT is more sensitive than chest radiography in the detection of pulmonary, pleural, and osseous abnormalities in the patient who has chest trauma. With the advent of multidetector CT (MDCT), high-quality multiplanar reformations are obtained easily and add to the diagnostic capabilities of MDCT. This article reviews the radiographic and CT findings of chest wall, pleural, and pulmonary injuries that are seen in the patient who has experienced blunt thoracic trauma.     

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.     

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.     

Acute posttraumatic rupture of the thoracic aorta: The role of angiography in a 7-year review

Between 1983 and 1989, 15 patients with acute rupture of the thoracic aorta by blunt trauma were seen. Superior mediastinal widening and obscuration of the aortic arch were the most important findings on chest radiograph. Computed tomography examinations in 7 patients showed mediastinal hematomas but did not reveal aortic lesions. Definitive diagnosis of traumatic aortic rupture was established by aortography in all 15 patients. Intraarterial digital substraction angiography proved to be as accurate as conventional film aortography and saved time.     

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.     

Value of imaging procedures in the diagnosis and therapy of severe thoracic injuries

Plain chest radiographs allow the diagnosis of most intrathoracic injuries. However, they are only momentary pictures and give no information on the respiratory function. A tension pneumothorax, rib fractures and subcutaneous emphysema should be diagnosed clinically before radiographs are taken. Computed tomography is helpful in evaluation of intrapulmonary lesions, hemothorax, rupture of the diaphragm and dislocation of the heart. Further diagnostic tools include aortography in suspected aortic rupture, sonography in cardiac injuries and hemopericardium, bronchoscopy in suspected bronchial or tracheal rupture, ECG and enzyme determinations in cardiac contusion, and eventually pneumoperitoneum in suspected rupture of the diaphragm.     

家兔肺挫伤早期影像学的变化及其意义

目的探讨单光子发射计算机断层显像(SPECr)、胸部CT以及x线平片对家兔肺挫伤的早期诊断价值。方法建立兔单侧胸部撞击伤动物模型,采用SPECT、胸部CT以及x线平片对兔肺挫伤进行早期诊断,并与病理解剖结果进行对照观察。结果在伤后1、6、24小时,x线诊断肺挫伤的敏感性分别为33．33％(3／9)、55．56％(5／9)、75．00％(6／8),有2只动物未检出肺挫伤病变。在伤后1小时,CT显示双肺均有挫伤100％(2／2),结合动物病理观察,CT与实际伤情非常吻合,而x线低估了肺挫伤的病变范围。结论胸部CT在诊断胸部创伤获得治疗相关信息方面明显优于x线平片。因此,对于严重胸部创伤以及多发伤,急诊检查应采甩CT扫描,以尽快明确诊断。     

Traumatic injuries: imaging of peripheral musculoskeletal injuries

The current dominant role of conventional radiography must be reassessed at increasingly shorter intervals in view of the continuing emergence of new imaging modalities that are available to diagnose peripheral musculoskeletal injuries. In comparison with conventional radiography, digital radiographic techniques offer advantages for optimization of image quality and dose, such as a wider dynamic range and post-processing of images. Currently, digital luminescence radiography (storage phosphor radiography) is the most commonly used digital method for obtaining radiographs, using the established positioning projections and routines of the film-screen technique. A new process, radiography with flat-panel amorphous silicon detectors, is still under development. Computed tomography is a valuable tool for diagnosing injuries of the peripheral musculoskeletal system, especially when three-dimensional data sets are acquired; these allow reformating images in all planes desired (2D technique) or in a volumetric format (3D technique). Established indications for CT in the peripheral skeleton are hip fractures, wrist injuries and calcaneal fractures; however, CT may be used as a supplement to radiography in every region of the body. Sonography is beginning to play an increasingly important role in trauma. Muscle and tendon injuries are the most common indications, but worthwhile information can be gained of the shoulder, elbow, hip, and knee joints, supplementing conventional or digital radiography. Magnetic resonance imaging effectively visualizes traumatic changes of the skeleton and the peripheral soft tissues. It is the method of choice to detect occult fractures. It can be used to diagnose muscle and tendon injuries. Joint injuries, especially in the knee and the shoulder joint, are common indications for MRI in the posttraumatic setting.     

False-positive aortography following blunt chest trauma: Case report

We describe a patient in whom thoracic aortography performed following blunt chest trauma revealed what appeared to be a traumatic tear of the proximal descending aorta. As the patient initially refused surgery, aortography was repeated 18 days later, confirming these findings. At thoracic aortotomy the aorta appeared normal; there was no hematoma or tear. We believe this to be the first reported case of false-positive aortography following blunt chest trauma (see Note added in proof).     

Is there need for thoracic spine radiographs following a negative chest CT in trauma patients?

The purpose of this study was to assess the need for conventional radiographs of the thoracic spine for routine clearance of trauma patients in whom chest CT has revealed no spinal trauma. The study was in the form of a retrospective review of trauma patients over the previous five years who underwent conventional radiographs of the thoracic spine following a chest CT that revealed no spinal trauma. Two hundred thirty-five trauma patients were found to have undergone conventional thoracic spine series following a chest CT that showed no spinal trauma. In 234 of the cases, the thoracic spine series was also negative. In one case, the thoracic spine series revealed mild anterior compression of the T7 vertebral body. This injury was stable and required no specific intervention. CT of the chest is an adequate evaluation of the thoracic spine in trauma patients who require routine thoracic spine clearance, making subsequent conventional radiographs of the thoracic spine unnecessary. Electronic Publication     

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.     

Computed tomography in the diagnosis of traumatic rupture of the thoracic aorta

Over a 26-month period, 25 patients admitted to the Trauma Unit at UCSD Medical Center following blunt trauma were investigated for suspected traumatic rupture of the thoracic aorta by computed tomography (CT) of the chest. A retrospective review of these patients was performed. Twenty-one (84%) also had CT of other body areas, most commonly the head or abdomen. Nine of the 25 patients subsequently had aortography; in 15 patients the CT findings were felt at the time to exclude rupture, and one patient was not investigated further because of severe head injuries. In general, if CT failed to show a mediastinal haematoma, aortography was not performed. However, five patients with CT evidence of a haematoma, including two with vertebral fractures, were not investigated by aortography. Two of the 25 patients (8%) had angiographically proven aortic ruptures; in both CT had shown not only a haematoma but also an abnormal outline of the aorta on contrast-enhanced scans. The haematoma was large in one patient and small in the other. Although 10 of the 25 patients had unenhanced scans, no case of aortic rupture is known to have been missed. During the same study period, 47 patients were investigated for suspected aortic rupture solely by aortography. Four patients (8% of this group) had aortic rupture, and two had subclavian or innominate artery ruptures. Only a minority (approximately one-quarter) also had CT of the head or abdomen. The role of CT in the diagnosis of traumatic rupture of the aorta is critically assessed in the light of our experience and a review of the literature.     

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.