Multidetector Computed Tomography of Nonosseous Thoracic Trauma Kristopher W. Cummings, MD, Cylen Javidan-Nejad, MD, and Sanjeev Bhalla, MD

Introduction

Technique

T

Unless contraindicated based on allergy or renal failure, MDCT in the setting of trauma should be performed with the use of intravenous contrast. The potential benefit of visualizing direct signs of vascular injury or an area of blush (indicative of active extravasation or pseudoaneurysm formation) far outweighs any theoretical risks. MDCT of the thorax should be performed using a technique that allows high-quality multiplanar reconstructions (MPRs) and provides source images that allow volume-rendered images as well. At our institution, we scan using a pitch of 1 with 3-mm reconstructions at 2-mm intervals. The 33% overlap allows for high-quality MPRs and yet, 3-mm images do not result in an inordinate number of images. The balance between a manageable image burden and thin sections has become harder in the MDCT era. We only scan once in the setting of trauma. We have not found precontrast images of any help.

rauma to the thorax is commonly encountered in the emergency department (ED). In some registries, thoracic injury ranks third after head and extremity injury in the setting of blunt trauma.1 When critical, it may direct the patient's immediate course (as in the setting of acute aortic injury or blunt cardiac injury). Even when not life threatening, the presence of thoracic injury may affect management. A pneumothorax, for example, may require emergent thoracostomy tube placement before surgical correction of a pelvic fracture. Chest radiography remains a frequently used screening tool owing to its low cost and portability. Multidetector computed tomography (MDCT) continues to make inroads in the evaluation of radiographic abnormalities and in the exclusion of significant injury in the setting of an appropriate mechanism (high-speed collision or high fall) in the posttrauma patient. The increase in the use of computed tomography (CT) has been driven by its ready availability at all hours, its ability to detect subtle disease missed by radiography, and its ability to change management in almost one-fifth of trauma patients.2,3 Most often, CT is performed to evaluate abnormal findings on chest radiograph, but occasionally MDCT may be used as a firstline tool. The goal of this article is to highlight the features of blunt and penetrating thoracic traumatic conditions, including aortic and cardiac injury, on MDCT images. Occasionally, these conditions may be encountered in isolation, but more often, they are seen in conjunction with other injuries (both intrathoracic and extrathoracic).

Cardiothoracic Imaging Section, Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO. Address reprint requests to Sanjeev Bhalla, MD, Cardiothoracic Imaging Section, Mallinckrodt Institute of Radiology, Washington University in St. Louis, 510 South Kingshighway, St. Louis, MO 63110. E-mail: [email protected]

134

0037-198X/14/$-see front matter & 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.ro.2014.01.002

Abnormal Gas Collections In the setting of trauma, abnormal gas may be seen in the pleural space (pneumothorax), mediastinum (pneumomediastinum), or pericardium (pneumopericardium). Recognition of the type of gas is important as each may have a different etiology and different significance.

Pneumothorax Pneumothorax is fairly common and may be seen in 20%-40% of blunt trauma patients presenting to the ED.4,5 Despite its high frequency and the high awareness of its potential, up to 50% of pneumothoraces may be missed on portable radiography.5,6 These occult pneumothoraces are rarely symptomatic but they may require thoracostomy if mechanical ventilation is contemplated. When positive end-expiratory pressure is used, even a small pneumothorax can become quite large. The key on CT is to see a black space surrounding the lung. Usually, the gas moves to a nondependent location. An occasional web may be seen, but webs should not be the dominant feature. Some

MDCT of nonosseous thoracic trauma

135

Figure 1 Tension pneumothorax. A 27-year-old woman ejected from a motor vehicle after collision at high speed was found to have a large left anterior pneumothorax, which displaces the heart rightward (A) and depresses the left hemidiaphragm (B), indicative of tension effect.

authors have tried to use measurements of the thickness or volume of the pneumothorax to determine which patients requires treatment.1 We have not found these to be accurate predictors. Instead, we rely on symptoms and the predicted hospital course to help decide which pneumothoraces will warrant thoracostomy placement. A small pneumothorax, for example, may be drained if mechanical ventilation is required, whereas a moderate-sized pneumothorax may be followed up in another patient with no other injuries. When a pneumothorax is seen, care should be taken to look for any potential concomitant rib fracture or any tension effect on the heart and mediastinum (Fig. 1). As radiography is not always performed prior, CT may be the first modality to suggest the presence of a tension pneumothorax. If a thoracostomy tube is on suction and within the pleural space and a pneumothorax is still present, one should carefully look for a bronchial or tracheal injury as either may explain an air leak in the trauma setting. Before diagnosing a pneumothorax, one should also verify that an excessively sharp kernel was not used. If a bone algorithm is used to visualize the lungs, a relative black line to the ribs is created by the sharpening. In certain cases, this artifact can simulate a pneumothorax.

neck and subcutaneous tissues. Less commonly, the gas can dissect laterally into the subpleural space. At first glance, this lateral extension may simulate a pneumothorax, but the presence of multiple webs should help in avoiding the confusion. Some cases of pneumomediastinum may be from either esophageal or tracheal injuries. Because of this association, care must be taken to look carefully at the airway and esophagus. Additional findings discussed later may help in revealing these underlying causes.

Pneumomediastinum Most cases of pneumomediastinum in the setting of blunt trauma arise from the Macklin effect, whereby an alveolar rupture results in gas dissecting along the bronchovascular sheath into the mediastinum.7,8 The belief is that this phenomenon comes from either barotrauma or increased pressure against a closed glottis. The pressure from the ruptured alveolus or alveoli is not sufficient to result in a pneumothorax but can result in a pneumomediastinum. Unlike a pneumothorax, the gas within a pneumomediastinum represents gas dissecting in a false space (Fig. 2). The net effect is the visualization of multiple webs. Occasionally, the pneumomediastinum can dissect into the soft tissues of the

Figure 2 Pneumomediastinum. A 63-year-old woman after a fall down a flight of stairs presented with moderate pneumomediastinum without esophageal or tracheal injury. The patient had a tiny right anterior pneumothorax. The extensive webs typical of pneumomediastinum and the absence of such webs in the right pneumothorax can be noted. A component of the subcutaneous gas can be seen dissecting in the intercostal muscles and fascia. This lateral extension of pneumomediastinum also has webs, which allows distinction from the pneumothorax.

K.W. Cummings et al

136

considered. In some centers, a fast rate of drainage (eg, 100 mL/h for 5 hours) may also result in surgical exploration.

Diaphragmatic Injury

Figure 3 Pneumopericardium. A 30-year-old man after a motor vehicle collision with extensive right lung contusion and lacerations was found to have a small pneumopericardium on performing CT. The absence of webs, which are typical of pneumomediastinum and not pneumomediastinum, can be noted.

Pneumopericardium Like pneumothorax, a pneumopericardium represents gas in a true potential space. In this case, the gas resides in the cavity surrounding the heart (Fig. 3). The gas collection should be free of webs and should move to the least dependent portion of the pericardium. Pneumopericardium is unusual after blunt trauma. When it is encountered, one must look for a pericardial defect (either congenital or acquired). Occasionally, the defect can act like a 1-way valve or the gas can exert mass effect on the heart. The resulting increased pressure can result in a tamponadelike effect. If not emergently drained, this tension pneumopericardium can be lethal. In the setting of a penetrating trauma, a pneumopericardium may be indicative of underlying cardiac injury. CT is not a reliable way to exclude laceration of the heart as the right ventricle free wall is only 23 mm in size.9 In many centers, the presence of pneumopericardium after a gunshot or knife injury is enough to warrant surgical exploration.

Diaphragmatic injuries in blunt trauma are fairly uncommon (o5% of blunt trauma patients) and range from minor abnormalities to blatantly obvious ones.11 The belief is that a sudden increase in intra-abdominal pressure creates a tear at a site of embryologic fusion or diaphragmatic attachment.11,12 The key to diagnosis is the realization that the expected diaphragmatic contour is abnormal. In other words, the stomach or liver appear to be craniad than expected on either radiographs or CT images. Although radiography may suggest diaphragmatic injury by displacement of the stomach bubble or an abnormal course of the nasogastric tube, CT is almost always used to confirm the injury (Fig. 5). As the diaphragm is a thin structure that travels in a transaxial plane, it can be very hard to see on transverse CT images. Coronal and sagittal multiplanar images can be quite helpful in the evaluation of an injured diaphragm. Left hemidiaphragm injuries are more commonly seen than right hemidiaphragm injuries in the ED. Some have postulated that this may be from a protective effect of the liver.1 Our experience is that right-sided injury is probably more common than previously thought and the liver may be protective, but it also makes right-sided injuries harder to detect. When an organ herniates through the injury, the diagnosis is much easier to make. Named signs include the collar sign, a waistlike narrowing of the hollow viscus at the defect, and the dependent viscera sign, in which the herniated organ falls against the posterior chest wall.13,14 Both are more common on the left. In a right-sided defect, some have referred a herniated portion of the liver as the hump sign or cottage bread sign.14 Other

Hemothorax In the setting of both penetrating and blunt trauma, a pleural effusion should be assumed to be blood or a hemothorax until proven otherwise. Unless the hemothorax is hyperacute, it will tend to measure 3070 HU.1,10 Care should be taken to look for areas of high attenuation (close to blood pool) that could represent active extravasation or the formation of a pseudoaneurysm (Fig. 4). Either of them may prompt a need for percutaneous treatment by interventional radiology. Almost all hemothoraces result in thoracostomy tube placement so as to prevent development of a constrictive fibrothorax. The drainage may also be used to guide management. If the initial drainage exceeds 1 L, the hemothorax may be considered massive and surgical exploration may be

Figure 4 Hemothorax with active arterial bleeding. A 50-year-old man who sustained a stab wound to the left chest was found to have a large, high-attenuation left pleural effusion in keeping with a hemothorax. In addition, areas of contrast blush along the posterior left thoracic cavity, equal in density to arterial contrast (black arrow), were noted because of active arterial bleeding from an injured intercostal artery.

MDCT of nonosseous thoracic trauma

137

Figure 5 Traumatic rupture of the left hemidiaphragm. A 26-year-old man presented to the emergency room complaining of left chest pain after a rollover all-terrain vehicle accident. Axial CT image (A) demonstrates the gas and fluid-filled stomach in the left thorax, at the level of the heart, directly abutting the posterior thoracic wall without an intervening atelectatic lung (dependent viscera sign). Coronal CT reformat image (B) demonstrates herniation of the stomach into the left thorax through a large diaphragmatic defect (white arrow).

findings that have been reported in diaphragm injury include absence of visualization of the diaphragm, retraction and thickening of the torn diaphragm, and blood in the pleura and peritoneum simultaneously, without associated injuries in both spaces.14 Despite the observation of more than 19 named signs in diaphragmatic injury, CT sensitivity has been reported to be as low as 70%.15 Most authors agree that in the MDCT era and with the routine use of coronal and sagittal reformations, CT is more robust than what has been reported.1,14,15

Parenchymal Injuries Pulmonary Contusion Pulmonary contusion represents a fairly common injury pattern whereby blood fills the alveolar spaces after trauma but no significant alveolar injury is encountered (Fig. 6). The net effect is that a contusion peaks within the first 6 hours after a traumatic event and begins to start clearing by 24 hours.16,17 By a week, a contusion has usually completely cleared. The

Figure 6 Contusions and lacerations. A 30-year-old patient with extensive right pulmonary contusions and laceration. Note that on follow-up examination (B), which was performed 8 days later, the contusions have resolved but the laceration remains.

K.W. Cummings et al

138

mediastinal widening is most often because of the supine nature of the portable trauma chest radiograph and mediastinal fat. Although many patients can easily be cleared by an upright radiograph, CT is often performed as the next step. Assuming the widening is related to the trauma, most abnormalities result from vascular, esophageal, or tracheal injury.

Aortic and Great Vessel Injury

Figure 7 Pulmonary laceration. A 19-year-old man after a gunshot injury to the left thorax was found to have a large area of contusion in the left lower lobe with a focal pulmonary laceration containing a small amount of layering blood on performing CT. The bullet fragments adjacent to a fractured left thoracic transverse process can be noted.

timing of a contusion can be important as it allows a distinction from other entities. Persistent airspace opacity may be indicative of an underlying laceration. Airspace disease that begins after a few days is likely to be reflective of pneumonia, alveolar damage, fat emboli, or acute pulmonary emboli. Contusions usually present adjacent to the site of injury in blunt trauma and may mimic pneumonia. Occasionally, the contusion may be on the opposite side of the trauma (contrecoup pattern). Rarely, contusions may present with a ground-glass nodular pattern. These nodules mimic centrilobular nodules and tend to spare the pleura.1 They can be distinguished from aspiration by their nondependent location.

Pulmonary Laceration Unlike a contusion, a laceration represents disruption of the lung parenchyma. The elastic recoil of the lung results in a space that can get filled with either gas (pneumatocele) or blood (hematocele or hematoma). More commonly, the laceration is filled with both gas and blood (hematopneumatocele or, simply, a laceration) (Fig. 7). Often a laceration is surrounded by a contusion and evades detection on radiography. As the contusion begins to clear, the laceration becomes more apparent. Lacerations may persist for long periods after trauma as pneumatoceles do. Lacerations may be single or multiple. Some authors have advocated classifying them by CT based on location and mechanism. We have not found a grading system to be helpful. The lacerations are usually managed symptomatically. Their significance is that care should be taken to look for any areas of high attenuation within the laceration that might indicate active bleeding.

Mediastinal Injuries Abnormal mediastinal contour detected on radiography is a frequent indication for CT in the setting of trauma. The

Aortic and great vessel injuries represent 2 of the most dreaded consequences of thoracic trauma even though both are fairly rarely encountered in the ED. Because of its potential lethality (up to 15% of deaths after motor vehicle collisions may be secondary to aortic and great vessel injury), one must be aware of the findings on CT.18 However, in the MDCT era, we have also learned that not all vascular injuries are lethal. In fact, some may not even require treatment beyond β-blockade.19 The challenge is to know which injuries require emergent repair. The key to understanding the CT features relies on understanding the concept of indirect and direct signs of a vascular injury.20 The former refers to a hematoma that effaces the fat plane of a suspected injured vessel. When this finding is encountered, one must look carefully for a direct sign. The indirect sign would have more than 95% sensitivity for detecting injury but less than a 10% specificity.19,20 When no direct sign is encountered, the indirect sign in isolation usually results in clinical observation or a second imaging test (usually repeat CT a few hours later or angiography). Patients are almost never sent for treatment on the presence of an indirect sign alone. Direct signs of vascular injury include the visualization of a flap, eccentric thrombus, intimal irregularity, intramural hematoma, vascular contour abnormality, abrupt change of vascular caliber, or abrupt cut-off of the vessel 20-23 (Fig. 8). Although extravasation of contrast is the most easily understood of the direct signs, it is rarely encountered. The direct signs are indicative of the actual injury and sometimes are more easily seen on sagittal oblique reconstructions. For many years it was said that a direct sign of injury should lead directly to treatment. Recently, this treatment has been in the form of endoluminal repair.19 In a group of patients, the added use of MDCT has helped detect the direct sign of injury of minimal intimal irregularity without an intramural hematoma or mediastinal hematoma, dubbed minimal aortic injury24 (Fig. 9). Preliminary experience at many centers seems to imply that these patients may not require surgery.19,24 At our center, repeat CTs are performed until documented resolution or progression. If the latter is encountered, the patients are referred for treatment. Most aortic injuries in blunt trauma that survive to imaging are found in the aortic isthmus near the attachment of the ligamentum arteriosum.18 Likely, this is related to differential deceleration related to the tethering of the aorta at this level. The net effect is that on radiographs and CT images, most hematomas related to aortic injury (from either aortic blood or adjacent venous injury) appear largest in the left paratracheal region near the aortic isthmus. The resultant mass effect displaces midline structures rightward

MDCT of nonosseous thoracic trauma

139

Figure 8 Acute traumatic aortic injury. A 20-year-old man who was an unrestrained driver in a high-speed motor vehicle collision complained of severe chest pain. CT image demonstrates a focal flap and contour irregularity (A) in the proximal descending thoracic aorta with surrounding hematoma in the mediastinal fat. Oblique sagittal CT reconstruction image (B) demonstrates the size and location of the focal acute aortic injury just distal to the takeoff of the left subclavian artery.

and the left main bronchus inferiorly. Most ascending aortic injuries are lethal but few survive to be imaged. The main hassle for the ED radiologist is the frequency of ascending aortic artifacts on CT (usually related to cardiac pulsation), which far outnumbers that of true injuries. Usually, awareness of this artifact is sufficient to overlook it. Occasionally, repeat imaging with electrocardiogram gating or with ultra–

high-pitch mode may be performed in more difficult cases. In our practice, the need for gating is low enough that we reserve it as a problem-solving tool. Technical limitations and the trauma patient's frequent tachycardia prevent more widespread use.1 Great vessel injury is less commonly seen than aortic injury is.25 As with aortic injuries, direct and indirect signs

Figure 9 Minimal traumatic aortic injury. A 34-year-old man thrown from a dirt bike after collision with an all-terrain vehicle. In addition to splenic and renal lacerations and complex left femur fracture, the patient was found to have focal intraluminal thrombus arising from the anterior wall of the middescending thoracic aorta without evidence of active contrast extravasation or surrounding hematoma.

Figure 10 Esophageal injury. A 72-year-old woman with ankylosing spondylitis presented after a motor vehicle collision. Adjacent to the site of a thoracic spine transection, bubbles of gas can be seen indicative of an esophageal injury. This location is characteristic of this rare entity.

K.W. Cummings et al

140

visualization of an ectopic location of the endotracheal balloon outside the airway. Bronchial injuries are more commonly seen than tracheal injuries and usually only involve a portion of the wall. When a complete transection is present, the ipsilateral lung distal to the injury may collapse away from the mediastinum. This finding is known as the fallen lung sign. When the transection is incomplete, the injury is more easily overlooked. A potential outcome is scarring and stenosis at the injury site.

Cardiac and Pericardial Injuries Hemopericardium

Figure 11 Tracheal injury. A 51-year-old woman who was an unrestrained driver in a high-speed motor vehicle collision had findings of extensive subcutaneous crepitus over her chest and abdomen on physical examination. CT image reveals focal discontinuity along the right posterolateral aspect of the proximal thoracic trachea (white arrow) and extensive subcutaneous gas and pneumomediastinum.

can be used to diagnose and guide management. The key is to realize that any hematoma associated with great vessel injury is located more cranially in the mediastinum. As the innominate artery is the most frequently injured, the mediastinal hematoma may be mostly in the right paratracheal region and displace the midline structures leftward. As with aortic injuries, great vessel injuries may be more easily appreciated on volume-rendered reconstructions and MPRs.

As with hemothorax, the presence of a moderate-sized pericardial effusion after trauma is suspicious for hemopericardium. If the attenuation is between 30 and 70 HU, the diagnosis is more certain. When encountered, one must look for potential cardiac injury, and careful inspection of the myocardium should be performed.1 Moreover, care should be taken to look for any bright blushes that may be indicative of active extravasation from the heart or great vessels. Most of the time a source for the hemopericardium cannot be readily determined. When the hemopericardium is large, the fluid may exert mass effect on the heart and result in tamponade. CT features of tamponade include flattening of the wall of the right ventricle or right atrium, distension of the vena cavae, or increased flow in collateral pathways. Usually the presence of a hemopericardium would prompt a follow-

Esophageal Injuries Like the aorta, the esophagus in blunt trauma is prone to injury at the site at which it goes from being mobile to fixed. In the case of the esophagus, this region is at the cervicothoracic junction (Fig. 10). Although extremely rare, these esophageal injuries tend to exist with lower cervical or upper thoracic fractures.26 CT findings that suggest esophageal injury include pneumomediastinum, air-fluid levels in the mediastinum, and airspace disease suggestive of aspiration.27 If only pneumomediastinum is present, then esophageal injury is highly unlikely. The next step might be to obtain a water-soluble esophagram if the clinical suspicion remains high.

Tracheal and Bronchial Injuries Airway injuries are slightly more common than esophageal injuries. Many patients die in the field of these injuries because of the inability to adequately ventilate.28,29 They may be suspected when there is a large pneumomediastinum or a large pneumothorax despite the presence of an adequately placed chest tube (Fig. 11). Diagnosis can be made on CT with direct visualization of the defect or

Figure 12 Cardiac contusion. A 40-year-old man presented with ventricular fibrillation arrest after running into a basketball pole, striking his anterior chest, at high speed while playing basketball. Contrast-enhanced CT image demonstrates a large area of hypoattenuation at the left ventricular apex. Although the patient had elevated troponin levels, he had no evidence of coronary atherosclerosis on cardiac catheterization and was diagnosed with a traumatic cardiac contusion.

MDCT of nonosseous thoracic trauma

141

Figure 13 Penetrating trauma. Diaphragmatic injury after a stab wound. A 22-year-old woman suffered left upper quadrant stabbing. The pellet in (A) represents the knife-entry wound. When the tract is followed more cranially, a defect can be seen in the left hemidiaphragm (arrow in B). Such a small defect could easily be missed if the tract had not been followed.

up echocardiogram to see if any early signs of tamponade are present and to assess the condition of the underlying myocardium.

detection of coronary injury usually requires a gated, dedicated coronary artery protocol.

Penetrating Trauma Cardiac Injury For many years, cardiac injury (formerly, contusion) was thought to be outside the realm of chest CT. The advent of MDCT with routine, rapid thin-section imaging has changed all of that. With 3-mm reconstructions and isotropic data sets allowing for submillimeter reconstructions when needed, the heart should be a part of any trauma CT search pattern. At our institution, we do not perform CT scans with the goal of finding cardiac injury, but the newer techniques allow for its visualization when present. Cardiac injuries range from simple contusions that may be occult on CT to frank cardiac rupture.30-32 The CT features range from slight decrease in attenuation in the myocardium to visualization of a defect in the myocardium and extravasation of contrast material into the pericardial space (Fig. 12). Because of its anterior location, the right ventricle is the most commonly injured cardiac chamber.1,31,32 The thin wall (23 mm) makes it hard to assess for injury unless there is a focal defect present. As a result, any electrocardiogram or enzyme abnormality would prompt echocardiography. The presence of wall motion abnormalities in the absence of any known ischemia is considered cardiac injury. Occasionally, trauma results in a septal defect (usually interventricular). These may be seen on CT when large. They are much better seen on echocardiography or magnetic resonance. Trauma may also result in injury to the coronary arteries. This pattern of injury is usually appreciated when ischemic or infarct changes are seen in the myocardium. CT

Penetrating trauma from a knife or bullet results in the same spectrum of injury as seen with blunt trauma. Care must be taken to reconstruct the path of the knife or projectile. If the path crosses the trachea, esophagus, diaphragm, or heart, these organs likely have been injured. Traditional findings of pneumomediastinum may be absent in penetrating esophageal or tracheal injury.9 Penetrating injury of the diaphragm may be similarly occult. When the path of the projectile crosses the diaphragm, it has also probably been injured (Fig. 13). The findings described earlier (including the fallen viscera sign and collar sign) are more often absent than present. As a cardiac laceration may be similarly occult, hemopericardium, in the setting of penetrating trauma, may be sufficient to warrant surgical exploration for cardiac injury. In addition to using the projectile path to predict injured organs, the radiologist should closely inspect the path for any signs of active bleeding. Any blush should be reported as it may represent an active bleed or pseudoaneurysm and may prompt percutaneous embolization.

Conclusion Advances in CT have resulted in its widespread use in the setting of both blunt and penetrating trauma. Radiologists should be familiar with the CT findings of thoracic trauma as it is both common and potentially lethal. By understanding these findings, they can help the trauma team make sure that the patient is triaged appropriately.

142

References 1. Kaewlai R, Avery LL, Asrani AV, et al: Multidetector CT of blunt thoracic trauma. Radiographics 28:1555-1570, 2008 2. Exadaktylos AK, Sclabas G, Schmid SW, et al: Do we really need routine computed tomographic scanning in the primary evaluation of blunt chest trauma in patients with “normal” chest radiograph? J Trauma 51:1173-1176, 2001 3. Omert L, Yeaney WW, Protetch J: Efficacy of thoracic computerized tomography in blunt chest trauma. Am Surg 67:660-664, 2001 4. Mayberry JC: Imaging in thoracic trauma: The trauma surgeon's perspective. J Thorac Imaging 15:76-86, 2000 5. Miller LA: Chest wall, lung, and pleural space trauma. Radiol Clin North Am 44:213-224, 2006 6. De Moya MA, Seaver C, Spaniolas K, et al: Occult pneumothorax in trauma patients: Development of an objective scoring system. J Trauma 63:13-17, 2007 7. Macklin CC: Transport of air along sheaths of pulmonic blood vessels from alveoli to mediastinum: Clinical implications. Arch Intern Med 64:913-926, 1939 8. Wintermark M, Schnyder P: The Macklin effect: A frequent etiology for pneumomediastinum in severe blunt chest trauma. Chest 120:543-547, 2001 9. Shanmuganathan K, Matsumoto J: Imaging of penetrating chest traumaRadiol Clin North Am 44(2):225-238, 2006 10. Livingston DH, Haurer CJ: Trauma to the chest wall and lung. In: Moore EE, Feliciano DV, Mattox KL (eds): Trauma, 5th ed. Philadelphia, PA, McGraw-Hill, 507-537, 2004 11. Sliker CW: Imaging of diaphragmatic injuries. Radiol Clin North Am 44:199-211, 2006 12. Mirvis SE, Shanmuganathan K: Imaging hemidiaphragmatic injury. Eur Radiol 17:1411-1421, 2007 13. Bergin D, Ennis R, Keogh C, et al: The “dependent viscera” sign in CT diagnosis of blunt traumatic diaphragmatic rupture. Am J Roentgenol 177:1137-1140, 2001 14. Desir A, Ghaye B: CT of blunt diaphragmatic rupture. Radiographics 32 (2):477-498, 2012 15. Larici AR, Gotway MB, Litt HI, et al: Helical CT with sagittal and coronal reconstructions: Accuracy for detection of diaphragmatic injury. Am J Roentgenol 179:451-457, 2002 16. Wagner RB, Crawford Jr WO, Schimpf PP: Classification of parenchymal injuries of the lung. Radiology 167:77-82, 1988

K.W. Cummings et al 17. Cohn SM: Pulmonary contusion: Review of the clinical entity. J Trauma 42:973-979, 1997 18. Pretre R, Chilcott M: Blunt trauma to the heart and great vessels. N Engl J Med 336:626-632, 1997 19. Lee WA, Matsumura JS, Mitchell RS, et al: Endovascular repair of traumatic thoracic aortic injury: Clinical practice guidelines of the Society for Vascular Surgery. J Vasc Surg 53(1):187-192, 2011 20. Mirvis SE, Shanmuganathan K: Diagnosis of blunt traumatic aortic injury 2007: Still a nemesis. Eur J Radiol 64:27-40, 2007 21. Kuhlman JE, Pozniak MA, Collins J, et al: Radiographic and CT findings of blunt chest trauma: Aortic injuries and looking beyond them. Radiographics 18(5):1085-1106, 1998 22. Patel NH, Stephens Jr KE, Mirvis SE, et al: Imaging of acute thoracic aortic injury due to blunt trauma: A review. Radiology 209(2):335-348, 1998 23. Fishman JE: Imaging of blunt aortic and great vessel trauma. J Thorac Imaging 15(2):97-103, 2000 24. Kidane B, Abramowitz D, Harris JR, et al: Natural history of minimal aortic injury following blunt thoracic aortic trauma. Can J Surg 55(6):377-381, 2012 25. Gavant ML, Menke PG, Fabian T, et al: Blunt traumatic aortic rupture: Detection with helical CT of the chest. Radiology 197 (1):125-133, 1995 26. Young CA, Menias CO, Bhalla S, et al: CT features of esophageal emergencies. Radiographics 28(6):1541-1553, 2008 27. Ho AS, Ahmed A, Huang JS, et al: Multidetector computed tomography of spontaneous versus secondary pneumomediastinum in 89 patients: Can multidetector computed tomography be used to reliably distinguish between the 2 entities? J Thorac Imaging 27(2):85-92, 2012 28. Chen JD, Shanmuganathan K, Mirvis SE, et al: Using CT to diagnose tracheal rupture. Am J Roentgenol 176:1273-1280, 2001 29. Scaglione M, Romano S, Pinto A, et al: Acute tracheobronchial injuries: Impact of imaging on diagnosis and management implications. Eur J Radiol 59:336-343, 2006 30. Fulda G, Brathwaite CE, Rodriguez A, et al: Blunt traumatic rupture of the heart and pericardium: A ten-year experience (1979–1989). J Trauma 31:167-173, 1991 31. Clancy K, Velopulos C, Bilaniuk JW, et al: Screening for blunt cardiac injury. J Trauma 73(5):S301-S306, 2012 32. Restrepo CS, Gutierrez FR, Marmol-Velez JA, et al: Imaging patients with cardiac trauma. Radiographics 32(3):633-649, 2012

Multidetector computed tomography of nonosseous thoracic trauma.

Multidetector computed tomography of nonosseous thoracic trauma. - PDF Download Free
2MB Sizes 0 Downloads 4 Views