Helical CT of diaphragmatic rupture caused by blunt trauma

OBJECTIVE: The purpose of this study was to determine the diagnostic sensitivity and specificity of helical CT with sagittal and coronal reformatted images in detecting diaphragmatic rupture after blunt trauma. MATERIALS AND METHODS: Chest and abdominal helical CT scans obtained in 41 patients with suspected diaphragmatic injury after major blunt trauma were reviewed by three observers who were unaware of surgical findings. Coronal and sagittal reformatted images were reviewed for each patient as well. Findings consistent with diaphragmatic injury, such as waistlike constriction of abdominal viscera (i.e., the "collar sign"), intrathoracic herniation of abdominal contents, and diaphragmatic discontinuity were recorded. Sensitivity and specificity of helical CT were calculated on the basis of surgical findings and clinical follow-up. RESULTS: Helical CT was performed preoperatively in 23 patients with diaphragmatic rupture (left, n = 17; right, n = 5; bilateral, n = 1). An additional 18 patients underwent helical CT to further evaluate suspicious findings seen on chest radiography at admission and were found to have an intact diaphragm. Sensitivity for detecting left-sided diaphragmatic rupture was 78% and specificity was 100%. Sensitivity for the detection of right-sided diaphragmatic rupture was 50% and specificity was 100%. The most common CT finding of diaphragmatic rupture was the collar sign, identified in 15 patients (sensitivity, 63%; specificity, 100%). Diaphragmatic discontinuity was seen in four patients. CONCLUSION: Helical CT, especially with the aid of reformatted images, is useful in the diagnosis of acute diaphragmatic rupture after blunt trauma. Helical CT can be used to detect 78% of left-sided and 50% of right-sided injuries.     

The dangling diaphragm sign: sensitivity and comparison with existing CT signs of blunt traumatic diaphragmatic rupture

The objectives of our study were to describe a new CT sign of diaphragmatic injury, the “dangling diaphragm” sign, and assess its comparative utility relative to other signs in the diagnosis of diaphragmatic injury resulting from blunt trauma. CT scans of 16 blunt trauma patients (12 men and four women, mean age 36.6 years old) with surgically proven diaphragmatic injury and 32 blunt trauma patients (24 men and eight women; mean age 37.4 years old) without evidence of diaphragmatic injury at surgery were blindly reviewed by three board certified radiologists specializing in body imaging. Studies were evaluated for the presence of established signs of diaphragmatic injury, as well as the dangling diaphragm sign, in which the free edge of the torn hemidiaphragm curls inward from its normal course parallel to the body wall. The sensitivity and specificity of each sign were determined, as were the correlation between the signs and the interobserver agreement in evaluation of these findings. The radiologists’ overall impression as to whether rupture was present was also recorded. In select cases, coronal and/or sagittal reformatted images were available, and they were reviewed following evaluation of the original axial images. Any change in interpretation due to these images was noted. The sensitivity of the radiologists’ overall impression for detection of diaphragmatic injury was 77%, with 98% specificity. Individual signs of diaphragmatic injury had sensitivities ranging from 44% to 69%, with specificities of 98% to 100%. The dangling diaphragm sign had a sensitivity of 54% and a specificity of 98%, similar to the other signs. Multiple signs were present in most cases of diaphragmatic injury, and coronal and sagittal reformatted images had little impact. Diaphragmatic injury remains a challenging radiographic diagnosis. The dangling diaphragm is a conspicuous sign of diaphragmatic injury, and awareness of it may increase detection of diaphragmatic injury on CT studies.     

Traumatic rupture of the right hemidiaphragm: Diagnosis by chest radiography

Sixteen cases of blunt trauma resulting in surgically confirmed traumatic rupture of the right hemidiaphragm were reviewed from the Trauma Registry of Allegheny General Hospital. Only 10 of the 16 cases (63%) could be retrospectively diagnosed on chest radiographs. We found that a diagnosis of right-sided diaphragmatic rupture can be suggested when the apex of the right hemidiaphragm is shifted superomedially to a position approximately midway between the mediastinum and the right chest wall. Eight of these 10 cases with positive chest radiographic findings exhibited this superomedial shift of the diaphragmatic apex. On initial assessment, without using this sign, 5 of these 10 cases were not diagnosed. We feel that the combination of elevation of the right hemidiaphragm in association with a medial shift of the apex of that diaphragmatic dome in a patient who has suffered extensive blunt thoracoabdominal trauma is strongly suggestive of traumatic rupture of the diaphragm.     

The "dependent viscera" sign in CT diagnosis of blunt traumatic diaphragmatic rupture

OBJECTIVE: The objective of our study was to describe the "dependent viscera" sign and determine its usefulness at CT in the diagnosis of diaphragmatic rupture after blunt abdominal trauma. MATERIALS AND METHODS: The study sample consisted of 28 consecutive patients (19 men, nine women) between 17 and 74 years old (mean age, 31 years) who had undergone abdominal CT and subsequent emergency laparotomy after a blunt trauma. Ten patients had a diaphragmatic rupture (six, right-sided; four, left-sided) at laparotomy. An experienced radiologist unaware of the surgical findings retrospectively reviewed the CT scans, and then a second radiologist reviewed the scans to provide interobserver agreement. Note was made of discontinuity of the diaphragm, intrathoracic herniation of abdominal contents, and waistlike constriction of bowel (the collar sign). Also noted was whether the upper one third of the liver abutted the posterior right ribs or whether the bowel or stomach lay in contact with the posterior left ribs. Either of these findings was termed the "dependent viscera" sign. The radiologists' detection rate of diaphragmatic rupture on the CT scans via observance of the dependent viscera sign was determined. Interobserver agreement was assessed using Cohen's kappa statistic. RESULTS: The dependent viscera sign was observed on the CT scans of 100% of the patients with a left-sided diaphragmatic rupture and of 83% of the patients with right-sided diaphragmatic rupture. Both observers missed one case of right-sided diaphragmatic rupture. The radiologists' overall rate of detecting diaphragmatic rupture was 90% using the dependent viscera sign. We found excellent interobserver agreement (kappa = 1) for detection of the dependent viscera sign and for the diagnosis of diaphragmatic tear on CT scans. CONCLUSION: The dependent viscera sign increases the detection at CT of acute diaphragmatic rupture after blunt trauma.     

多层螺旋CT多平面重组诊断创伤性膈肌破裂

目的 探讨MSCT MPR方法诊断创伤性膈肌破裂(traumatic diaphragmatic rupture,TDR)的价值.方法 21例手术证实TDR,15例排除TDR的胸腹部创伤患者术前MSCT图像,由3名高年资医师先后对MSCT横断面和MPR图像行盲法回顾分析,以发现横膈异常升高、膈肌中断缺损及"颈圈征"作为TDR诊断依据.对照手术结果计算MSCT横断面及MPR诊断TDR的敏感度、特异度、阳性预测值、阴性预测值和准确度;MSCT横断面和MPR对膈肌中断缺损、"颈圈征"的辨认率差异及其诊断TDR的敏感度、特异度差异采用McNemar检验.结果 MSCT横断面诊断TDR的敏感度、特异度、阳性预测值、阴性预测值和准确度分别为71%(15/21)、80%(12/15)、83%(15/18)、67%(12/18)和75%(27/36);MPR分别为86%(18/21)、93%(14/15)、95%(18/19)、82%(14/17)和89%(32/36).21例TDR中,MSCT显示膈肌中断、缺损横断面12处(9例),采用MPR重组方法除显示上述12处外,还进一步显示8处(6例),共20处(15例),差异无统计学意义(P=0.125).MSCT横断面显示"颈圈征"6例,MPR方法显示14例,二者差异有统计学意义(P=0.021).MSCT横断面上观察膈肌中断缺损诊断TDR的敏感度、特异度分别为43%(9/21)和80%(12/15),MPR分别为71%(15/21)和93%(14/15),差异均无统计学意义(P值分别为0.125和0.500).MSCT横断面上观察"颈圈征"诊断TDR的敏感度、特异度分别为29%(6/21)和100%(15/15),MPR分别为67%(14/21)和100%(15/15),敏感度差异有统计学意义(P=0.021),特异度差异无统计学意义(P=1.000).结论 MSCT诊断TDR具有良好的敏感度、特异度和准确度;MPR是横断面诊断TDR的重要补充,有助于提高TDR诊断水平.     

Right diaphragmatic rupture and hepatic hernia: an indirect sign on computed tomography

We report a case of blunt traumatic right diaphragm rupture with hepatic hernia. The diagnosis was first suggested by an abnormal hepatic location depicted on axial CT. This finding can be considered as a potentially new indirect sign of right diaphragm rupture in patients with blunt trauma. The diagnosis was then confirmed by reformatted CT and MR images. Received: 2 June 1998; Revision received: 5 August 1998; Accepted: 25 August 1998     

Multidetector computed tomography of diaphragm: Anatomic variants and diagnostic problems in adult population

ObjectiveAssess the multidetector computed tomography (MDCT) in the anatomic appearance of the diaphragm, its variants and defects.Materials and methodsRetrospective study of 142 scans of patients in their 20s–80s using 64 rows MDCT from January 2010 to March 2011. According to Gale (1986), anterior diaphragm appearance on axial image is classified into type 1: continuous, type 2: discontinuous, and type 3: broad. Sagittal reformatted image is classified into type A: downward slope, type B: upward slope, and type C: flat. According to Caskey et al. (1989), posterior diaphragm defects are classified into type 1: localized defect with maintenance of its continuity, type 2: defect in parallel layers with maintenance of its continuity and type 3: loss of diaphragmatic continuity.ResultsAnterior diaphragm was assessed in 141 cases. On axial images, types 1, 2, and 3 were found in 36.9%, 41.1%, and 22.0% respectively. On sagittal reformatted images, types A, B, and C were found in 32.6%, 41.1%, and 26.2% respectively. One case had Morgagni hernia. Significant relationship between the types at the axial and sagittal images was found (r = 0.205, P < 0.05). 2.8% Posterior diaphragmatic defects. High significant relationship between the age and diameter of oesphageal hiatus was found (P < 0.05).ConclusionThe multiplanar capability of MDCT is adding a new scope of assessment of diaphragm and its variants.     

创伤性膈肌破裂的诊断与治疗

目的 探讨创伤性膈肌破裂的早期诊断和治疗.方法 回顾性分析我科17年间收治的161例创伤性膈肌破裂患者的临床资料,包括诊断方法、术前确诊率、膈疝发生率、手术治疗方式和患者结局等.结果 161例中男139例,女22例;年龄9～84岁,平均32.4岁.ISS 13～66分,平均27.8;65.2%入院时有休克.钝性伤36例、穿透伤125例.术前膈肌损伤确诊率在钝性和穿透伤分别为88.9%和78.4%.膈疝发生率在钝性和穿透伤分别为94.4%和14.4%(P＜0.01).手术经胸30例,经腹106例,分别剖胸和剖腹18例、胸腹联合切口7例.病死率10.6%,ISS平均41.6;主要死因为失血性休克和严重感染并发症.钝性和穿透伤病死率分别为22.2%和7.2%(P＜0.01).结论 膈伤诊断依据,钝性伤主要为膈疝的影像学表现,穿透伤伤口远处腹或胸部也有阳性体征或影像学征象.膈疝手术的关键是准确判断疝入胃肠的活力.穿透伤预后相对较好.     

Sinus cut-off sign: a helpful sign in the CT diagnosis of diaphragmatic rupture associated with pleural effusion

The objective of our study was to describe the "sinus cut-off" sign at CT in the diagnosis of diaphragmatic rupture in patients with blunt abdominal trauma complicated with pleural effusion, and evaluate its utility in an experimental model. Between January 2004 and March 2005, we observed an unusual interruption of costophrenic sinus at CT in three patients with blunt abdominal trauma accompanied with pleural effusion. This observation prompted us to evaluate the utility of this sign in an experimental model. Laparotomically, we created 2 cm diapragmatic lacerations at each hemidiaphragm in two rabbits and pushed up the abdominal viscera with omentum through the defect. To simulate hemothorax, we also injected 5-10 mL of diluted contrast material into the pleural space. Using a dual-slice helical CT scanner, limited thoracoabdominal CT examination was performed before and after injection of intrapleural contrast material. The images were analyzed for the presence of CT signs for diaphragmatic injury. The left posterior costophrenic sulcus was interrupted in all of the three patients with left pleural effusion. While it was associated with other findings of diaphragmatic injury, the "sinus cut-off sign" was the sole finding in one patient. The sinus cut-off sign was observed on the CT scans of 100% of the rabbits with a left and right sided diaphragmatic rupture. The "sinus cut-off sign" is useful and can increase the CT detection of acute diaphragmatic injury associated with pleural effusion.     

Imaging hemidiaphragmatic injury

The supine chest radiograph is the initial and most commonly performed imaging study to evaluate the thorax after trauma. Whenever the chest radiograph is equivocal or suspicious for acute diaphragmatic injury (DI), computed tomography (CT) is usually the next study of choice since it is both generally available and often used to examine other body regions in the patient after trauma. CT is usually diagnostic, particularly if supplemented by multiplanar reformation (MPR) obtained using thin-slice axial scanning and overlapping images for reformations. Magnetic resonance imaging (MRI) is potentially useful to assess the diaphragm if CT findings are indeterminate and the patient is stable enough to have the procedure. Simple T1-weighted spin-echo images in the sagittal and coronal orientation are usually sufficient to establish or exclude DI. This article reviews imaging modalities and strategies for diagnosing DI from blunt trauma.     

Helical CT with sagittal and coronal reconstructions: accuracy for detection of diaphragmatic injury

OBJECTIVE: The objectives of our study were to determine the accuracy of single-detector helical CT (including coronal and sagittal reconstructions) for the diagnosis of traumatic diaphragmatic injury, establish measurements for the thickness of the normal diaphragmatic crus, and describe an additional sign of diaphragmatic injury: active arterial extravasation of contrast material at the level of the diaphragm. MATERIALS AND METHODS: The CT scans of 25 patients with surgically proven diaphragmatic injury and 22 patients with surgically confirmed uninjured diaphragms were blindly reviewed by five thoracic radiologists. Sagittal and coronal reconstructions were performed for 20 of the 25 patients with a proven diaphragmatic injury and for all the patients without a diaphragmatic injury. Scans were evaluated for findings suggestive of diaphragmatic injury and for associated injuries. Reviewers scored the usefulness of the reconstructed images for establishing the final diagnosis. Measurements of the right and left crura were performed to establish a threshold measurement that would enable radiologists to discriminate between a normal diaphragm and an injured diaphragm. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of helical CT were 84%, 77%, 81%, 81%, and 83%, respectively. Scans showing active arterial extravasation of contrast material enabled reviewers to correctly identify diaphragmatic injury in two patients. Reconstructed images confirmed the correct diagnosis in three patients but supported an incorrect diagnosis in two. The mean thickness of the diaphragmatic crura (right and left) was not significantly greater in patients with an injured diaphragm than in those with an uninjured diaphragm. CONCLUSION: Helical CT shows good sensitivity, specificity, and accuracy for the diagnosis of diaphragmatic injury. Coronal and sagittal reconstructions are of limited use in establishing or refuting this diagnosis. Active arterial extravasation of contrast material near the diaphragm should raise suspicion for injury. Crus measurements cannot be used to reliably distinguish between injured and uninjured diaphragms.     

Spiral CT findings in a postoperative intrathoracic gastric herniation: a case report

A case is reported in which spiral CT was most the contributive imaging technique in the diagnosis of a postoperative intrathoracic gastric herniation. The coronal reformatted spiral CT images demonstrated very well the intrathoracic stomach located above a normally positioned left hemi-diaphragm. Compared with conventional CT, the multiplanar reconstruction capability provided by spiral CT allowed a much better delineation of the diaphragm in this case. Correspondence to: J. Bogaert     

Routine isotropic computed tomography scanning of chest: value of coronal and sagittal reformations

OBJECTIVE: We sought to evaluate the usefulness of coronal and sagittal reformations from isotropic chest computed tomography (CT) examinations. METHODS: A total of 30 chest CT examinations were reconstructed into 2 sets of axial source images: 0.9-mm slice width with 0.45-mm reconstruction interval (isotropic) and 4-mm slices with 3-mm reconstruction interval. The isotropic dataset was reformatted into coronal and sagittal stacks with 4-mm slices. Three readers reviewed the image sets with 4-mm slice widths. Coronal and sagittal reformations were compared at the same sitting to axial images for depiction of anatomy and disease in the aorta, pulmonary arteries, hilar regions, mediastinum, lung parenchyma, pleura, diaphragm, thoracic spine, ribs, and trachea. A 5-point scale was used to determine whether nonaxial reformations showed anatomy and disease significantly better, somewhat better, same, somewhat worse or significantly worse than equivalent thickness axial source images. A 3-point scale was used to score if nonaxial image sets showed no, some, or significant additional information compared with the axial plane regarding the main diagnosis. RESULTS: There was better visualization of the hilar regions, diaphragm, spine, and trachea on the coronal reformations compared with source axial images (P < 0.05). Sagittal reformations scored better than axial source images for aorta, pleura, diaphragm, spine, and ribs (P < 0.05). The coronal and sagittal series showed significant additional information in 11% and 9% of patients, respectively. CONCLUSION: Radiologists should consider the use of one or both of coronal and sagittal planes in addition to the axial series in routine interpretation of chest CT.     

Benefits of routine use of coronal and sagittal reformations in multi-slice CT examination of the abdomen and pelvis

AIM: To evaluate the usefulness of coronal and sagittal reformations from isotropic abdomino-pelvic computed tomography (CT) examinations. METHODS: Fifty consecutive abdomino-pelvic CT examinations were reconstructed into two sets of axial source images: 0.9 mm section width with 0.45 mm reconstruction interval (isotropic) and 4 mm section width with 3 mm reconstruction interval. The isotropic dataset was reformatted into coronal and sagittal stacks with 4 mm section widths. Three readers independently reviewed the three image sets with 4 mm section widths. The coronal and sagittal reformations were compared with the axial images, in the same sitting, for depiction of lesions in various abdominal organs. RESULTS: There was better visualization of lesions in the liver, kidneys, mesentery, lumbar spine, major abdominal vessels, urinary bladder, diaphragm and hips on the coronal reformations compared with source axial images (p<0.05). Sagittal reformations scored better than axial source images for showing lesions in the liver, thoracic spine, abdominal vessels, uterus, urinary bladder, diaphragm and hips (p<0.05). The coronal and sagittal series showed significant additional information in 23 and 17% of patients, respectively. CONCLUSION: Radiologists should consider the routine review of at least one additional plane to the axial series in the interpretation of abdomino-pelvic CT studies.     

Radiological evaluation of post-traumatic tracheal stenosis using multidetector CT with multiplanar reformatted imaging and virtual bronchoscopy: Comparison with intraoperative findings

Aim

To evaluate the diagnostic utility of multidetector computed tomography (MDCT) (axial, multiplanar reformatted images and virtual bronchoscopy) in preoperative assessment of post-traumatic tracheal stenosis.

Materials and methods

Twenty-four patients with post-traumatic tracheal stenosis underwent tracheal resection anastomosis. The diagnosis was ascertained on the basis of history and rigid-bronchoscopy. All patients were preoperatively evaluated by MDCT. Intraoperative findings were used as the gold standard. Lesions were evaluated in terms of site, distance from the vocal cords, length, grade of the stenosis and length of the planned resected segment.

Results

The sensitivity of MDCT was 100%, 100%, 92.3%, 92.3%, 96% and its accuracy was, 100%, 100%, 96%, 96%, 88.8% in assessment of tracheal stenotic site, distance from the vocal cords, length, length of segment planned for resection and stenotic grade, respectively. MPR (coronal and sagittal reformatted) images were 100% sensitive in detecting stenotic site and distance from the vocal cord. It showed 92.3% sensitivity and 96% accuracy in assessment of the stenotic segment length and the length of segment planned for resection. VB showed 96% sensitivity and 88.8% accuracy.

Conclusion

MDCT with its various display modes improved the preoperative evaluation of post-traumatic tracheal stenosis. The combined interpretation of axial, multiplanar reformatted and VE leads to improved diagnostic confidence. We recommend it as a constant demand for preoperative evaluation of post-traumatic tracheal stenosis.     

Sternal fracture in the emergency department: diagnostic value of multidetector CT with sagittal and coronal reconstruction images

Background

Multidetector CT (MDCT) is being increasingly used for patients with traumatic injuries in the emergency room. This is the first study to evaluate the diagnostic performance of MDCT for sternal fracture.

Patients and methods

For 87 patients who had motor vehicle accidents, we evaluated the diagnostic performance of MDCT for the sternal fractures. For 31 patients who underwent both MDCT and lateral radiography for the sternum, we compared the diagnostic performance of two examinations for the evaluation of sternal fracture.

Results

Thirty-two patients had sternal fractures and all the sternal fractures (sensitivity = 100%) were detected on MDCT, especially on the sagittal reconstruction images. However, the axial and coronal images detected 65% and 59% of all sternal fractures, respectively. For 31 patients who underwent both MDCT and lateral radiography for the sternum, MDCT showed superior diagnostic performance compared to that of radiography (accuracy = 97% and 77%, respectively, P = .02). For the one case that showed false positivity for sternal fracture on MDCT due to respiratory artifact, the lateral radiography enabled making the correct diagnosis.

Conclusion

Sternal fracture is frequently seen in patients who have blunt trauma injury secondary to motor vehicle accidents. MDCT, particularly sagittal images detect all of the sternal fractures, is superior to lateral radiography for diagnosis of sternal fracture. In the limited case that CT has severe motion artifact, additional radiography could help the diagnosis of sternal fracture.     

CT"内脏依靠征"对创伤性横膈破裂的诊断价值

目的：描述CT“内脏依靠征“,评价该征在腹部钝性外伤后横膈破裂的诊断价值。材料和方法：对10例经手术证实的外伤性膈疝病人的CT检查资料进行回顾性分析,评价“内脏依靠征“的诊断价值。结晶：依据“内脏依靠征“,CT明确诊断横膈破裂右侧3例,左侧6例,1例右侧破裂漏诊,总诊断准确率90％。结论：“内脏依靠征“很好地显示了横膈破裂的特征,有助于提高CT对腹部钝性外伤后横膈破裂的诊断准确率。     

Multidetector CT evaluation of abdominal trauma

CT is the imaging modality of choice to evaluate blunt abdominal trauma. With the advent of multidetector CT (MDCT), scanning times have progressively decreased while image resolution has increased owing to thinner collimation and reduced partial volume and motion artifacts. MDCT also allows high quality two-dimensional and three-dimensional multiplanar reformatted images to be obtained, which aid in the diagnosis of the complex multisystem injuries seen in the trauma patient. This article describes the authors' current imaging protocol with 16-detector MDCT, the spectrum of CT findings seen in patients with blunt abdominal injuries, and the role MDCT has in guiding injury management.     

Primary interpretation of thoracic MDCT images using coronal reformations

OBJECTIVE: The objective of this study was to evaluate the accuracy and efficiency of primary interpretation of thoracic MDCT using coronal reformations as compared with transverse images. SUBJECTS AND METHODS: Fifty patients (18 females, 32 males; age range, 15-93 years; mean age, 63.6 years) underwent 4-MDCT of the chest (detector width, 1 mm; beam pitch, 1.5). Contrast material was administered in 20 of the 50 patients. Coronal and transverse sections were reformatted into 5-mm-thick sections at 3.5-mm intervals. All available image and clinical data consensually reviewed by two thoracic radiologists served as the reference standard. Subsequently, three other thoracic radiologists independently evaluated reformatted coronal and transverse images at two separate review sessions. Each image set was assessed in 58 categories for abnormalities of the lungs, mediastinum, pleura, chest wall, diaphragm, abdomen, and skeleton. Interpretation times and number of images assessed were recorded. Sensitivity, specificity, and interobserver concordance were calculated. Differences in mean sensitivities and specificities were evaluated with Wilcoxon's signed rank test. RESULTS: The most common findings identified were pulmonary nodules (n = 73, transverse images; n = 72, coronal images) and emphysema (n = 45, transverse; n = 40, coronal). The mean detection sensitivity of all lesions was significantly (p = 0.001) lower on coronal (44% +/- 26% [SD]) than on transverse (51% +/- 22%) images, whereas the mean detection specificity was significantly (p = 0.005) higher (96% +/- 5% vs 95% +/- 6%, respectively). Reporting findings for significantly (p < 0.001) fewer coronal images (mean, 63.0 +/- 4.6 images) than transverse images (mean, 91.9 +/- 8.8 images) took significantly (p = 0.025) longer (mean, 263 +/- 56 sec vs 238 +/- 45 sec, respectively). CONCLUSION: Primary interpretation of thoracic MDCT is less sensitive and more time-consuming using 5-mm-thick coronal reformations as compared with transverse images.     

Acute tracheobronchial injuries: Impact of imaging on diagnosis and management implications

PURPOSE: To evaluate the role of chest radiography, single-slice CT and 16-row MDCT in the direct evidence of tracheobronchial injuries. METHODS: Patients with acute tracheobronchial injury were identified from the registry of our level 1 trauma center during a 5-year period ending July 2005. Findings at chest radiograph and CT were compared to those shown at bronchoscopy. RESULTS: Eighteen patients with tracheobronchial injury - three patients with cervical trachea injury, eight with thoracic trachea injury and seven with bronchial injury - were identified. Twelve patients had a blunt trauma (67%), six patients had a penetrating (iatrogenic) injury (33%). Chest radiograph directly identified the site of tracheal injury in four cases, showing overdistension of the endotracheal cuff in three cases and displacement of the endotracheal tube in one case. At the level of the bronchi, chest radiograph demonstrated only one injury. CT directly identified the site of tracheal injury in all the cases showing the overdistension of the endotracheal cuff at the level of the thoracic trachea (three cases), posterior herniation of the endotracheal cuff at the thoracic trachea (three cases), lateral endotracheal cuff herniation at the thoracic trachea (one case), tracheal wall discontinuity at the cervical (one case) and at the thoracic trachea (one case) and displacement of endotracheal tube at the cervical trachea (two cases). At the level of the bronchi, CT correctly showed the site of injury in six case including: discontinuity of the left main bronchial wall (two cases), the "fallen lung" sign (one case), right main bronchial wall enlargement (one case), discontinuity of the right middle bronchial wall (two cases). In one case, CT showed just direct "air leak" at the level of the carina suggesting main bronchus injury. This finding was confirmed by bronchoscopy. CONCLUSION: Chest radiograph was helpful for the assessment of iatrogenic tracheal injuries. CT detected the site of blunt tracheobronchial injuries in 94% of the cases. Multiplanar 16-row MDCT reconstructions, were essential for the optimal surgical approach.