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.     

Imaging of acute traumatic injuries of the thoracic aorta

Blunt traumatic aortic injuries are a major concern in the settings of high-speed deceleration accidents, since they are associated with a very high mortality rate; however, with prompt diagnosis and surgery, 70% of the patients with a blunt aortic lesion who reach the hospital alive will survive. This statement challenges the emergency radiologist in charge to evaluate the admission radiological survey in a severe chest trauma patient. With a 95% negative predictive value for the identification of blunt traumatic aortic lesions, plain chest film represents an adequate screening test. If aortography remains the gold standard, it tends, at least in hemodynamically stable trauma patients, to be replaced by spiral-CT angiography (SCTA), which demonstrates a 96.2% sensitivity, a 99.8% specificity, and a 99.7% accuracy. In unstable patients, trans-esophageal echography (TEE) plays a major diagnostic role. Knowledge of advantages and pitfalls of these imaging techniques, as reviewed in this article, will help the emergency radiologist to choose the appropriate algorithm in the diagnosis of traumatic aortic injury, for each trauma patient.     

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.     

A case of acute abdominal aortic dissection caused by blunt trauma

We present the case of an 18-year-old man involved in a fall with blunt abdominal trauma. The patient had hypovolemic shock and findings of an acute abdomen. Initial computed tomography (CT) showed pulmonary contusion, pneumohemothorax, hemoperitoneum, hepatic contusion, right kidney laceration and vascular avulsion, rupture of the mesenteric vein, rupture of the right rectus muscle with bowel hernia, and infrarenal aortic dissection. There were no signs of limb or medullar ischemia. After hemodynamic stabilization and surgical repair of the associated lesions, the dissection was successfully treated with a self-expanding aortic Wallstent. Postprocedure CT showed a well-positioned patent stent and the patient was discharged asymptomatic. Percutaneous endovascular stent implantation is minimally invasive and seems to be a safe treatment for traumatic dissection of the abdominal aorta.     

Computed tomography of thoracic aortic trauma

During a 63-month period, 28 consecutive patients suspicious for injury of the thoracic aorta were examined by computed tomography (CT) Twelve ve aortic ruptures were evidenced; pseudoaneurysm and mediastinal haematoma III close contact with the aorta were present In 12 atients, marginal lucency in 9, marginal irregularity in 8 and intimal flap in 6. CT was falsely negative in 1 patient with in jury (d lhc lull subclavian artery. Angiography and surgery confirmed the diagnosis in ? patients, and surgery alone in patients. CT had a sensitivity of 92% and a specificity of 100. The need for angiography was obviated in 67% of patients. A radiologist with experience in trauma management, CT und angiography should perform both examinations.     

Value of contrast-enhanced CT for managing mesenteric injuries after blunt trauma: review of five-year experience

Objective: The purpose of this retrospective study was to determine the value of contrast-enhanced computed tomography (CT) in the detection and management of mesenteric injuries after blunt trauma. Materials and methods: Between June 1995 and December 2000, 1,619 consecutive abdominal CT examinations were performed in the setting of major blunt trauma. Findings at CT were evaluated before patients were classified as having grade 1 or grade 2 lesions or none. Grade 1 represented the presence of minor injuries: mesenteric haziness, confined fluid, and/or small hematomas (<30 mm) within the mesenteric folds and abdominal injuries; grade 2 was appropriate to evidence of major injuries: moderate to large hematomas (>30 mm), active bleeding, hemoperitoneum, and further abdominal injuries. Results: On the basis of the CT findings, 161 (9.9%) of 1,619 patients were classified as having grade 1 and 25 (1.5%) of 1,619 patients as having grade 2 injuries. Of the 161 (77.6%) patients with grade 1 injuries, 125 were managed conservatively, while 36 (22.4%) underwent surgery. Of the 25 (84%) patients with grade 2 injuries, 21 were treated surgically and 1 (4%) patient was followed medically. Three (12%) of the 25 patients underwent laparotomy after 24 h close clinical observation and monitoring. Initial CT findings in 1,433 (88%) of the 1,619 patients were negative for mesenteric injuries, and in 1,430 of these cases no delayed mesenteric hemorrhage was observed. Conclusion: Contrast-enhanced CT has a critical role in the identification and exclusion of mesenteric injuries. Persistent, active extravasation of contrast material, in isolation or associated with further abdominal lesions, is a sign of a high likelihood of injury requiring urgent laparotomy. Haziness, isolated confined clotted mesenteric hemorrhage, and small hematomas within the mesentery are nonspecific findings and should be considered in the appropriate clinical context. Close clinical observation, monitoring, and surgical expertise are mandatory for appropriate management. Electronic Publication     

<Emphasis Type="Bold">Multi-detector computed tomography findings of atypical blunt traumatic aortic injuries: a pictorial review</Emphasis>

Traumatic injuries to the aorta are a significant source of morbidity and mortality in trauma patients, which highlights the importance of rapid diagnosis and treatment. Multi-detector row computed tomography has become the primary imaging modality for the imaging assessment of the polytrauma patient because it is fast, noninvasive, and the data sets can be used to create tailored multi-planar reformatted images that optimally display the location and morphology of aortic trauma and its relationship to adjacent structures. Although the classic location of blunt injury to the aorta occurs just distal to the left subclavian artery, aortic injuries may occur at any location along the aorta and in any patient population. Radiologists should be prepared to evaluate these types of injuries in nontraditional planes that are tailored to each examination and to present the data to clinicians using commercially available 3D software for purposes of surgical planning. Here, we review in pictorial form atypical aortic injuries with emphasis on multi-planar reformations.     

Delayed rupture of abdominal aortic false aneurysm following blunt trauma

Blunt injury of the abdominal aorta resulting in pseudoaneurysm formation is very rare. Such a pseudoaneurysm may rupture at any time, usually with fatal outcome. We report the case of a 32-year-old man with a clinically unsuspected ruptured abdominal aorta pseudoaneurysm, which had probably formed 3 years earlier, and emphasize the CT features. Electronic Publication     

Making the transition: the role of helical CT in the evaluation of potentially acute thoracic aortic injuries

OBJECTIVE: The purpose of this study was to show that helical CT could be used at our center in lieu of routine aortography to examine patients who have had serious blunt chest trauma. We also wanted to assess the potential savings of using CT to avoid unnecessary aortography. MATERIALS AND METHODS: The institutional review board approved the parallel imaging-CT immediately followed by aortography-of patients presenting with blunt chest trauma between August 1997 and August 1998. To screen patients for potential aortic injuries, we performed parallel imaging on 142 patients, and these patients comprised our patient population. CT examinations of the patients were reviewed for signs of injury by radiologists who were unaware of each other's interpretations and the aortographic results. Findings of CT examinations were classified as negative, positive, or inconclusive for injury. Aortography was performed immediately after CT. The technical and professional fees for both transcatheter aortography and helical CT were also compared. RESULTS: Our combined kappa value for all CT interpretations was 0.714. The aortographic sensitivity and negative predictive value were both 100%. Likewise, the sensitivity and negative predictive value of CT were 100%. The total costs of performing aortography were estimated at approximately $402,900, whereas those for performing helical CT were estimated at $202,800. CONCLUSION: Helical CT has a sensitivity and negative predictive value equivalent to that of aortography. Using CT to eliminate the possibility of mediastinal hematoma and to evaluate the cause of an abnormal aortic contour in a trauma patient allows us to use aortography more selectively. Avoiding the performance of unnecessary aortography will expedite patient care and reduce costs. We report the results of our experience with CT and how our center successfully made this transition in the initial examination of patients with serious thoracic trauma.     

阴囊闭合性损伤的CT诊断价值

目的　探讨阴囊、睾丸闭合性损伤的CT诊断价值。方法　急性阴囊闭合性损伤 9例 ,作CT横断面平扫检查。结果　阴囊闭合性损伤CT表现为 :阴囊肿大 7例 ;肉膜增厚模糊 9例 ;鞘膜腔积液 4例 ;睾丸肿大、实质内出血 8例 ;睾丸白膜破裂 5例、白膜下血肿 2例 ;阴囊隔肿胀偏移 7例。结论　用CT横断面平扫检查急性阴囊闭合性损伤病人是一种精确诊断睾丸及其被膜损伤的影像学检查方法。     

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.     

Endovascular stent-graft as a bridge to definitive repair of aortic trauma

We report a case of traumatic rupture of the thoracic aorta immediately treated with endovascular covered stent placement. Follow-up demonstrated a small endoleak, and because of the improved overall condition of the young patient a conventional repair was performed. The stent-graft provided an acute, minimally invasive therapeutic option.     

Multidetector-row CT of right hemidiaphragmatic rupture caused by blunt trauma: a review of 12 cases

AIM: To determine the usefulness of multidetector-row CT (MDCT) with multiplanar reformatted (MPR) images in the sagittal and coronal plane in diagnosing acute right hemidiaphragmatic rupture. MATERIALS AND METHODS: Twelve patients were identified who received chest and abdominal MDCT after major blunt trauma diagnosed with right diaphragmatic injury. Sagittal and coronal reformations were performed in all cases. The images were retrospectively reviewed by two experienced radiologists for signs of right diaphragm injury, such as direct diaphragm discontinuity, the "collar sign", the "dependent viscera sign", and intra-thoracic location of herniated abdominal contents. RESULTS: Of the 12 cases of right hemidiaphragm rupture, diaphragm discontinuity was seen in seven (58%) cases, the collar sign in five (42%), the dependent viscera sign in four (33%), and transdiaphragmatic herniation of the right colon and fat in another. Two variants of the collar sign were apparent on high-quality sagittal and coronal reformations. The first, termed the "hump sign", describes a rounded portion of liver herniating through the diaphragm forming a hump-shaped mass, and the second, termed the "band sign," is a linear lucency across the liver along the torn edges of the hemidiaphragm. The hump sign occurred in 10 (83%) patients and the band sign in four (33%). CONCLUSION: MDCT is very useful in the diagnosis of right hemidiaphragm injury caused by blunt trauma when sagittal and coronal reformatted images are obtained, and should allow more frequent preoperative diagnosis.     

螺旋CT血管造影在主动脉病变中的应用

目的评价螺旋ＣＴ血管造影在主动脉病变中的作用。方法４２例主动脉病变患者进行了螺旋ＣＴ增强扫描,其中包括主动脉夹层、主动脉瘤、假性动脉瘤、主动脉缩窄和离断、大动脉炎。应用５ｍｍ床进速度和３或５ｍｍ层厚（螺距＝１．６７或１）进行扫描,在工作站进行各种重建。结果１４例主动脉夹层,多平面重组（ＭＰＲ）较好地显示夹层和血栓范围以及弓部血管受累情况;表面覆盖显示（ＳＳＤ）见内膜片呈螺旋状剥离,不能区分真假腔;最大密度投影（ＭａｘＩＰ）不能提供更多的信息。２２例腹主动脉瘤（ＡＡＡ）,ＳＳＤ清晰显示动脉瘤的范围和与周围血管的关系;ＭＰＲ显示壁内血栓的范围;ＭａｘＩＰ则显示了血管壁的钙化和血管内支架的位置及支架周围情况。ＭＰＲ较好显示了假性动脉瘤与管腔的关系及动脉破口。３例先天性主动脉病变,ＳＳＤ能清晰显示血管的连接关系,而ＭａｘＩＰ和ＭＰＲ不能提供更多的信息。结论螺旋ＣＴ血管造影是评价主动脉病变较好的影像方法,可为临床治疗提供更多的信息     

A correlative study of aortic valve rotation angle and thoracic aortic sizes using ECG gated CT angiography

ObjectiveVarious degrees of aortic valve rotation may be seen in individuals with no history of congenital cardiovascular malformations, but its association with aortic sizes has not been studied.MethodsGated computed tomographic (CT angiograms in 217 patients were studied (66.7 ± 15; 22–97 years old)). Aortic diameters were determined at 5 anatomic locations. The length of the aorta from sinus to left subclavian artery was measured. The angle of valve rotation was recorded by measuring the angle between a line connecting the midpoint of the non-coronary sinus to the anterior commissure and another line along the interatrial septum. Rotation angles were correlated with aortic measurements. Patients were separated into two groups based on aortic sizes and into three groups based on age. The threshold for aortic dilatation was set at maximum ascending aorta diameter ≥40 mm (≥21 mm body surface area [BSA] indexed).ResultsNo significant difference in rotation angles was seen between the three age groups or between genders. Rotation angles were significantly correlated with maximal, average, and BSA adjustment of the aortic root and ascending aortic measurements. The aortic root angles were significantly different between the dilated versus nondilated aortas. There was no significant association between the rotation angles and age, length of ascending aorta, or diameters of descending aorta. Multivariate adaptive regression splines showed 25° of aortic root rotation as the diagnostic cut off for ascending aorta dilation. Above the 25° rotation, every 10° of increasing rotation was associated with a 3.78 ± 0.87 mm increase in aortic diameter (p < 0.01) and a 1.73 ± 0.25 times increased risk for having a dilated aorta (p < 0.01).ConclusionRotation angles of the aortic valve may be an independent non-invasive imaging marker for dilatation of the ascending aorta. Patients with increased rotation angle of the aortic valve may have higher risk for development or acceleration of an ascending aortic dilatation.     

Complex,traumatic rupture of the thoracic aorta in a child: diagnostic findings and delayed surgery

We report the unusual case of a 4-year-old girl with traumatic aortic rupture. A conventional chest X-ray showed an enlarged mediastinum. Spiral CT and transthoracic echocardiography demonstrated a mediastinal hematoma, bilateral pleural effusion, and a rupture of the aortic arch. Semi-elective surgery, 4 days after the accident, confirmed rupture of the aortic arch with dislocation of the left carotid artery and the Ductus of Botalli. The vessels were subsequently repaired without complication. After a follow-up of 10 months, the child has fully recovered.