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.     

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.     

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.     

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.     

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.     

Atypical results of thoracic aortography performed to exclude aortic injury

This study was undertaken to determine the incidence and spectrum of “equivocal” findings on thoracic aortography performed: (a) to exclude traumatic aortic injury (TAI), and (b) to identify radiologic signs that might be useful in increasing diagnostic confidence. All cases of thoracic aortography performed during a 5-year period to evaluate possible major thoracic arterial injury were identified. Those with atypical or uncertain results were reviewed by the authors, and medical records were analyzed to determine initial diagnosis, management course, and clinical outcome. During the study period, 438 thoracic aortograms were performed, of which 45 (10.3%) had surgically proven aortic injury and another 7 (1.6%) had surgically verified injury to proximal aortic branches. Twenty-four of those 438 patients (5.5%) had atypical or uncertain findings on aortography. Of the 24 patients, 10 had findings suggestive of aortic ulceration rather than TAI, 8 had a diagnosis of atypical ductus diverticulum, and 6 were diagnostically confusing for various reasons. Among the 24 cases, 16 patients ultimately were diagnosed as true-positive for TAI based on surgical confirmation, representing 35% of all ruptured aortas diagnosed during the study. Three studies were true-negative based on observation and follow-up angiography. There was one false-positive and two false-negative diagnoses based on surgical findings. Two patients with a presumptive diagnosis of TAI were observed because of their advanced age. Atypical or equivocal angiographic results occur in approximately 5% of the blunt trauma patients studied for potential TAI, but occur in about one third of such patients ultimately proven to have TAI. Some radiologic clues are suggested to increase diagnostic confidence in interpreting atypical aortographic findings. Management approaches also are suggested for cases in which the results remain uncertain.     

Aortography in the diagnosis of traumatic aortic rupture due to blunt chest trauma. Report of thirty-six cases.

Thirty-six patients were evaluated by aortography after blunt chest trauma with a suspicion of traumatic aortic rupture (TAR). There were 16 isolated TARs at isthmus, 2 multiple injuries both of the thoracic aorta and brachiocephalic arteries and no false negative aortographies. Seventeen aortographic examinations were negative, as confirmed by clinical and radiological follow up one false positive aortography was due to a ductus diverticulum. Aortography had a sensitivity of 100%, specificity of 94.4%, and accuracy of 97.2%. No complications or deaths resulted from angiography. Aortography is a safe, accurate and rapid technique to evaluate patients with suspicion of TAR; aortography is superior to other non-invasive techniques in depicting vascular anatomy and pathology, knowledge of which is essential for surgical planning.     

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.     

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.     

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

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

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.     

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.     

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.     

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

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

Traumatic injuries: imaging of thoracic injuries

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

Intravascular sonography in the assessment of traumatic injury of the thoracic aorta.

OBJECTIVE: The objective of this study is to describe the use of intravascular sonography in the evaluation of suspected injury of the thoracic aorta as an adjunctive tool to digital subtraction arteriography (DSA). SUBJECTS AND METHODS: Images of the thoracic aorta were obtained using DSA and intravascular sonography in 20 consecutive patients who underwent arteriography after chest trauma. A 6-French, 12.5-MHz sonography catheter was used for the intravascular sonography study. Diagnoses based on the review of both studies were compared. RESULTS: Five of 20 patients had aortic or great vessel injuries confirmed by surgery. Intravascular sonographic findings were positive (one false-positive) in seven patients, whereas DSA findings were positive in six patients (one false-positive and one false-negative). Surgery showed the lesion that was false-positive using both techniques to be a ductus diverticulum. Intravascular sonographic findings included intimal flaps, intramural lesions (hematomas), pseudoaneurysms, and perivascular hematomas. CONCLUSION: In our initial limited experience, intravascular sonography of the thoracic aorta and great vessels effectively identified traumatic injuries. Intramural injury without pseudoaneurysm formation or obvious intraluminal flap was visualized by intravascular sonography in one patient but was not detected by DSA. On the other hand, a ductus diverticulum was erroneously interpreted as trauma using both techniques. Intravascular sonography is a relatively new procedure with an obvious learning curve in the interpretation of the findings. An atypical ductus diverticulum may still be mistakenly interpreted as a sign of traumatic injury of the aorta. Familiarity with intravascular sonography in the setting of aortic trauma is necessary for correct interpretation of the images. The sonographic findings offer views of the aorta that are complementary to those of aortography.     

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.     

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).     

Mediastinal-width/chest-width ratio in blunt chest trauma: a reappraisal

The chest radiographs of 54 patients with blunt chest trauma and suspected aortic rupture were reviewed retrospectively. A mediastinal-width/chest-width ratio was calculated at the level of the aortic arch. There were 44 patients without evidence of aortic rupture on aortography or surgical exploration and 10 patients with surgically confirmed aortic rupture. There was no identifiable ratio of significance in distinguishing those with aortic rupture and those without rupture. The mediastinal-width/chest-width ratio is of insufficient sensitivity and specificity in confirming or excluding aortic rupture to be clinically useful.