Imaging Pearls ❯ Chest ❯ Trauma
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- Background: Radiology reporting of emergency whole-body computed tomography (CT) scans is time- critical and therefore involves a significant risk of pathology under-detection. We hypothesize a relevant number of initially missed secondary thoracic findings that would have been detected by an artificial intelligence (AI) software platform including several pathology-specific AI algorithms.
Methods: This retrospective proof-of-concept-study consecutively included 105 shock-room whole-body CT scans. Image data was analyzed by platform-bundled AI-algorithms, findings were reviewed by radiology experts and compared with the original radiologist’s reports. We focused on secondary thoracic findings, such as cardiomegaly, coronary artery plaques, lung lesions, aortic aneurysms and vertebral fractures.
Results: We identified a relevant number of initially missed findings, with their quantification based on 105 analyzed CT scans as follows: up to 25 patients (23.8%) with cardiomegaly or borderline heart size, 17 patients (16.2%) with coronary plaques, 34 patients (32.4%) with aortic ectasia, 2 patients (1.9%) with lung lesions classified as “recommended to control” and 13 initially missed vertebral fractures (two with an acute traumatic origin). A high number of false positive or non-relevant AI-based findings remain problematic especially regarding lung lesions and vertebral fractures.
Conclusions: We consider AI to be a promising approach to reduce the number of missed findings in clinical settings with a necessary time-critical radiological reporting. Nevertheless, algorithm improvement is necessary focusing on a reduction of “false positive” findings and on algorithm features assessing the finding relevance, e.g., fracture age or lung lesion malignancy.
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - Background: Radiology reporting of emergency whole-body computed tomography (CT) scans is time- critical and therefore involves a significant risk of pathology under-detection. We hypothesize a relevant number of initially missed secondary thoracic findings that would have been detected by an artificial intelligence (AI) software platform including several pathology-specific AI algorithms.
Methods: This retrospective proof-of-concept-study consecutively included 105 shock-room whole-body CT scans. Image data was analyzed by platform-bundled AI-algorithms, findings were reviewed by radiology experts and compared with the original radiologist’s reports. We focused on secondary thoracic findings, such as cardiomegaly, coronary artery plaques, lung lesions, aortic aneurysms and vertebral fractures.
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - Results: We identified a relevant number of initially missed findings, with their quantification based on 105 analyzed CT scans as follows: up to 25 patients (23.8%) with cardiomegaly or borderline heart size, 17 patients (16.2%) with coronary plaques, 34 patients (32.4%) with aortic ectasia, 2 patients (1.9%) with lung lesions classified as “recommended to control” and 13 initially missed vertebral fractures (two with an acute traumatic origin). A high number of false positive or non-relevant AI-based findings remain problematic especially regarding lung lesions and vertebral fractures.
Conclusions: We consider AI to be a promising approach to reduce the number of missed findings in clinical settings with a necessary time-critical radiological reporting. Nevertheless, algorithm improvement is necessary focusing on a reduction of “false positive” findings and on algorithm features assessing the finding relevance, e.g., fracture age or lung lesion malignancy.
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - “Based on 105 “shock-room” emergency CT scans, we demonstrated an AI system that would have decreased the number of missed secondary thoracic findings in an AI- assisted reading setting. The added clinical value could be quantified by the number of additional findings as follows: up to 25 (23.8%) patients with cardiomegaly or borderline heart size, 17 (16.2%) patients with coronary plaques, 34 (32.4%) patients with dilatations of the thoracic aorta, 13 additional vertebral fractures (two of them with an acute traumatic origin) and three lung lesions of two different patients that were radiologically classified as “in recommendation to control”.”
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - “In order to finally also address possible future AI applications in radiology: Our results support the idea that AI applications can assist the radiologist especially where detections, measurements and quantitative assessments are involved. The rapid and automatic detection of pathological lesions or pathological measurements is intended to reduce the rate of missed findings, but also enables quick triaging with regard to the radiologists’ reading list. Urgent cases can be presented to the radiologist in a prioritized manner after passing through AI software and thus, urgent medical interventions can be initiated earlier. The accurate assessment of image data facilitated by AI also enables the establishment of quantitative imaging biomarkers. In this way, information that is contained in image data but has not been taken into account so far can be of great use for the patient and the treating physician (for example in the form of “lab-like results”).”
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - “In conclusion, we demonstrated in a retrospective proof- of-concept setting the high potential of AI approaches to reduce the number of missed secondary findings in clinical emergency settings that require a very time-critical radiological reporting. In particular, the integration of different specialized algorithms in a single software solution is promising to avoid clinically too narrow AI applications. But also with regard to less urgent applications of medical imaging, it should be mentioned that especially non- radiology clinicians might even take more benefit from AI- assisted image analysis compared to anyway well-trained radiologists, e.g., in clinical settings without 24/7 radiology coverage or long turnaround times for radiology reporting. Although algorithms primarily need a high sensitivity to effectively reduce the number of initially missed CT findings, ongoing research should focus on algorithm improvements with regard to specificity to also reduce the number of FPs or non-relevant algorithm findings, which otherwise need to be manually ruled out by radiologists in a time-consuming procedure and also might affect radiologists’ clinical decision making.”
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - “In conclusion, we demonstrated in a retrospective proof- of-concept setting the high potential of AI approaches to reduce the number of missed secondary findings in clinical emergency settings that require a very time-critical radiological reporting. In particular, the integration of different specialized algorithms in a single software solution is promising to avoid clinically too narrow AI applications. But also with regard to less urgent applications of medical imaging, it should be mentioned that especially non- radiology clinicians might even take more benefit from AI- assisted image analysis compared to anyway well-trained radiologists, e.g., in clinical settings without 24/7 radiology coverage or long turnaround times for radiology reporting.”
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498 - “Although algorithms primarily need a high sensitivity to effectively reduce the number of initially missed CT findings, ongoing research should focus on algorithm improvements with regard to specificity to also reduce the number of FPs or non-relevant algorithm findings, which otherwise need to be manually ruled out by radiologists in a time-consuming procedure and also might affect radiologists’ clinical decision making.”
Reduction of missed thoracic findings in emergency whole-body computed tomography using artificial intelligence assistance
Johannes Rueckel et al.
Quant Imaging Med Surg 2021;11(6):2486-2498
- Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important.
Main body: Blunt thoracic aortic injury may be fatal if not diagnosed and treated expeditiously. Endovascular options allow safe and effective management of these dangerous injuries. This paper describes the overview of blunt thoracic aortic trauma, the epidemiology, presentation, diagnosis, and treatment options with a focus on endovascular management.
Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important. and treatment options with a focus on endovascular management.
Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - “Up to 80% of patients presenting with blunt thoracic aortic injury(BTAI) die before hospitalization, and in the remaining survivors, in- hospital mortality is as high as 46%. While this is a potentially lethal injury, it is rare and accounts for 1.5% of thoracic trauma.”
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - "Rapid deceleration is the universal mechanism of this injury. Most commonly, there are multiple other life- threatening injuries present with less than 20% having this as an isolated injury making the diagnosis and initial next steps challenging. BTAI is defined as a tear in the aorta that is a result of a combination of shear and stretch forces, rapid deceleration, increased intravascular pressure and compression of the aorta between the anterior chest wall and vertebrae.”
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - "Injury can occur along the entire length of the aorta, essentially from the ascending aorta to the iliac bifurcation, although the injury typically occurs areas of aortic tethering, notably the aortic isthmus.”
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - “Blunt thoracic aortic trauma is associated with other major entities of chest trauma, including, but not limited to, sternal fracture, 1st/2nd rib fractures, clavicle and/or scapular fractures, pneumothoraces, hemothoraces, flail chest, pulmonary contusions, diaphragm injury, tracheobronchial disruption and esophageal injuries; these should raise suspicion for BTAI.”
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - "Injuries are assigned one of 4 grades based on CTA imaging: grade 1 (intimal tear), grade II (intramural hematoma), grade III (pseudoaneurysm) and grade IV (rupture). Currently, the recommendation is to proceed with surgical repair of Grade II-IV injuries [20]. For grade I injuries, it is well established that no intervention is necessary as these tend to resolve on their own with conservative management. Grade II injures do fall into a “gray zone” between medical management and operative intervention although more recent studies do document that nonoperative is safe with close follow up.”
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - "Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular approaches have slowly replaced open surgical repair for the management of this pathology. Clearly, such patients that present with blunt thoracic injury should be relegated to centers that specialize in the polytrauma patient as it is their concurrent injuries that are the focus of their critical care.”
Blunt thoracic aortic injury – concepts and management
Nicolas J. Mouawad et al.
Journal of Cardiothoracic Surgery (2020) 15:62 - “The CT findings of TAI can be divided into direct signs of injury and indirect or associated findings. Direct findings of aortic injury include intramural hematoma, intimal flap and pseudoaneurysm. Injuries that only involve the intima, classified as minimal aortic injuries, should only have direct findings of TAI. Minimal aortic injuries can present with an intimal flap, intraluminal aortic thrombus or intramural hematoma. With the improvement in technology allowing thinner CT slice thickness minimal aortic injuries are being diagnosed more frequently.”
Traumatic aortic injury: CT findings, mimics, and therapeutic options
Ethany L. Cullen et al.
Cardiovasc Diagn Ther 2014;4(3):238-244 - "Ductal remnants, a diverticulum or small bump, are normal remnants of the embryologic ductus arteriosus. This normal variant can simulate injury and can be very perplexing for the inexperienced or unaware radiologist. The ductal diverticulum is a remnant of the closed or partially closed ductus arteriosus which connects the pulmonary artery to the aorta in fetal circulation. Ductal remnants are located at the inferior surface of the aortic arch near the aortic isthmus which leads to their confusion with TAIs. Ductal remnants are typically smooth walled and have obtuse margins that are continuous with the aortic wall and are often calcified. The presence of calcification can be very helpful in distinguishing a ductal remnant from a TAI with the presence of calcification favoring a benign ductal remnant.”
Traumatic aortic injury: CT findings, mimics, and therapeutic options
Ethany L. Cullen et al.
Cardiovasc Diagn Ther 2014;4(3):238-244 - "Mediastinal hematomas can be due to injury to other structures including the pulmonary artery, great vessels or mediastinal veins, or even fractures of vertebral bodies. Presence of a mediastinal hematoma should prompt a careful search for an aortic, pulmonary artery or great vessel injury. In the absence of an identified arterial injury the hematoma is likely venous. A preserved fat plane around the aorta or hematoma centered away from the aorta is less likely to be associated with aortic injury and more likely to be venous.”
Traumatic aortic injury: CT findings, mimics, and therapeutic options
Ethany L. Cullen et al.
Cardiovasc Diagn Ther 2014;4(3):238-244 - "The best way to distinguish a true aortic root injury from motion artifact is to repeat thoracic imaging with ECG gating; and echocardiography can be a reasonable alternative. The difference between a study done without and with ECG gating is illustrated in. In our institution all of the chest CT done as part of a trauma survey are acquired without ECG gating. Since the majority of TAIs are at the aortic isthmus, which is typically well seen on non-gated studies, we feel the additional radiation exposure and time required for setup and acquisition of an ECG gated study is not necessary for every patient.”
Traumatic aortic injury: CT findings, mimics, and therapeutic options
Ethany L. Cullen et al.
Cardiovasc Diagn Ther 2014;4(3):238-244 - “Blunt aortic injuries (BAI) represent the second leading cause of death from motor vehicle crashes accounting for 15% of all motor vehicle accident-associated deaths. Death occurs at the scene of the accident in 70–90% of the cases. According to historical case series, the majority of the patients with BAI (75%) who arrive to the hospi- tal alive are hemodynamically stable, but only 10% survive more than 6 h. Patients arriving to the hospital alive most frequently present with injury at the aortic isthmus where periadventitial tissue seems to provide some degree of protection against free rupture. The majority of patients with BAI have an associated closed head injury, multiple rib fractures, lung contusions, or orthopedic injuries.”
Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy
Rachel Elizabeth Payne et al.
European Journal of Trauma and Emergency Surgery (2019) 45:951–957 - “The SVS AI grading system is based on the following criteria: (grade I) intimal tear; (grade II) intramural hematoma; (grade III) pseudoaneurysm; (grade IV) rupture. Under this system, grade I-II are considered mild and grade III-IV are considered severe. In our investigation, we created criteria for radiographic severe injury and used this as a binary variable (severe versus the others) rather than creating a full grading system.”
Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy
Rachel Elizabeth Payne et al.
European Journal of Trauma and Emergency Surgery (2019) 45:951–957 - “Radiographically severe injuries were those meeting any of the following criteria: total/partial aortic transection, active contrast extravasation, or the association of 2 of more of the following: contained contrast extravasation > 10 mm, periaortic hematoma and/or mediastinal hematoma thicker than 10 mm, or significant left pleural effusion. We evaluated multiple inju- ries where a pseudoaneurysm was found in isolation, without significant associated hematoma or extravasation, which did not meet criteria for RSI. Thus, many injuries that would be graded III by the SVS system were not included in our RSI classification since they did not meet our selection criteria.”
Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy
Rachel Elizabeth Payne et al.
European Journal of Trauma and Emergency Surgery (2019) 45:951–957 - “Acute aortic injuries are not common in the setting of severe blunt trauma, but lead to significant morbidity and mortality. High- quality MDCT with 2D MPRs and 3D rendering are essential to identify aortic trauma and distinguish anatomic variants and other forms of aortic pathology from an acute injury. Misinterpretation of mimics of acute aortic injury can lead to unnecessary arteriography and thoracic surgery. Since most traumatic injuries occur in the distal arch, radiologists must be cognizant of the range of appearances of variants related to the ductus diverticulum. Cinematic rendering (CR) is a new 3D post-processing tool that provides even greater anatomic detail than traditional volume rendering. In this case series, CR is used to impart to radiologists a better understanding of various anatomic configurations that can be seen with a ductus diverticulum.”
MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury
Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
Emergency Radiology (2018) 25:209–213 - "Among these is the ductus diverticulum—a remnant of the ductus arteriosus that arises from the lesser curvature of the aortic arch, which can be mistaken for a traumatic aortic pseudoaneurysm, dissection, or incomplete rupture. The distal aortic arch, and in particular the undersurface, is the most common location for acute traumatic aortic injury. Differentiation of a ductus diverticulum from an aortic injury can be difficult, but it is of paramount importance in order to spare patients the morbidity of unnecessary thoracic surgery. This becomes more challenging in the setting of other thoracic traumatic injury, especially mediastinal hematoma, as demonstrated in this case report.”
MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury
Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
Emergency Radiology (2018) 25:209–213 - "Postprocessing with 2D multiplanar reconstructions and 3D rendering has become standard of care in CT angiography. One of the advantages of volume rendering over maximum intensity projection is the ability to convey 3D anatomic relationships. For complex anatomic configurations like the thoracic aorta and pulmonary arteries, the lighting model in cinematic rendering adds even greater anatomic detail, as demonstrated by these cases. The potential added value of cinematic rendering in accurately identifying and characterizing vascular pathology will require further study as this new 3D visualization methodology becomes more widely available.”
MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury
Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
Emergency Radiology (2018) 25:209–213 - “A number of artifacts can mimic a traumatic injury of the thoracic aorta. The classic example is that of the cardiac pulsation artifact, especially in the ascending aorta. If there is any doubt, CT angiography with ECG-gating or a transoesophageal echocardiogram will allow this pathology to be excluded in stable patient. Nonetheless, there remain a number of pitfalls that require particular attention.”
Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
F.Z. Mokranea et al.
Diagnostic and Interventional Imaging (2015) 96, 693—706 - “Nonetheless, there remain a number of pitfalls that require particular attention:
•pseudo ruptures: on lateral aortic imaging there is an accumulation of contrast material in a wall crevice, andthis finding varies in terms of whether or not it points to a pathology. It is usually a congenital abnormality, such as a dilation at the aortic insertion into an arterial canal, known as ductus diverticulum. Sometimes these images correspond to acquired conditions, such as aneurysms or simple or complicated plaques of atherosclerosis.”
Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
F.Z. Mokranea et al.
Diagnostic and Interventional Imaging (2015) 96, 693—706 - • mediastinal haematoma of venous origin: not all mediastinal bleeding corresponds to aortic injury. The literature describes trauma injuries to the great veins like the supe-rior vena cava. These injuries are rare but they can be life-threatening;
• mediastinal haematoma secondary to an extra-aortic injury. It is important to know how to detect abnormalitiesof the supra-aortic vessels, possibly using 3D reconstruct-ions. These dangerous lesions are a therapeutic challenge.They are often associated with aortic injuries although they can sometimes be isolated.
Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
F.Z. Mokranea et al.
Diagnostic and Interventional Imaging (2015) 96, 693—706
- “Lung contusion is a focal parenchymal injury caused by disruption of the capillaries of the alveolar walls and septa, and leakage of blood into the alveolar spaces and interstitium. It is the most common type of lung injury in blunt chest trauma with a reported prevalence of 17–70% . The main mechanism is compression and tearing of the lung parenchyma at the site of impact (it may also occur contralaterally “contre-coup”) against osseous structures, rib fractures or pre-existing pleural adhesions. Lung contusion occurs at the time of injury, but it may be undetectable on chest radiography for the first 6 h after trauma.”
CT imaging of blunt chest trauma Oikonomou A et al. Insights Imaging. 2011 Jun; 2(3): 281–295. - “The pooling of haemorrhage and oedema will blossom at 24 h, rendering the contusion radiographically more evident, although CT may readily reveal it from the initial imaging . The appearance of consolidation on chest radiography after the first 24 h should raise suspicion of other pathological conditions such as aspiration, pneumonia and fat embolism . Contusions appear as geographic, non-segmental areas of ground-glass or nodular opacities or consolidation on CT that do not respect the lobar boundaries and may manifest air bronchograms if the bronchioles are not filled with blood.”
CT imaging of blunt chest trauma Oikonomou A et al. Insights Imaging. 2011 Jun; 2(3): 281–295. - “Soft tissue haematomas may occur during direct compression trauma when rib fractures cause laceration of veins or arteries. Soft tissue haematoma may become life-threatening if the patient is under anticoagulant therapy. If it is arterial in origin, embolisation is indicated. Breast haematomas can be serious in direct impact or compression injuries.”
CT imaging of blunt chest trauma Oikonomou A et al. Insights Imaging. 2011 Jun; 2(3): 281–295. - “Thoracic injury overall is the third most common cause of trauma following injury to the head and extremities. Thoracic trauma has a high morbidity and mortality, accounting for approximately 25% of trauma-related deaths, second only to head trauma. More than 70% of cases of blunt thoracic trauma are due to motor vehicle collisions, with the remainder caused by falls or blows from blunt objects.”
CT imaging of blunt chest trauma Oikonomou A et al. Insights Imaging. 2011 Jun; 2(3): 281–295.
- Vascular Emergencies of the Chest Post Trauma
- Aortic rupture (complete and incomplete)
- Traumatic aortic dissection
- Aortic dissection and rupture
- Traumatic acute intramural hematoma
- Pseudoaneurysm
- Catheter related injuries
- Foreign body embolization - “ Multirow CT angiography is a fast, safe and noninvasive imaging technique. In combination with two and three dimensional postprocessing techniques, it often clarifies complex vascular and nonvascular anatomy.”
Vascular Emergencies of the Thorax after Blunt and Iatrogenic Trauma: Multidetector Row CT and Three Dimensional Imaging
Alkadhi H et al.
RadioGraphics 2004:24:1239-1255