Pulmonary embolism (PE) occurs when a blood clot lodges in the pulmonary arteries. It can be difficult to diagnose due to non-specific symptoms. Imaging plays a key role in the evaluation of suspected PE. Computed tomography pulmonary angiography (CTPA) has become the initial imaging test of choice since it can directly visualize thrombi and rule out other potential causes. It has high sensitivity and specificity. Ventilation-perfusion scintigraphy and pulmonary angiography are older modalities that remain useful in certain settings. New techniques like dual-energy CT may improve detection of subsegmental emboli. Right heart strain on CT suggests worse prognosis.
This document discusses pulmonary vasculature abnormalities including pulmonary artery hypertension, pulmonary edema, pulmonary embolism, and venous abnormalities. It provides definitions, classifications, risk factors, and radiographic findings for each condition. For pulmonary artery hypertension, the document describes the definition, etiology, classification systems, and findings on plain radiography, CT, and MRI. It also discusses pulmonary edema, pulmonary embolism, pulmonary arteriovenous malformations, pulmonary varices, and pulmonary venoocclusive disease.
This document discusses various developmental anomalies and airway diseases that can be evaluated using computed tomography (CT) of the chest. It covers topics such as tracheal bronchus, bronchial atresia, pulmonary sequestration, pulmonary arteriovenous malformation, scimitar syndrome, tracheal stenosis, saber sheath trachea, tracheobronchomegaly, and tracheobronchomalacia. For each condition, it discusses etiology, clinical features, and imaging findings visible on techniques such as CT, MRI, radiography, and angiography.
Thoracic Imaging in critically ill patientsGamal Agmy
Chest radiography remains the primary imaging modality for critically ill patients, however images are often limited quality due to patient movement and positioning challenges. Mistakes can occur in assessing conditions like pleural effusions or infiltrates. Routine daily chest x-rays are not recommended for ICU patients unless clinically indicated. Ultrasound is a useful bedside tool for evaluating the lungs, IVC, heart, and detecting pneumothorax. Computed tomography can also be used but requires transporting unstable patients.
This document discusses computed tomography (CT) imaging findings of various chest diseases, including pleural diseases, chest wall diseases, and mediastinal diseases. It describes how CT can be used to identify and characterize pleural effusions, pleural thickening, asbestos-related pleural disease, and tumors of the pleura. It also discusses chest wall abnormalities such as pectus excavatum, pectus carinatum, and Poland syndrome. Finally, it provides guidance on using CT findings to localize diseases within the mediastinum and differentiate various mediastinal abnormalities.
This document discusses imaging of chest trauma. It notes that injuries to the thorax are among the most common injuries seen in trauma patients. Various mechanisms of injury are described including blunt trauma, penetrating trauma, and compression injuries. Specific injuries discussed include rib fractures, flail chest, lung contusions, pneumothoraces, hemothoraces, and injuries to the heart, great vessels, spine and diaphragm. Imaging recommendations are provided for various scenarios, with chest x-ray as initial test but CT noted as more sensitive for detecting many injuries.
This document summarizes pulmonary embolism (PE) diagnosis. It states that over 650,000 PE cases are diagnosed annually in the US, with a mortality rate of 30% that can be reduced to 3-10% with treatment. Computed tomography angiography (CTA) has become widely used as the primary diagnostic method, though some patients cannot undergo CTA due to contrast allergy or renal failure. Ventilation/perfusion (V/Q) scanning remains important and has significantly lower radiation exposure than CTA, making it preferable for some patients. Both CTA and V/Q scanning have limitations and neither has proven clearly superior to the other for PE diagnosis.
Radiological Presentation of Pulmonary PathologyGamal Agmy
This document discusses various radiographic signs seen on chest x-rays and CT scans related to different types of lung collapse and cystic lung lesions. It describes signs such as the flat waist sign seen in left lower lobe collapse, the juxtaphrenic peak sign seen in upper lobe collapse, and the fallen lung sign seen with bronchial fractures. It also discusses cystic lung patterns seen in conditions like lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis, and lymphocytic interstitial pneumonia. Different characteristics of cysts such as their size, distribution and appearance on imaging are described for these various conditions.
This document discusses pulmonary vasculature abnormalities including pulmonary artery hypertension, pulmonary edema, pulmonary embolism, and venous abnormalities. It provides definitions, classifications, risk factors, and radiographic findings for each condition. For pulmonary artery hypertension, the document describes the definition, etiology, classification systems, and findings on plain radiography, CT, and MRI. It also discusses pulmonary edema, pulmonary embolism, pulmonary arteriovenous malformations, pulmonary varices, and pulmonary venoocclusive disease.
This document discusses various developmental anomalies and airway diseases that can be evaluated using computed tomography (CT) of the chest. It covers topics such as tracheal bronchus, bronchial atresia, pulmonary sequestration, pulmonary arteriovenous malformation, scimitar syndrome, tracheal stenosis, saber sheath trachea, tracheobronchomegaly, and tracheobronchomalacia. For each condition, it discusses etiology, clinical features, and imaging findings visible on techniques such as CT, MRI, radiography, and angiography.
Thoracic Imaging in critically ill patientsGamal Agmy
Chest radiography remains the primary imaging modality for critically ill patients, however images are often limited quality due to patient movement and positioning challenges. Mistakes can occur in assessing conditions like pleural effusions or infiltrates. Routine daily chest x-rays are not recommended for ICU patients unless clinically indicated. Ultrasound is a useful bedside tool for evaluating the lungs, IVC, heart, and detecting pneumothorax. Computed tomography can also be used but requires transporting unstable patients.
This document discusses computed tomography (CT) imaging findings of various chest diseases, including pleural diseases, chest wall diseases, and mediastinal diseases. It describes how CT can be used to identify and characterize pleural effusions, pleural thickening, asbestos-related pleural disease, and tumors of the pleura. It also discusses chest wall abnormalities such as pectus excavatum, pectus carinatum, and Poland syndrome. Finally, it provides guidance on using CT findings to localize diseases within the mediastinum and differentiate various mediastinal abnormalities.
This document discusses imaging of chest trauma. It notes that injuries to the thorax are among the most common injuries seen in trauma patients. Various mechanisms of injury are described including blunt trauma, penetrating trauma, and compression injuries. Specific injuries discussed include rib fractures, flail chest, lung contusions, pneumothoraces, hemothoraces, and injuries to the heart, great vessels, spine and diaphragm. Imaging recommendations are provided for various scenarios, with chest x-ray as initial test but CT noted as more sensitive for detecting many injuries.
This document summarizes pulmonary embolism (PE) diagnosis. It states that over 650,000 PE cases are diagnosed annually in the US, with a mortality rate of 30% that can be reduced to 3-10% with treatment. Computed tomography angiography (CTA) has become widely used as the primary diagnostic method, though some patients cannot undergo CTA due to contrast allergy or renal failure. Ventilation/perfusion (V/Q) scanning remains important and has significantly lower radiation exposure than CTA, making it preferable for some patients. Both CTA and V/Q scanning have limitations and neither has proven clearly superior to the other for PE diagnosis.
Radiological Presentation of Pulmonary PathologyGamal Agmy
This document discusses various radiographic signs seen on chest x-rays and CT scans related to different types of lung collapse and cystic lung lesions. It describes signs such as the flat waist sign seen in left lower lobe collapse, the juxtaphrenic peak sign seen in upper lobe collapse, and the fallen lung sign seen with bronchial fractures. It also discusses cystic lung patterns seen in conditions like lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis, and lymphocytic interstitial pneumonia. Different characteristics of cysts such as their size, distribution and appearance on imaging are described for these various conditions.
Multidetector computed tomography (MDCT) allows for the comprehensive examination of the chest with high sensitivity and specificity. It can detect pulmonary contusions and other thoracic injuries like rib fractures, hemothoraces, and pneumothoraces that may be missed on initial chest x-rays. MDCT is now the gold standard for diagnosing pulmonary contusions due to its ability to quantify the amount of injured lung and predict patient prognosis. The rapid acquisition speed of MDCT reduces motion artifacts compared to previous CT technologies.
1. The document discusses various types of pleural effusions seen on imaging. It describes how small effusions initially accumulate in the costophrenic angles and can be seen on lateral but not frontal views.
2. As effusions increase in size, they become visible on frontal views and spread upward in the thorax. Large effusions can obscure the entire hemithorax.
3. Effusions can have atypical distributions such as loculated collections or positions between the lung and diaphragm that mimic hemidiaphragm elevation. Loculated effusions are commonly seen in fissures.
Presentation1.pptx, radiological imaging of pulmonary embolism.Abdellah Nazeer
This document discusses pulmonary embolism (PE), which occurs when a blood clot or other substance blocks a pulmonary artery in the lungs. PE is commonly caused by deep vein thrombosis. The document outlines common symptoms of PE and risk factors. It then describes various radiological imaging techniques used to diagnose PE, including chest X-rays, CT scans, ultrasound, V/Q scans, pulmonary angiograms, and MRI. The document discusses diagnostic criteria for PE on CT imaging and provides examples of images showing acute and chronic PE. It also covers D-dimer testing and describes the appearance of massive, saddle, and bilateral PE on CT scans.
An Educational material showing Chest Imaging and describing NORMAL IMAGING-VOLUME LOSS-LOSS OF PARENCHYMA-ALVEOLAR PROCESSES-BRONCHIECTASIS
PLEURAL ABNORMALITIES
NODULES AND MASSES
This document provides an overview of imaging techniques used in the evaluation of thoracic trauma. It begins with an introduction to the epidemiology of thoracic injuries and the importance of rapid diagnosis. The initial assessment involves a primary and secondary survey with a focus on airway, breathing and circulation. The imaging survey typically begins with a portable chest x-ray to evaluate for pneumothorax, hemothorax and other injuries followed by an ultrasound to assess for pericardial effusion. Additional sections discuss specific injuries like flail chest, hemothorax and tension pneumothorax that may be seen on CXR. The role of CT in thoracic trauma evaluation is also reviewed.
This document summarizes the diagnostic criteria and causes of misdiagnosis for computed tomography angiography (CTA) of pulmonary embolism (PE). It outlines the diagnostic criteria for acute and chronic PE seen on CTA images, including signs such as intraluminal filling defects and vessel occlusion. It then discusses numerous technical, anatomic and pathological factors that can cause misdiagnosis of PE on CTA images, such as respiratory motion artifact, image noise, vascular bifurcations and lymph node enlargement. Patient-related, equipment and interpretation factors are all reviewed in detail to help reduce incorrect diagnosis.
Imaging in mediastinal masses by Dr. Milan SilwalMilan Silwal
This document provides an overview of imaging methods used to evaluate mediastinal pathologies. It discusses the relevant anatomy of the mediastinum and its divisions. Common imaging modalities like CT, MRI, ultrasound, and PET are described for assessing mediastinal masses and diffuse diseases. The document outlines an approach to characterizing mediastinal abnormalities by first localizing the mass within the mediastinum, then characterizing it with CT or MRI to determine benign vs malignant nature. Anterior, middle and posterior compartment masses have distinguishing features on imaging.
This document provides information on pleural lesions, including pleural effusions, hemothorax, empyema, and chylothorax. Key points include:
- Pleural effusions can be transudative or exudative based on protein and LDH levels, and can be caused by tumors, inflammation, cardiovascular issues, congenital defects, trauma or metabolic problems.
- Empyema is an infected pleural effusion that progresses through exudative, fibrinopurulent and fibrinous stages. It appears lenticular on x-ray and CT shows thickened, enhancing pleura.
- Chylothorax is the presence of chylous fluid in the ple
Radiological diagnostics of Respiratory systemEneutron
This document discusses various radiological diagnostic methods for examining the respiratory system, including direct visualization methods, radiographic methods, analytic methods, special contrast methods, functional methods, and others such as fluoroscopy, MRI, and ultrasound. It describes techniques such as bronchography and CT scans. Pathological findings are outlined, including signs of air-free opacity, clarification, and vascular changes. Syndromes of various pulmonary diseases are also detailed.
Pulmonary embolism is caused by a blockage in the pulmonary artery from substances traveling through the bloodstream, most commonly from deep vein thrombosis. It is a common and potentially lethal condition. Diagnosis is challenging as symptoms are non-specific and it is often overlooked or missed. Imaging tests like CT pulmonary angiography, ventilation-perfusion scans, and pulmonary angiography are used to diagnose pulmonary embolism, while ultrasound of the legs can identify deep vein thrombosis, a major risk factor. Prompt diagnosis and treatment are important to prevent mortality from this potentially serious condition.
This document discusses pulmonary tumors, including:
1. It categorizes pulmonary tumors into malignant tumors, low-grade malignancies, and benign tumors. The main malignant tumors discussed are bronchogenic carcinoma, bronchoalveolar carcinoma, lymphoma, metastases, and rare sarcomas.
2. Bronchogenic carcinoma is further broken down by classification, risk factors, location, and radiographic findings. The classifications include adenocarcinoma, squamous cell carcinoma, small cell carcinoma, large cell carcinoma, and adenosquamous tumor. Cavitation and air bronchograms are among the key radiographic findings.
3. Pancoast tumors, a type of superior sulcus tumor, are defined as tumors located
This document discusses pulmonary thromboembolism (PE), which occurs when a blood clot blocks the pulmonary artery or its branches in the lungs. PE is usually caused by deep vein thrombosis, where a clot breaks off and travels to the lungs. Symptoms include dyspnea, chest pain, and coughing. Risk factors include prolonged immobilization, recent surgery or trauma, oral contraceptive use, pregnancy, and inherited or acquired hypercoagulable states. Diagnosis involves chest x-ray, ventilation-perfusion scanning, and pulmonary angiography to detect clots in the pulmonary arteries.
This document discusses the evaluation, staging, surgical treatment options, complications, and prognosis for lung cancer. Key points include:
- Evaluation involves imaging like CT scans, biopsies, and pulmonary function tests. Surgery is indicated for early stage tumors.
- Surgical options include lobectomy, pneumonectomy, wedge resection or segmental resection depending on tumor size and location.
- Complications can include air leaks, infection, hemorrhage or formation of a bronchopleural fistula. Outcomes depend on cancer cell type and stage, with earlier stage having higher 5-year survival rates.
This document discusses pulmonary sequestration, including its pathogenesis, types, clinical presentation, evaluation, and treatment. Pulmonary sequestration is a rare congenital abnormality where non-functioning lung tissue receives its blood supply from systemic arteries rather than pulmonary arteries. It is classified as either intralobar, located within a normal lung lobe, or extralobar, located outside the normal lung with its own pleura. Evaluation involves imaging like chest X-ray, CT, MRI, and nuclear scans to identify the abnormal systemic arterial supply.
Post operative chest by Dr. Sundar SuwalMilan Silwal
This document provides an overview of the expected postoperative chest appearances and potential complications following various thoracic surgeries including thoracotomy, pneumonectomy, lobectomy, segmentectomy, cardiac surgery, and general surgeries with thoracic complications. It describes the typical radiographic findings in the immediate postoperative period and as healing progresses over weeks and months. Complications discussed include pulmonary edema, bronchopleural fistula, empyema, lobar torsion, and gossypiboma among others. Accurate identification of postoperative changes and complications is important for timely diagnosis and management.
There are 4 main types of CT scans described in the document: standard CT, high resolution CT, low dose CT, and CT angiography.
Standard CT uses thicker slices (3-10mm) to quickly scan a large volume and cover the full lung, sometimes with contrast. High resolution CT uses narrower beam collimation (1-1.3mm) and further slice spacing (10mm) to provide high definition images of lung structures for diagnosing lung diseases. Low dose CT aims to maintain diagnostic functionality while lowering radiation dose, and is used for cancer screening and follow up of lung conditions. CT angiography involves injecting contrast into the bloodstream to visualize arteries like the pulmonary arteries, and is used
This document discusses the CT anatomy and imaging of the mediastinum. It outlines 6 objectives, including describing the CT anatomy of the mediastinum, pneumomediastinum, mediastinal lymphadenopathy, radiological description of mediastinal compartments, differential diagnosis of mediastinal disease, and interventional supply. It then provides detailed descriptions and images of the different mediastinal compartments and lymph node stations.
Chest trauma can involve injuries to multiple structures in the chest cavity. Common injuries include pneumothorax, hemothorax, rib fractures, lung contusions and lacerations. On chest x-ray, a pneumothorax appears as a thin white line along the edge of the lung with no lung markings extending past it. A tension pneumothorax causes mediastinal shift away from the affected side. CT is useful for evaluating lung injuries like contusions, which appear as non-segmental areas of opacity, and lacerations, which may form pneumatoceles. Proper diagnosis requires understanding the mechanisms and radiographic appearances of various chest trauma injuries.
This document summarizes pulmonary embolism (PE), including its epidemiology, risk factors, pathophysiology, clinical features, diagnostic testing, and treatment. PE is the second most common cause of unexpected death, with risk factors including recent surgery, trauma, cancer, and inherited or acquired thrombophilias. Diagnosis involves assessing clinical probability then confirming with D-dimer, imaging like CT pulmonary angiogram, or lung scintigraphy. For acute PE, initial treatment is heparin or fondaparinux followed by long-term oral anticoagulation to prevent recurrence. New oral anticoagulants targeting factor Xa provide alternatives to warfarin.
This document discusses pulmonary thromboembolism (PE), including:
- The anatomy of the pulmonary vasculature and definitions of acute PE.
- Risk factors for PE include inherited or acquired hypercoagulability states.
- Presentation is often nonspecific but may include dyspnea, chest pain, or syncope. Diagnosis is made using D-dimer, CTA, or V/Q scan.
- CTA directly visualizes intraluminal thrombi and allows assessment of right heart strain. Chronic thromboembolism involves organized thrombi causing pulmonary hypertension.
Multidetector computed tomography (MDCT) allows for the comprehensive examination of the chest with high sensitivity and specificity. It can detect pulmonary contusions and other thoracic injuries like rib fractures, hemothoraces, and pneumothoraces that may be missed on initial chest x-rays. MDCT is now the gold standard for diagnosing pulmonary contusions due to its ability to quantify the amount of injured lung and predict patient prognosis. The rapid acquisition speed of MDCT reduces motion artifacts compared to previous CT technologies.
1. The document discusses various types of pleural effusions seen on imaging. It describes how small effusions initially accumulate in the costophrenic angles and can be seen on lateral but not frontal views.
2. As effusions increase in size, they become visible on frontal views and spread upward in the thorax. Large effusions can obscure the entire hemithorax.
3. Effusions can have atypical distributions such as loculated collections or positions between the lung and diaphragm that mimic hemidiaphragm elevation. Loculated effusions are commonly seen in fissures.
Presentation1.pptx, radiological imaging of pulmonary embolism.Abdellah Nazeer
This document discusses pulmonary embolism (PE), which occurs when a blood clot or other substance blocks a pulmonary artery in the lungs. PE is commonly caused by deep vein thrombosis. The document outlines common symptoms of PE and risk factors. It then describes various radiological imaging techniques used to diagnose PE, including chest X-rays, CT scans, ultrasound, V/Q scans, pulmonary angiograms, and MRI. The document discusses diagnostic criteria for PE on CT imaging and provides examples of images showing acute and chronic PE. It also covers D-dimer testing and describes the appearance of massive, saddle, and bilateral PE on CT scans.
An Educational material showing Chest Imaging and describing NORMAL IMAGING-VOLUME LOSS-LOSS OF PARENCHYMA-ALVEOLAR PROCESSES-BRONCHIECTASIS
PLEURAL ABNORMALITIES
NODULES AND MASSES
This document provides an overview of imaging techniques used in the evaluation of thoracic trauma. It begins with an introduction to the epidemiology of thoracic injuries and the importance of rapid diagnosis. The initial assessment involves a primary and secondary survey with a focus on airway, breathing and circulation. The imaging survey typically begins with a portable chest x-ray to evaluate for pneumothorax, hemothorax and other injuries followed by an ultrasound to assess for pericardial effusion. Additional sections discuss specific injuries like flail chest, hemothorax and tension pneumothorax that may be seen on CXR. The role of CT in thoracic trauma evaluation is also reviewed.
This document summarizes the diagnostic criteria and causes of misdiagnosis for computed tomography angiography (CTA) of pulmonary embolism (PE). It outlines the diagnostic criteria for acute and chronic PE seen on CTA images, including signs such as intraluminal filling defects and vessel occlusion. It then discusses numerous technical, anatomic and pathological factors that can cause misdiagnosis of PE on CTA images, such as respiratory motion artifact, image noise, vascular bifurcations and lymph node enlargement. Patient-related, equipment and interpretation factors are all reviewed in detail to help reduce incorrect diagnosis.
Imaging in mediastinal masses by Dr. Milan SilwalMilan Silwal
This document provides an overview of imaging methods used to evaluate mediastinal pathologies. It discusses the relevant anatomy of the mediastinum and its divisions. Common imaging modalities like CT, MRI, ultrasound, and PET are described for assessing mediastinal masses and diffuse diseases. The document outlines an approach to characterizing mediastinal abnormalities by first localizing the mass within the mediastinum, then characterizing it with CT or MRI to determine benign vs malignant nature. Anterior, middle and posterior compartment masses have distinguishing features on imaging.
This document provides information on pleural lesions, including pleural effusions, hemothorax, empyema, and chylothorax. Key points include:
- Pleural effusions can be transudative or exudative based on protein and LDH levels, and can be caused by tumors, inflammation, cardiovascular issues, congenital defects, trauma or metabolic problems.
- Empyema is an infected pleural effusion that progresses through exudative, fibrinopurulent and fibrinous stages. It appears lenticular on x-ray and CT shows thickened, enhancing pleura.
- Chylothorax is the presence of chylous fluid in the ple
Radiological diagnostics of Respiratory systemEneutron
This document discusses various radiological diagnostic methods for examining the respiratory system, including direct visualization methods, radiographic methods, analytic methods, special contrast methods, functional methods, and others such as fluoroscopy, MRI, and ultrasound. It describes techniques such as bronchography and CT scans. Pathological findings are outlined, including signs of air-free opacity, clarification, and vascular changes. Syndromes of various pulmonary diseases are also detailed.
Pulmonary embolism is caused by a blockage in the pulmonary artery from substances traveling through the bloodstream, most commonly from deep vein thrombosis. It is a common and potentially lethal condition. Diagnosis is challenging as symptoms are non-specific and it is often overlooked or missed. Imaging tests like CT pulmonary angiography, ventilation-perfusion scans, and pulmonary angiography are used to diagnose pulmonary embolism, while ultrasound of the legs can identify deep vein thrombosis, a major risk factor. Prompt diagnosis and treatment are important to prevent mortality from this potentially serious condition.
This document discusses pulmonary tumors, including:
1. It categorizes pulmonary tumors into malignant tumors, low-grade malignancies, and benign tumors. The main malignant tumors discussed are bronchogenic carcinoma, bronchoalveolar carcinoma, lymphoma, metastases, and rare sarcomas.
2. Bronchogenic carcinoma is further broken down by classification, risk factors, location, and radiographic findings. The classifications include adenocarcinoma, squamous cell carcinoma, small cell carcinoma, large cell carcinoma, and adenosquamous tumor. Cavitation and air bronchograms are among the key radiographic findings.
3. Pancoast tumors, a type of superior sulcus tumor, are defined as tumors located
This document discusses pulmonary thromboembolism (PE), which occurs when a blood clot blocks the pulmonary artery or its branches in the lungs. PE is usually caused by deep vein thrombosis, where a clot breaks off and travels to the lungs. Symptoms include dyspnea, chest pain, and coughing. Risk factors include prolonged immobilization, recent surgery or trauma, oral contraceptive use, pregnancy, and inherited or acquired hypercoagulable states. Diagnosis involves chest x-ray, ventilation-perfusion scanning, and pulmonary angiography to detect clots in the pulmonary arteries.
This document discusses the evaluation, staging, surgical treatment options, complications, and prognosis for lung cancer. Key points include:
- Evaluation involves imaging like CT scans, biopsies, and pulmonary function tests. Surgery is indicated for early stage tumors.
- Surgical options include lobectomy, pneumonectomy, wedge resection or segmental resection depending on tumor size and location.
- Complications can include air leaks, infection, hemorrhage or formation of a bronchopleural fistula. Outcomes depend on cancer cell type and stage, with earlier stage having higher 5-year survival rates.
This document discusses pulmonary sequestration, including its pathogenesis, types, clinical presentation, evaluation, and treatment. Pulmonary sequestration is a rare congenital abnormality where non-functioning lung tissue receives its blood supply from systemic arteries rather than pulmonary arteries. It is classified as either intralobar, located within a normal lung lobe, or extralobar, located outside the normal lung with its own pleura. Evaluation involves imaging like chest X-ray, CT, MRI, and nuclear scans to identify the abnormal systemic arterial supply.
Post operative chest by Dr. Sundar SuwalMilan Silwal
This document provides an overview of the expected postoperative chest appearances and potential complications following various thoracic surgeries including thoracotomy, pneumonectomy, lobectomy, segmentectomy, cardiac surgery, and general surgeries with thoracic complications. It describes the typical radiographic findings in the immediate postoperative period and as healing progresses over weeks and months. Complications discussed include pulmonary edema, bronchopleural fistula, empyema, lobar torsion, and gossypiboma among others. Accurate identification of postoperative changes and complications is important for timely diagnosis and management.
There are 4 main types of CT scans described in the document: standard CT, high resolution CT, low dose CT, and CT angiography.
Standard CT uses thicker slices (3-10mm) to quickly scan a large volume and cover the full lung, sometimes with contrast. High resolution CT uses narrower beam collimation (1-1.3mm) and further slice spacing (10mm) to provide high definition images of lung structures for diagnosing lung diseases. Low dose CT aims to maintain diagnostic functionality while lowering radiation dose, and is used for cancer screening and follow up of lung conditions. CT angiography involves injecting contrast into the bloodstream to visualize arteries like the pulmonary arteries, and is used
This document discusses the CT anatomy and imaging of the mediastinum. It outlines 6 objectives, including describing the CT anatomy of the mediastinum, pneumomediastinum, mediastinal lymphadenopathy, radiological description of mediastinal compartments, differential diagnosis of mediastinal disease, and interventional supply. It then provides detailed descriptions and images of the different mediastinal compartments and lymph node stations.
Chest trauma can involve injuries to multiple structures in the chest cavity. Common injuries include pneumothorax, hemothorax, rib fractures, lung contusions and lacerations. On chest x-ray, a pneumothorax appears as a thin white line along the edge of the lung with no lung markings extending past it. A tension pneumothorax causes mediastinal shift away from the affected side. CT is useful for evaluating lung injuries like contusions, which appear as non-segmental areas of opacity, and lacerations, which may form pneumatoceles. Proper diagnosis requires understanding the mechanisms and radiographic appearances of various chest trauma injuries.
This document summarizes pulmonary embolism (PE), including its epidemiology, risk factors, pathophysiology, clinical features, diagnostic testing, and treatment. PE is the second most common cause of unexpected death, with risk factors including recent surgery, trauma, cancer, and inherited or acquired thrombophilias. Diagnosis involves assessing clinical probability then confirming with D-dimer, imaging like CT pulmonary angiogram, or lung scintigraphy. For acute PE, initial treatment is heparin or fondaparinux followed by long-term oral anticoagulation to prevent recurrence. New oral anticoagulants targeting factor Xa provide alternatives to warfarin.
This document discusses pulmonary thromboembolism (PE), including:
- The anatomy of the pulmonary vasculature and definitions of acute PE.
- Risk factors for PE include inherited or acquired hypercoagulability states.
- Presentation is often nonspecific but may include dyspnea, chest pain, or syncope. Diagnosis is made using D-dimer, CTA, or V/Q scan.
- CTA directly visualizes intraluminal thrombi and allows assessment of right heart strain. Chronic thromboembolism involves organized thrombi causing pulmonary hypertension.
This document provides information on pulmonary embolism (PE). It defines PE as thrombosis originating in the venous system and embolizing to the pulmonary arterial circulation. PE contributes to 5-10% of hospital deaths. Risk factors include prolonged immobility, recent surgery or trauma, and inherited or acquired thrombophilias. Symptoms include dyspnea, chest pain, coughing up blood. Diagnostic tests include D-dimer, CT pulmonary angiogram, ventilation-perfusion scan, echocardiogram. Treatment involves anticoagulation with heparin or novel oral anticoagulants to prevent early death and recurrence, as well as thrombolysis for massive PE to restore pulmonary blood flow.
This document discusses hemostasis, thrombosis, pulmonary embolism, risk factors, diagnosis, and treatment of venous thromboembolism. It defines key terms like thrombus, embolus, and saddle pulmonary embolism. Diagnostic tests covered include D-dimer, ventilation-perfusion scan, and CTA. Treatment involves anticoagulants like heparin, LMWH, factor Xa inhibitors, and thrombolytic therapy. Long-term management uses warfarin or novel oral anticoagulants. Prophylaxis is also discussed.
Pulmonary embolism is a blockage of the pulmonary artery or its branches by material that has traveled from elsewhere in the body through the bloodstream. It is most commonly caused by deep vein thrombosis in the legs. Symptoms include dyspnea, chest pain, and cough. Risk factors include prolonged bed rest, cancer, oral contraceptives, and recent surgery or trauma. Diagnosis involves evaluating clinical probability and testing such as D-dimer, CT pulmonary angiography, ventilation-perfusion scanning, and pulmonary angiography. Treatment focuses on anticoagulation to prevent further clots.
emergency echo in critically ill patients.pptShivani Rao
Emergency echocardiography provides rapid assessment of cardiac function and physiology in critically ill patients with shock. A goal-directed echocardiogram should evaluate for pericardial effusion, left ventricular contractility, and right ventricular dilation. Key findings include cardiac tamponade, pulmonary embolism, and acute pump failure. Echocardiography can also identify pneumothorax, assess volume status, and rule out aortic dissection or DVT as potential causes of shock. It is a valuable tool for point-of-care decision making in critically ill patients.
A V/Q scan evaluates ventilation and perfusion of the lungs to diagnose pulmonary embolism (PE). It involves inhaling a radioactive gas to assess ventilation and receiving an IV injection of radioactive albumin to assess perfusion. Mismatched defects indicate PE while matched defects can indicate lung disease. The PIOPED study established criteria for classifying scans as high, intermediate, or low probability of PE. A normal scan makes PE unlikely while a high probability scan makes PE very likely. Other tests for PE include CT pulmonary angiogram, pulmonary angiogram, and chest x-ray.
This document summarizes CT findings that are useful for diagnosing chronic pulmonary thromboembolism (CPTE). It describes risk factors, clinical manifestations, and CT features of CPTE including vascular signs like pulmonary artery obstruction and dilation, parenchymal signs like scarring and mosaic perfusion patterns, and signs of pulmonary hypertension. Differential diagnoses including idiopathic pulmonary hypertension and acute PE are also discussed. CT is important for identifying treatable CPTE in patients with unexplained pulmonary hypertension.
PowerPoint presentation about pulmonary embolism -- Teaching at Zagazig university cardiology department ,
Egypt in 2013 by Islam Ghanem , assistant lecturer of cardiology
Deep vein thrombosis (DVT) and pulmonary embolism (PE), collectively known as venous thromboembolism (VTE), represent a major global health problem. VTE has significant morbidity and mortality but is also potentially treatable. The incidence of VTE is increasing due to factors like population aging and higher rates of comorbidities. Risk factors for VTE include hypercoagulability, stasis, vascular injury, cancer, immobilization, and surgery. Diagnosis involves assessment of clinical probability with tools like the Wells criteria and D-dimer testing. Imaging options include ultrasound, CT, ventilation-perfusion scanning, and pulmonary angiography. Treatment involves anticoagulation with drugs like heparin or
Lungs Cancer etiology sign symtom causes.pptxShaheerShakeel1
Lung cancer types vary by location. Squamous cell carcinoma is most common in the UK while adenocarcinoma is most common in the USA. Squamous cell carcinoma is typically central and can cause clubbing, hypercalcemia, and hypertrophic pulmonary osteoarthropathy. Adenocarcinoma is typically peripheral and may cause gynecomastia. Small cell lung cancer is very aggressive and often metastasizes early. It can cause paraneoplastic syndromes like SIADH, Cushing's syndrome, and Lambert-Eaton syndrome. Diagnosis involves imaging, biopsy, and tumor markers. Treatment depends on cancer type and stage but may include surgery, chemotherapy, and radiation therapy.
The document discusses hemoptysis, defined as bleeding from the lungs or bronchial tubes. It describes the dual arterial blood supply to the lungs from the pulmonary and bronchial arteries. Conditions that reduce pulmonary arterial flow can increase bronchial artery contribution, making those vessels prone to rupture and bleeding. A comprehensive evaluation of hemoptysis includes history, physical exam, labs, chest imaging including radiography and CT, and bronchoscopy. CT is particularly useful for evaluating underlying lung abnormalities and identifying abnormal bronchial vessels to guide treatment.
Pulmonary Embolism- Diagnosis by Dr.Tinku JosephDr.Tinku Joseph
This document discusses diagnostic tests for pulmonary embolism (PE). It describes various imaging studies including chest x-rays, V/Q scans, CT scans, pulmonary angiograms, and echocardiograms. It also discusses laboratory tests like D-dimer, troponin, and BNP levels. CT pulmonary angiography is becoming the initial test of choice due to its speed and ability to directly visualize PEs. V/Q scans remain useful in pregnant patients due to their lower radiation exposure compared to CT scans. No single test is perfect, so a combination of clinical assessment, imaging, and lab tests is usually needed to diagnose PE.
Pulmonary and venous thromboembolism.pptxNidhiBhutada5
This document discusses venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE). It covers the risk factors, pathophysiology, classification, clinical presentation, diagnostic modalities including imaging and labs, and treatment including anticoagulation options for VTE. The standard treatment is anticoagulant therapy to prevent further clot formation and extension. Parenteral anticoagulants such as heparin are initially used and then transitioned to oral anticoagulants such as warfarin or newer oral agents.
This document discusses differentials and radiological signs of conditions presenting with a unilateral hypertransradiant hemithorax. It provides two mnemonics, SAFE POEM and CRAWLS, listing potential causes such as rotation, pneumothorax, emphysema, bullous lung disease, Swyer-James syndrome, pulmonary embolism, and abnormalities of the chest wall or contralateral lung. For each condition, the document describes associated radiographic findings and example images. It aims to educate radiologists on evaluating and differentially diagnosing this common pediatric chest x-ray finding.
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2. Introduction
• Pulmonary thromboembolism (PTE) is a common clinical entity that
results in morbidity and mortality in a large number of patients.
• Because of same signs and symptoms with a large number of
diseases & nonspecific risk factors, the diagnosis continues to be a
great clinical challenge.
3. Pulmonary Thromboembolic Disease
• Pulmonary embolus lodges within branch pulmonary arteries
• usually arise from pelvic or lower limb vein
• Saddle’ embolus
• a thrombus lodged at the main pulmonary arterial bifurcation
• Pulmonary infarction
• relatively rare as there is a second ‘systemic’ arterial supply to the
lungs from the bronchial arteries
• Infarction therefore requires compromise of both arterial supplies
4. • Diagnosis of PTE is based on the following:
1) Clinical pre-test probability
2) D-dimer level
3) Imaging findings
6. Risk factors for PTE
• Advance ages
• Hypercoagulable state
• Orthopaedic surgery
• Pregnancy
• Malignant disease
• Prolong immobilization
• High oestrogen level
7. D-dimers
• breakdown product of crosslinked fibrin
• a measure of fibrinolytic activity
• ng/ml (<500)
• highly sensitive but non-specific test with a high false-positive rate
but a very high negative predictive value
• false-negative tests can occur (particularly with subsegmental emboli)
8. CLINICAL PRESENTATION
• Dyspnoea
• Chest pain (which may be pleuritic)
• Cough
• Haemoptysis
• Hypotension
• Tachycardia
• Pulmonary oedema (due to left ventricular failure precipitated by a
large PE)
• ECG changes are non-specific and only seen in patients with a severe
embolism: right bundle branch block right axis deviation and
ventricular hypertrophy
12. IMAGING EVALUATION OF PATIENTS
WITH
SUSPECTED PTE
1) Conventional chest X-ray
2) Pulmonary angiography
3) Ventilation-perfusion lung scintigraphy
4) Computed tomography pulmonary angiography (CTPA)
5) Dual-energy CT (DECT)
6) Magnetic resonance imaging (MRI) of the chest
7) Ultrasonography
13. • Usually not useful in diagnosis of PE
• Useful in excluding other cause of acute chest pain (pneumonia, pul.
oedema or pneumothorax)
Conventional chest X-ray
14. Most common signs (without infarction):
• Regional oligemia Westermark sign (hypovolemia in the region of the lung
irrigated by the occluded vessel)
(Localized reduction in the peripheral blood flow, with or without
distension of the proximal vessels)
• Peripheral airspace opacification: this represents pulmonary haemorrhage
• Linear atelectasis: ischaemic injury to type II pneumocytes leads to
surfactant deficiency
• Pleural effusions: often small
• Central pulmonary arterial enlargement (Fleischner sign) : this is secondary
to chronic repeated embolic disease
15. Signs associated with infarction:
• Hampton’s hump:
• a pleural based, wedge-shaped opacity usually seen within the lateral or posterior
costophrenic sulcus
• the apex of the triangle points toward the occluded feeding vessel with its base
against the pleural surface, rarely contains air bronchograms
• Consolidation
• may be multifocal, predominantly lower lobes
• can be seen from 12 h to several days post embolism
• Cavitation: secondary infection at the infarction site or following a septic
embolus
• Haemorrhagic pleural effusions: this is seen in 50% of patients
• Serial CXRs:
• rapid resolution of any parenchymal changes is associated with a non-infarcting
• PE – infarction normally heals with scarring and localized pleural thickening
16. Frontal chest radiograph in a 55-year-old male
shows a wedge-shaped opacity in the periphery of
the right lateral lung (red arrows) concerning for
infarction, dubbed a “Hampton hump”
CTPA shows a filling defect
within an enlarged right
lower lobe lateral segmental
pulmonary artery consistent
with occlusive thrombus
17. Pulmonary thromboembolism.
(A) CXR demonstrating a moderate right pleural effusion on the day of symptom onset.
(B) CT taken 2 days after symptom onset reveals a filling defect (representing thrombus) in the right
lower lobe pulmonary artery.
(C) Further CXR taken 10 days after (A) with the patient on anticoagulant therapy reveals resolution of
the previous effusion. As a sequelae, a thin band of atelectasis is seen in the right lower zone.*
18. Causes of Pulmonary arterial hypertension
• Chronic lung disease
• Pulmonary embolic disease
• Pulmonary venous hypertension
• Cardiac shunts (left to right and bidirectional)
• Pulmonary arteritides
19. CXR
• Cardiac enlargement (right atrial and ventricular enlargement)
• central pulmonary arterial enlargement
• ‘Peripheral pruning’: tapering of the peripheral arterial vessels beyond the
segmental level
CT
• A smoothly marginated hilar arterial outline (cf. a lobulated border with
lymphadenopathy)
• Pulmonary arterial calcification (due to atheroma) can be seen with chronic
disease
• A transverse diameter of the mid-right descending pulmonary artery >
17mm
• The diameter of the main pulmonary artery is greater than the adjacent
ascending aorta
20. Pulmonary Angiography
• Invasive diagnostic method
• Intravenous catheter is introduced into the proximal pulmonary artery and
the contrast medium is injected rapidly.
• High spatial resolution, direct evaluation of the pulmonary arterial tree
• Although pulmonary angiography is considered the gold standard method,
it can lead to complications, mainly anaphylaxis, contrast-induced
nephrotoxicity, cardiac events, and pulmonary complications
• Now used only when a concomitant endovascular treatment is planned
• Findings:
• occlusion with abrupt cut-off
• filling defects, slow flow, and
• regional hypo-perfusion
21.
22. Large right upper lobe filling defect consistent with acute PE
(arrow).
Also noted are areas of decreased perfusion within the
peripheral upper and lower lobes consistent with sub segmental
emboli.
23. Ventilation-perfusion lung
scintigraphy
• Although CTPA is the current gold standard, VQ scan is preferred,
particularly renal failure, contrast material allergies, young females, and
patients who cannot fit into the CT scanner.
• VQ scan has 50-fold lower radiation dose to the breast (0.28–0.9 vs. 50–80
mSv in 64 slice CT) , which makes it useful in young females, including
those who are pregnant.
• Ventilation agents
• aerosolized technetium-99m (Tc-99m) labeled agents [diethylene-
triamine-penta-acetic acid (DTPA), sulfur colloid, and ultrafine carbon
suspensions] and
• radioactive noble gases [Krypton-81m and Xenon-133
• Perfusion portion is performed following the intravenous injection of
200,000–700,000 particles of Tc-99m labeled macro-aggregated albumin
(MAA).
24. 81mKr
• optimal imaging agent
• emit high energy photons (190keV) & allows the ventilation images to
be obtained after the perfusion images allowing matching of both
image sets without moving the patient
• short half-life (13 s) it can be continuously administered (including
during perfusion imaging) although it means that no washout images
are possible
• Disadvantages:
• decreased resolution due to collimator penetration by the high-
energy photons
• it is expensive
25. 133Xe
• cheaper than 81mKr
• it is a less optimal imaging agent owing to its longer half-life (5.3 days)
and low photon energies (80keV)
• ventilation studies need to be performed prior to any perfusion
studies (thus preventing Compton scatter from the 99mTc into the
lower 133Xe photopeak)
• Single breath inhalation image: a cold spot is abnormal
• Equilibirum phase: tracer activity corresponds to aerated lung
• Washout phase: tracer retention corresponds to areas of air trapping
(e.g. COPD)
26. • Multiple planar images are obtained in upright position.
• Ventilation scans can be performed before or after the perfusion
scan.
• If perfusion scan is performed first and it is normal, then the
ventilation scan can be avoided, particularly in pregnant patients
• A peripheral wedge-shaped perfusion defect in a lobar, segmental, or
sub-segmental distribution without a corresponding ventilation
defect (i.e., a mismatched defect) raises the concern for the presence
of PE.
27. • Identifying ventilation in regions without perfusion at a location distal
to obstructing emboli is suggestive of PTE.
• Probability of embolism is classified as follows:
• High
• Intermediate
• Low
• Very low or
• Non-existent
• High probability confirm the diagnosis of PTE
• very low or non-existent probability allow the diagnosis to be
excluded.
28. • Anatomical data obtained with single-photon emission CT (SPECT)/CT
can be associated with the functional data obtained with scintigraphy.
• SPECT/CT has a high (99%) accuracy for the diagnosis, with a
sensitivity of 97–100% and a specificity of 83–100%
31. Normal V/Q study
Ventilation [v] images on top row and perfusion [p] images beneath.
No defects are seen in either series.
32. Matched defects – multiple foci of nontracer uptake seen in ventilation and
perfusion series. Images reveals that the defects are well matched for position on
both series.
33.
34. Perfusion defect (wedge-shaped peripherally) seen on perfusion imaging
which is not replicated on ventilation imaging.
This suggests a high probability for the presence of pulmonary embolus.*
38. Case 3 : middle aged female was referred with shortness of breath
39. CT Pulmonary Angiography (CTPA)
• CTPA is the imaging modality of choice for the workup of patients
with suspected acute PE
• high sensitivity and specificity, readily available, minimally invasive,
and fast with scan duration, cost-effective
• sensitive method of detecting main, lobar and segmental pulmonary
arterial emboli
• reliably detect emboli in up to 4th-order vessels (which are 7mm in
diameter)
40. CT windows for PE
• Lung window - width/level of 1500/600 HU
• Mediastinal window - width/level of 400/40 HU
• Pulmonary embolism window - width/level of 700/100 HU
41. Advantages
• Direct visualization of thrombus
• Can reveal other etiologies of chest pain and shortness of breath
(musculoskeletal injuries, pericardial abnormalities, pneumonia,
vascular pathologies, and even coronary artery disease)
Limitation
• not be suitable for patients with a low glomerular filtration rate (GFR)
42. Diagnostic criteria for acute PTE
• Arterial occlusion with filling defects throughout the lumen
• Diameter of occluded artery - increased in comparison with the
adjacent vessels
• Partial contrast filling defect:
• “polo mint” sign in images perpendicular to the long axis of the vessel
• “tram-track” sign in images acquired along that axis
• Pulmonary infarct
• wedge-shaped, peripheral opacity commonly with a “reverse-halo”
appearance consisting of central ground glass and a rim of consolidation
• Pleural effusions can also be seen with acute PE
43. Diagnostic criteria for chronic PTE
• intraluminal webs, calcification, thrombus recanalization, and filling defects
adherent to the wall that form obtuse angles and concave surfaces.
• vessels are typically smaller than normal, exhibit abnormal tapering, and
may show complete cut-off of the segmental vessel
• Parenchymal changes (mosaic perfusion, band-like opacities, and bronchial
dilation in abnormal areas)
• arterial recanalization; and the presence of a “web” within a contrast-filled
artery.
• Infarction: a peripheral wedge-shaped region of consolidation (analogous
to a Hampton’s hump on CXR) this is only a specific sign if the vessel can be
traced to the apex of the wedge
• Parameters for estimating the severity of PE and risk-stratification (right
heart strain, clot burden and lung perfusion)
44. • Features of right heart strain
• increased right ventricle (RV)/left ventricular (LV) ratio (>1 in axial
plane, >0.9 in 4-chamber reconstruction),
• flattening of interventricular septum and
• reflux of contrast material into the IVC and hepatic veins.
• RV/LV ratio >1.1 has been associated with increased risk of death
within 30 days. Four-chamber RV/LV ratio >0.9
45. Acute PTE in a 62-year-old female patient. CT slices, in axial and coronal
views (A and B, respectively), showing an extensive irregular filling defect in
the right and left pulmonary arteries, extending to its segmental branches.
46. Chronic PTE in an 86-year-old female patient with a history of breast
cancer. Axial CT scan showing a filling defect with obtuse margins in
the right pulmonary artery, with patent flow in the distal bed.
47. Correlation between a coronal CT slice (A) and a T2-weighted fast-spin-echo
coronal MRI sequence (B) showing a filling defect at the pulmonary artery
bifurcation.
48. CTPA demonstrating multiple bilateral
pulmonary emboli.
CTPA demonstrating a large filling
defect (thrombus) within the right main
pulmonary artery
49. CTPA identifying additional features that can be detected
supporting a diagnosis of pulmonary embolism. There is a
right-sided pleural effusion and dilatation of the right
ventricle (arrow)
51. Dual Energy CT (DECT)
• based on the premise that materials behave differently when exposed
to X-ray photons of different energies.
• Higher molecular weight materials show a greater difference in X-ray
attenuation when exposed to low and high energy levels as compared
to lower molecular weight materials, due to the higher probability of
the photoelectric effect in high molecular weight materials when
interacting with lower energy X-rays
• Current two DECT techniques:
1) Dual-source CT scanners
2) Single-source CT scanners with rapid voltage switching
52. Iodine Mapping
• Data sets derived from DECT can be used to generate iodine maps
• allow visualization of the distribution and amount of iodine within the
lung after intravenous contrast administration (pulmonary perfusion)
• The use of iodine mapping in DECT is
• improve the accuracy of the diagnosis of PTE, especially for
segmental and subsegmental PTE which may not be detected by
CT
• Wedge-shaped perfusion defects are seen in acute PE, which has
been shown to correlate well with pulmonary perfusion on
scintigraphy
53. CT slices, in coronal and sagittal
views (A and B, respectively),
showing extensive filling defects
affecting the pulmonary artery
branches, mainly in the left lower
lobe.
Dual-energy CT, in axial and sagittal
views (C and D, respectively),
demonstrating an extensive
perfusion defect in the left lower
lobe due to acute PTE.
54. Axial CT slice (A) and iodine map created by the subtraction technique (B)
showing bilateral filling defects in the subsegmental branches in
correlation with the associated perfusion defects.
55. Limitations of DECT
• Scanner-related: high cost; relatively long image processing time; and
smaller field of view of the B tube, which may not include the
peripheral portion of the thorax
• Patient-related: obesity can which can increase image noise,
compromising the structural and functional analysis, and, in some
cases, patient weight exceeds the allowable limit of the DECT scanner.
• Interpretation: there are a limited number of radiologists who are
familiar with the technique; and the terminology has yet to be
standardized.
56. CTV
• CTV can also be used in the detection of deep vein thrombosis in the
extremities.
• It can be obtained at the same time of CTPA
• CTV can be performed adequately in patients with overlying casts, surgical
material, or wounds.
• Acute DVT on CTV appears as a complete or partial filling intraluminal
hypodense filling defect in a deep vein.
• The vein is typically expanded, and a rim of enhancing venous wall may be
seen. Secondary signs include edema in the adjacent tissues
• Chronic DVT manifests on CTV with small vessels, recanalization of
thrombus, calcifications, and thickened venous veins
• The mean CT attenuation of DVT is between 31 and 65 HU
57. MR angiography (MRA)
• provide both morphological and functional information.
• MRI protocols:
• free-breathing steady-state free precession
• post-contrast T1-weighted 3D-contrast enhanced MRA for pulmonary
angiogram
• T1-weighted 4D-contrast enhanced first pass perfusion study for lung
perfusion
• T1-weighted volumetric interpolated 3D gradient-echo for mediastinal and
pleural disease
• MRPA findings of PE include filling defects, complete absence of
vessel enhancement, dilatation of the main pulmonary artery, and
caliber change with post-stenotic dilatation
58. • In comparison with CTPA, MRPA had lower sensitivities for detecting
PE, especially in peripheral pulmonary arteries
• MRPA should be considered only in well-experienced facilities and
only for patients with contraindications to standard tests
• MRPA might be appropriate instead of CTPA and VQ scintigraphy only
in patients with intermediate pretest probability with a positive D-
dimer or high pretest probability
59. Axial MR image of the heart showing multiple filling defects
in the main pulmonary arteries, suggestive of pulmonary
embolism (arrows).
60. Lower extremity ultrasound
• Important step in the diagnostic algorithm for suspected VTE
• Acute deep vein thrombus manifests on US as hypoechoic intravascular
material that expands the venous lumen.
• DVT may be fully occlusive or non-occlusive, and the affected vessel lumen
will not collapse under compression
• Color Doppler may be useful to demonstrate a lack of flow, but caution
with this approach is recommended as blooming of color maps may
obscure small thrombus.
• Spectral Doppler waveforms can be observed for appropriate response to
calf compression; a lack of response being indicative of intervening
thrombus between the point of observation and the calf.
• Lack of normal respiratory phasicity of the more proximal veins may
indicate central venous thrombus.
61. Echocardiography
• Transthoracic echocardiography (TTE) has limited sensitivity and
specificity for diagnosis of acute PE.
• A negative echocardiogram cannot exclude a diagnosis of PE, and
similarly positive findings can be secondary to cardiorespiratory
disease in the absence of PE.
• Presence of right sided cardiac thrombus may be seen
RV overload criteria (seen in 30–40% of patients with PE)
• dilated diastolic RV diameter >30 mm or RV/LV >1
• systolic flattening of interventricular septum or
• acceleration time <90 ms
62. CONCLUSION
• CTPA is the current gold standard in the diagnosis of acute PE with high
accuracy, wide availability, and rapid turnaround time.
• Combining CTPA with clinical pre-test probability of PE yields superior
sensitivity and specificity than imagining alone.
• VQ scanning is indicated in patients who are young, pregnant or cannot get
contrast.
• Chest radiographs are useful in excluding other causes of chest pain.
• MRPA can provide good accuracy in centers with adequate expertise.
• In pregnant patients, lower extremity ultrasound is recommended as the
initial imaging modality.
• Echocardiography is useful in triaging high-risk PE patients.
• Invasive pulmonary angiography is reserved for those patients needing
endovascular intervention.