Emergency Cardiopulmonary Imaging

Non-Traumatic Emergency Cardiopulmonary ImagingAwad Bessar, MDProfessor of RadiodiagnosisZagazig UniversityClinical ApproachIssues to be ConsideredImaging of Acute Chest PainCardiogenic acute chest painNon-Cardiogenic acute chest pain:AorticPulmonary infarction and embolismNon-thoracic causesImaging of thoracic fluid and gas collectionPericardial effusionPulmonary effusionPneumothoraxMediastinumMonitoring and Support Devices; Tubes and LinesPart 1

ACUTE CHEST PAIN(a)CaRDIOGENIC ACUTE CHEST PAINCardiac CT ApplicationsCalcium Scoring: provide a quantitative assessment of subclinical atherosclerotic coronary artery disease

Cardiac CT Applications52-year-old woman with chest pain. (A) Curved planar reconstruction from a coronary CTA demonstrates no evidence of coronary artery disease. (B) Straightened coronary artery view allows measure of caliber along the length of the artery (arrow). Crosssectional view (arrowhead) shows the arterial wall and lumen in a projection similar to intravascular ultrasound.

Cardiac CT Applications; Coronary Artery Evaluation

83-year-old man with chest pain. (A) Curved planar reconstructed image of the right coronary artery from a coronary CTA demonstrates multiple areas of proximal stenosis (arrows). (B) Coronary angiogram with injection of the right coronary artery shows similar areas of stenosis (arrows).AAn 8 mm thick maximum intensity projection in a slightly oblique para-axial projection (a) and 3-D reconstruction (b) in a patient with left anterior descending coronary artery stenosis (arrow). Corresponding coronary angiography (c).

BAn 8 mm thick maximum intensity projection in a slightly oblique para-axial projection (a) and 3-D reconstruction (b) in a patient with left anterior descending coronary artery stenosis (arrow). Corresponding coronary angiography (c).

CAn 8 mm thick maximum intensity projection in a slightly oblique para-axial projection (a) and 3-D reconstruction (b) in a patient with left anterior descending coronary artery stenosis (arrow). Corresponding coronary angiography (c).

a Multiplanar reconstruction showing an eccentric stenosis of the left main coronary artery (small arrow) and of the left anterior descending coronary artery (large arrow). b Corresponding lesions in invasive angiography. In addition, a left circumflex stenosis is present (not shown as an MDCT image).AB

Noncalcified plaque (arrow) in the proximal left anterior descending coronary artery associated with significant luminal stenosis in a 65-year-old male patient

Noncalcified plaque (arrows) of the proximal left anterior descending coronary artery associated with (subtotal) occlusion in a 48-year-old male patient presenting with a vague history of recent episodes of chest pain.

Densely calcified plaque in the proximal and mid left anterior descending coronary artery (arrow) in a 65-year-old female patient presenting with chronic angina pectoris

Mixed plaque with calcified (arrow) and noncalcified components (arrowhead) in the mid left anterior descending coronary artery associated with mild luminal narrowing in a 55-year-old female patient presenting with atypical angina pectoris.

Coronary artery stenosis. Coronary CTA shows a high-grade stenosis (arrow) due to non-calcified plaque (arrowheads) in the proximal LADNon-Cardiogenic Acute Chest PainChest radiography usually represents the first imaging modality performed in patients presenting with acute chest pain.CXR can diagnose the following:PneumothoraxPneumomediastinumRib fracturesAcute infections. Aortic aneurysms or dissections (lower sensitivity)Pulmonary embolism (lower sensitivity)(b)aortic causes of ACUTE CHEST PAINAortic DissectionWidening of the superior mediastinum Displacement of aortic wall calcificationsIn Aortic dissection an intima flap is seen in only 70% of cases.

Typical Aortic Dissection, Intramural Hematoma and Penetrating Aortic Ulcer.Stanford classificationStanford Type A lesions involve the ascending aorta and aortic arch and may or may not involve the descending aorta. Stanford Type B lesions involve the thoracic aorta distal to the left subclavian artery.

DeBakey classification type I= ascending, arch and descending aorta: type II= only ascending aortatype III= only descending aorta.

The Stanford classification has replaced the DeBakey classification Classic Aortic Dissection is the most common entity causing an acute aortic syndrome (70%).Incidence: 1-10 : 100.000 mostly menrarely < 60 year (etiology = media degeneration)hypertension > 70%Type A mortality 1-2% per hour after onset of symptoms, total up to 90% non-treated, 40% when treated.1 year survival Type B up to 85% if medically treated (5 year > 70%)

LEFT: Type A dissection with clear intimal flap seen within the aortic arch.RIGHT: Type B dissection. Entry point distal to left subclavian artery.Type B dissection. Green arrow indicates entry. False lumen is indicated by yellow arrows and is seen spiraling around the true lumen.

True lumen:-Surrounded by calcifications (if present)-Smaller than false lumenUsually origin of celiac trunk, SMA and right renal artery

False lumen: Flow or occluded by thrombus (chronic). Delayed enhancementWedges around true lumen (beak-sign)Collageneous media-remnants (cobwebs)Larger than true lumenCircular configuration (persistent systolic pressure)Outer curve of the archUsually origin of left renal arterySurrounds true lumen in Type A dissectionCollageneous media-remnants (cobwebs) are only seen in the false lumen.

The compressed true lumen is seen on the inner side and is brighter than the false lumen.Thrombus formation within the false lumen.The true lumen usually is smaller as the false lumen

Aortic dissection in a 72-year-old patient. Non-contrast CT scan (a) shows displacement of some calcifications toward the aortic lumen. The contrast-enhanced CT scan at the same level (b) clearly demonstrates an intimal flap in the aortic arch with calcifications along itMassive hematoma caused by rupture of the dissected aorta into the mediastinum and pleural cavity, no pericaldial hematoma.

Imminent rupture of AAA. Axial CTA shows a large outpouching (arrow) near the bifurcation of the abdominal aorta into the iliac arteries. Note the small crescent-shaped area of hyperdensity (arrowhead) within the large thrombus anteriorly. Aneurysm with thrombus versus thrombosed dissection

It can be difficult to differentiate an aneurysm with thrombus from a dissection with a thrombosed false lumen. If there are intima calcifications this will be very helpfull.A false lumen displaces the intimal calcifications.LEFT: Dissection with a thrombosed false lumen. RIGHT: Aneurysm with thrombus on the inner side of the intimal calcifications.Abdominal aortic aneurysm

(c)pulmonary causes of ACUTE CHEST PAINPulmonary Embolism; FindingsEndoluminal clot: This is seen as a partial intravascular central or marginal filling defect surrounded by contrast forming an acute angle with the vessel wall (polo mint or tram line sign). A complete intravascular filling defect occupies the entire vessel, without rim enhancement.

Dilated pulmonary artery proximal to the clot.Pulmonary Embolism; FindingsOther non-specific signs: Peripheral wedge-shaped consolidation represents a pulmonary infarction especially if it is non-enhancing and displays a thick vessel running towards the bubbly consolidation (vascular sign).

Pleural effusion and right-heart dilation. The central pulmonary arteries may be dilated in subacute PE.

Acute PE. CTA chest shows large globular filling defects within the distal right main pulmonary artery(arrow) and filling defects within segmental pulmonary arteries in the left lower lobe (arrowheads) and a large rightsidedpleural effusion.

Chronic PE. CTA chest shows non-occlusive intraluminal filling defects (arrows) adherent to the wall and multiple peripheral cavitary infarcts (arrowhead).

Septic emboli. Axial CT chest of an intravenous drug abuse patient shows multiple peripheral cavitary nodules (arrows) due to septic emboli. Echocardiography demonstrated tricuspid valve vegetations.Pulmonary Embolism; SignsHampton Hump Sign

Westermark sign

Hampton Hump SignPulmonary infarction secondary to pulmonary embolism produces an abnormal area of opacification on the chest radiograph, which is always in contact with the pleural surface. The opacification may assume a variety of shapes. When the central margin is rounded, a humpis produced, as described by Hampton and Castleman.

Lung window shows a focal subpleural area of consolidation in the left lower lobe (arrows). This hump-shaped area of opacification represents pulmonary infarction secondary to pulmonary embolism. there are also small bilateral pleural effusions, which are commonly seen with acute pulmonary emboli.

CT with mediastinal windowing shows low-attenuation filling defect, which represents a saddle embolus (arrows) bridging the lingular and left lower lobe pulmonary arteries

Westermark signThis sign refers to oligemia of the lung beyond an occluded vessel in a patient with pulmonary embolismWestermark sign

PA chest radiograph shows oligemia of the right lung, the so-called Westermark sign. Note how the vessels on the right are diminutive compared with those on the left. As a result, the right hemithorax appears hyperlucent.Westermark sign

CT with lung windowing better shows the diminution of vessels on the right compared with the left. There is also a right pleural effusionWestermark sign

CT with mediastinal windowing shows thrombus expanding and filling the main and right pulmonary arteries (arrows). Pulmonary InfarctionPulmonary infarction (usually haemorrhagic) is most commonly caused by pulmonary embolism (PE) in combination with chronic left heart failure. It occurs in the minority (10 - 15%) of patients with PE

Plain radiographyWedge shaped (less often rounded) pleurally based opacification (Hampton hump) without air bronchiograms.More often in the lower lobes.In the case of pulmonary hemorrhage without infarction the opacities resolve, usually within a week, by maintaining their shape (the so called "melting sign").In the case of infarction it requires months to heal and will leave a linear scar.Elevation of the ipsilateral hemidiaphragm.

Pulmonary infarction. (A) Chest film made 3 days after open-heart surgery demonstrates a very irregular opacity at the right base (pneumonia versus pulmonary embolization with infarction). (B) On a film made 5 days later, the consolidation is seen to have reduced in size yet to have retained the same general configuration as on the initial view. The diagnosis of pulmonary embolism was confirmed by a radionuclide lung scanCTLike on CXR, wedge shaped (less often rounded) pleural based opacification (Hampton hump) without air bronchograms and often occurs in the costophrenic sulcus. Convex borders with a halo sign due to adjacent hemorrhage.Feeding vessel with visualization of the thrombus.Sometimes scattered areas of low attenuation within the lesion (necrosis) and sometimes enhancement of the perimeter of the infarct.Cavitation is seen in septic embolism and in infection of a bland infarct.

Pneumothorax

A large right-sided spontaneous pneumothorax (left in the image). An arrow indicates the edge of the collapsed lung

CT scan of the chest showing a pneumothorax on the person's left side (right side on the image). A chest tube is in place (small black mark on the right side of the image), the air-filled pleural cavity (black) and ribs (white) can be seen. The heart can be seen in the center

Chest X-ray of left-sided pneumothorax (seen on the right in this image). The left thoracic cavity is partly filled with air occupying the pleural space. The mediastinum is shifted to the opposite side.(d)other causes of ACUTE CHEST PAIN

CTA image shows a main pulmonary artery aneurysm (arrow) with resultant significant compression of the left main stem coronary artery (arrowhead).Pulmonary Artery Aneurysm Esophageal Perforation/Dissection

Esophageal perforation. Axial CECT shows a large amount of oral contrast layering posteriorly in the right hemithorax (small arrow), with some contrast and air seen within and adjacent to the esophagus (arrow).Superior Vena Cava Syndrome

SVC thrombosis. Venous phase CTA shows partial enhancement of (arrowhead) a large low-density thrombus (arrow) in the superior vena cava, representing tumor thrombusCardiac AneurysmOn a chest radiograph the cardiac outline appears bulging in the region of the aneurysm, and there may be associated compensatory hypertrophy or pulmonary oedema. Cardiac aneurysms tend to involve the left ventricle because the blood there is under greatest pressure.

Pericaridal Effusion

2D transthoracic echo of pericardial effusion

Water bottle-shaped heart

This image is from a patient with malignant pericardial effusion. Note the "water-bottle" appearance of the cardiac silhouette in the anteroposterior (AP) chest film.Part 2

thoracic fluid and gas collectionPleural FluidA pleural effusion is a collection of fluid within the pleural cavity.There are many causes of pleural effusion that are broadly split into transudates and exudates. This categorization relies upon the protein concentration of the pleural fluid: a protein concentration > 30g/l suggests an exudate.

Plain radiographyCXR (erect):Blunting of the costophrenic angleOccasionally, blunting of the cardiophrenic angleFluid within the horizontal or oblique fissuresWith large volume effusions, mediastinal shift occurs away from the effusionWith underlying collapse, mediastinal shift may occur towards the effusionCXR (supine):Fluid is dependant and collects posteriorlyThere is no meniscus and only a veil-like appearance to the hemithorax

UltrasoundUltrasound allows the detection of small amounts of pleural locular fluid, with positive identification of amounts as small as 3 to 5 ml, which cannot be identified by x-rays as it is only capable of detecting volumes above 50 ml of liquid.Allows an easy differentiation of pleural locular liquid and thickened pleura. Efficient in pinpointing thoracocentesis, even in small fluid collections.The ultrasound image of pleural effusion is characterized by an echo-free space between the visceral and parietal pleura.

Right pleural effusion. Sagittal image of the right upper quadrant demonstrates an anechoic fluid collection above the right hemidiaphragm consistent with a pleural effusion (arrow)

Empyema. Ultrasound image of a large parapneumonic effusion demonstrates thick septations (white arrows) within the fluid in keeping with an exudate. Frank pus was aspirated during thoracentesis

Free pleural effusion. Posteroanterior chest radiograph demonstrates the meniscus sign (arrows) in a large free right pleural effusion

Empyema. Axial CECT shows a peripherally enhancing elliptical-shaped pleural collection with an airfluid level (arrow). Note the thickening of the extrapleural subcostal fat (arrowhead), seen with chronic empyemas.PneumomediastinumPneumomediastinum is the presence of extraluminal gas within the mediastinum. Gas may come from lungs, trachea, central bronchi, oesophagus, and the neck or abdomen.Aetiology-Blunt chest trauma-Secondary to chest, neck, or retroperitoneal surgery-Esophageal perforation: oBoerhaave syndromeoEndoscopic interventionoEsophageal carcinoma-Tracheobronchial perforation: oLacerationoBronchial stump dehiscenceoBronchoscopyoTracheostomyoLaryngeal fracture-Vigorous exercise: oChildbirthoWeightliftingoValsalva maneuver

-Asthma-Barotrauma: DivingVentilator : most commonly secondary to ards with positive pressure ventilation-Subcutaneous emphysema, pulmonary interstitial emphysema-Stab wound-Infection: TuberculosisHistoplasmosisDental or retropharyngeal infectionMediastinitis-Idiopathic

Radiological featuresSubcutaneous emphysemaElevated thymus: Thymic wing signAir anterior to pericardium: PneumopericardiumAir around pulmonary artery and main branches: Ring around artery signAir outlining major aortic branches: Tubular artery signAir outlining bronchial wall: Double bronchial wall signContinuous diaphragm sign: Due to air trapped posterior to pericardiumAir between parietal pleura and diaphragm: Extrapleural signAir in pulmonary ligament

Loculated pneumomediastinum in an infant with respiratory distress syndrome. Frontal chest radiograph obtained 5 days after birth shows a rounded radiolucent opacity over the mediastinal area (arrows). This image was not present in a previous radiographic study done 48 hours before (not shown)Pneumomediastinum in acute respiratory distress syndrome. High-resolution CT scan shows diffuse bilateral areas of ground-glass opacity with a superimposed linear (crazy-paving) pattern consistent with acute respiratory distress syndrome. Irregular hyperlucent areas, representing focal areas of pulmonary laceration, are seen in the right upper lobe (white arrows). Extensive pneumomediastinum (black arrows) and small bilateral pleural effusions also are seen.

Acute MediastinitisThis is a rare but serious condition due to acute infection of the mediastinum. Chest CT is the best imaging modality of choice, which aids the diagnosis and guides percutaneous drainage of the mediastinal collection.Causes include esophageal/pharyngeal perforation, post-sternotomy, extension of infection from elsewhere and may be associated with empyema

Mediastinitis. Axial CECT shows a small pocket of enhancing loculated abscess (arrow) within the peripherally enhancing fluid collection (arrow head) in the anterior mediastinum. A small right pleural effusion and moderate left loculated pleural collectionPart 3

Lines, Tubes, and Devices1-VenousPercutaneous Indwelling Central CatheterCentral venous catheterPulmonary artery catheterVenovenous or venoarterial extracorporeal life supportStents

Normal position of a percutaneous intravascular central catheter (PICC) line. A. Standard posteroanterior chest radiograph demonstrates the left upper extremity PICC with tip in the distal left brachiocephalic vein. B. Note the greater conspicuity of the same percutaneous intravascular central catheter on the right anterior oblique radiograph at low kVp technique

Normal position of central venous catheters. Catheter entering from right internal jugular vein with tip in the distal right brachiocephalic vein, and catheter (double lumen) entering from left subclavian vein with tip in the superior vena cava illustrates location of venous anatomyComplications Secondary to Central Venous Catheters:MalpositionPneumothoraxVascular laceration (hemothorax, chest wall/neck/mediastinal hematoma)Infection (possible source of septic emboli)Catheter fragmentation and embolizationVenous thrombosisVenous stenosis

Malpositioned central venous catheters. Posteroanterior and lateral radiographs demonstrate a central venous catheter in the azygos vein (arrowheads).Neck hematoma (asterisk) after right internal jugular line placement attempt. Note the endotracheal tube tip is in the right main bronchus.

Fatal right hemothorax after right internal jugular line placement attempt in a patient with undiagnosed idiopathic thrombocytopenic purpura

Posteroanterior and (D) lateral radiographs demonstrate a right subclavian catheter with tip overlaying the right clavicular head (arrow), as well as catheter fragments in both the right and left pulmonary arteries (arrowheads).

Normal position of a pulmonary artery catheter placed through the right internal jugular vein, with tip in the proximal right pulmonary artery (arrowhead). Note the right chest wall port (large arrow) with tip in the superior vena cava (small arrow).Pulmonary artery pseudoaneurysm secondary to peripheral placement of a pulmonary artery catheter. Bright red blood in endotracheal tube immediately after inflation of the pulmonary artery balloon. Focal hemorrhage in the right lower lung (asterisk).

Pulmonary artery pseudoaneurysm secondary to peripheral placement of a pulmonary artery catheter. Bright red blood in endotracheal tube immediately after inflation of the pulmonary artery balloon. Pulmonary angiogram after embolization with several 2- to 4-mm Gianturco coils demonstrates absent blood flow in the pseudoaneurysm

Pulmonary artery pseudoaneurysm secondary to peripheral placement of a pulmonary artery catheter. Bright red blood in endotracheal tube immediately after inflation of the pulmonary artery balloon. Selective pulmonary angiogram of the right middle lobe demonstrates a 2-cm pseudoaneurysm arising from a subsegmental artery.

Venoarterial extracorporeal life support in a patient with acute respiratory distress syndrome secondary to streptococcal pneumonia. The tip of the venous cannula (arrowheads) is in the right atrium (arrow) and the tip of the arterial cannula (open arrowheads) is in the distal common carotid artery (large arrow).

Wire-mesh stent in the superior vena cava as seen on (A) posteroanterior and (B) lateral radiographs2- ArterialIntraaortic balloon pumpVenoarterial extracorporeal life supportStents

Normal position of an intraaortic balloon pump with metallic tip at the inferior aspect of the aortic knob (arrow). Note the radiolucency of the inflated balloon (arrowheads).

Abnormal intraaortic balloon pump position, with tip in the left subclavian artery (white arrow). Note the pulmonary artery catheter in correct position in the right descending pulmonary artery (black arrow) and the endotracheal tube in correct position with tip 4 cm above the carina (arrowheads).3- CardiacPacemakerImplantable cardiac defibrillatorLeft venticular assist deviceAtrial septal defect closure device

Temporary transvenous pacemaker placed through the common femoral vein at the groin, through the inferior vena cava, right atrium across the tricuspid valve and into the right ventricle with tip in the right ventricular outflow tract (arrow). There is an adjacent pulmonary artery catheter, also placed from a femoral approach, with tip in the left pulmonary artery (arrowhead). The patient had complete heart block that later required a permanent pacemaker.

Dual-chamber pacemaker as demonstrated on (A) posteroanterior and (B) lateral radiographs. Device was placed for syncope and bradycardia 14 years earlier. Generator is in the left anterior chest wall with lead tips in the right atrium (arrowheads) and right ventricle (arrows).Biventricular pacemaker in a patient with ischemic cardiomyopathy

Two examples of broken pacemaker leads. A. Lead broken beneath the left clavicular head (arrow). B. Lead broken (arrow) in the chest wall near the generator.Twiddler syndrome. Single lead pacemaker with lead tip in right ventricle. A. Note the generator position and the adjacent redundant lead after initial insertion. B. Three years later the generator has migrated inferiorly and medially, and the redundant lead in the chest wall has unwound.

Pacemaker and implantable cardiac defibrillators. Pacemaker in the right chest wall with lead tip in the right ventricle (large arrow, top) and the larger implantable cardiac defibrillator in the left chest wall with lead tips in the right atrium (arrow) and right ventricle (arrowhead). Note the right pneumothorax, a complication of pacemaker placementEpicardial implantable cardiac defibrillator patches (arrows) that required thoracotomy to implant, with epicardial leads that extend to a device in the anterior abdominal wall, as demonstrated on (A) posteroanterior and (B) lateral radiographs.

HeartMate left ventricular assist system

Large wire coronary artery bypass graft markers (arrows) as seen on (A) posteroanterior and (B) lateral radiographs.4- AirwayEndotracheal tubeTracheostomy tubeIntratracheal oxygen catheterStents

Abnormal endotracheal tube with balloon inflated positioned within the pharynx. High position of an endotracheal tube may cause vocal cord injury5- EsophagusFeeding tubeNasogastric or oral-gastric tubesIntraesophageal manometerTemperature probepH probeStentAntireflux devicesGastric banding

Correct position of feeding tubes

Incorrect position of esophageal tubesCoil-type stent in the esophagus as seen on (A) posteroanterior and (B) lateral radiographs.

Gastric banding for morbid obesity

6- PleuralChest tubes

Two chest tubes. One punctured the lung, with resulting large pulmonary hematoma. A. Chest radiograph shows a large hematoma in the right lung. B. Computed tomography demonstrates the high attenuation hematoma surrounding the intraparenchymal chest tube, and a second chest tube in the pleural space posteromedially