Pulmonary embolism.pptx by mcac rms ct findings What Is Pulmonary Embolism (Pulmonary Embolus)? A pulmonary embolism is a sudden blockage in your pulmonary arteries, the blood vessels that send blood to your lungs. It usually happens when a blood clot in the deep veins in your leg breaks off and travels to your lungs. A blood clot that travels to another part of your body is called an embolus. When an embolus blocks a blood vessel it's called an embolism. When a pulmonary embolus blocks blood flow to your lungs, it's called a pulmonary embolism The most common cause of a pulmonary embolism is a the breaking off of a blood clot in your leg's deep veins, known as deep vein thrombosis (DVT). Other, rare causes of a pulmonary embolism include: Air bubbles DVT in the upper body Fat embolus, usually from a severely broken bone Tumors You are more likely to develop blood clots if you have risk factors such as: Cancer Family history of blood clots or clotting disorders Heart disease Health history of blood clots or clotting disorders Long-term use of birth control pills or estrogen therapy A pulmonary embolism is also more likely to develop after: Childbirth Heart attack or stroke Long plane or car rides Long-term bedrest Severe injuries, burns or fractures Surgery Pulmonary Embolism Symptoms You may not have any symptoms of a pulmonary embolism, depending on the size of the clot and your overall health. As blood flow becomes more and more blocked, you may experience symptoms such as: Coughing, including a cough that produces bloody mucus Dizziness Heart palpitations, sensations of your heart racing or pounding Leg pain or swelling Sharp and sudden chest pain Shortness of breath that worsens with exertion Pulmonary Embolism Complications A pulmonary embolism can be life-threatening without treatment. It can cause several complications, including: Cardiac arrest, when your heart suddenly stops beating Cardiac arrhythmia, an irregular heart rhythm Pleural effusion, fluid buildup in the membrane around your lungs (pleura Pulmonary hypertension, high blood pressure in your lungs Pulmonary infarction, when lung tissue dies Diagnosing a Pulmonary Embolism To diagnose a pulmonary embolism, your doctor does a physical exam, asks about your symptoms and orders one or more tests such as: Blood tests to check if you have an increased risk of blood clotting Chest X-rays to take pictures of your heart and lungs CT pulmonary angiography, using X-rays and specialized computers to create cross-sectional, 3D images of your lungs and pulmonary arteries Doppler ultrasound, using sound waves to look for deep vein thrombosis in your legs Echocardiogram to view your heart's structures and blood vessels Lab tests, such as pulse oximetry to measure oxygen levels in your blood or arterial blood gas tests to measure the balance of oxygen and carbon dioxide Pulmonary angiogram, using a small, hollow tube (catheter) and a contrast dye to see how blood flows through the pulmonary A

1. LUBNA AL TAMIMI.MD
DIAGNOSTIC RADIOLOGY SPECIALIST
ROYAL MEDICAL SERVICES

2.  Definition and clinical presentation
 Wells criteria
 Radiographic features
 Management

3.  pulmonary embolism (PE) refers to embolic
occlusion of the pulmonary arterial
system. The majority of cases result from
thrombotic occlusion, and therefore the
condition is frequently termed pulmonary
thromboembolism

4. Non-thrombotic pulmonary emboli sources
include :
 gas embolism, e.g. air embolism, carbon dioxide embolism
 fat embolism
 tumor embolism: comprised of tumor thrombus
 infectious agents
◦ parasitic embolism
 amniotic fluid embolism
 catheter embolism
 particulate material embolism, e.g.
◦ talc embolism
◦ metallic pulmonary embolism
 barium embolism
 mercury embolism

5. Clinical presentation
 history of recent immobilization or surgery, active
malignancy, hormones, or a previous episode of
thromboembolism.
 suggestive features of PE such as:
 tachycardia
 dyspnea
 pleuritic chest pain
 Hemoptysis
 clinical signs of deep venous thrombosis (DVT)
◦ asymmetric pitting lower extremity edema
◦ prominent superficial collateral vessels
◦ tenderness to palpation along the deep venous system

7. Interpretation
 Can be applied in either three tier or two tier
models:
 Two tier:
 ≤4:PE unlikely
 >4: PE likely
 PE unlikely: order D-dimer
 PE likely: order CTPA

9. D-dimer is commonly used as a screening test in
patients with low risk (PE is unlikely), in these
patients:
 normal D-dimer ( 100% negative predictive value)
 raised D-dimer , non-specific: it indicates the
need for further testing .
 In patients with high risk (PE is likely), a D-dimer
test is not helpful because a negative D-dimer
result does not exclude pulmonary embolism in
more than 15% of the tests .

11. hemodynamic
 massive PE
 submassive PE
 low-risk
temporal pattern
 acute
 subacute
 Chronic
anatomy
 Saddle
 lobar
 segmental
 subsegmental

12. Radiographic features
 Depends to some extent on whether it
is acute or chronic. Overall, PE has a
predilection for the lower lobes.

13.  Chest radiography is neither sensitive nor
specific . It is used to assess other differential
diagnostic possibilities such
as pneumonia and pneumothorax rather than for
the direct diagnosis of PE.
Described chest radiographic signs include:
 Fleischner sign: enlarged pulmonary artery .
 Hampton hump: peripheral wedge airspace
opacity .
 Westermark sign: regional oligemia .
 pleural effusion
 Chang sign : dilated right descending pulmonary
artery with sudden cut-off

16. Hampton hump refers to a dome-shaped,
pleural-based opacification in the lung most
commonly due To lung infarction due to
Pulmonary embolism.
 the expected apex of this infarction may be
spared due to collateral supply from the
bronchial arterial circulation, leading to the
characteristic rounded appearance of a
Hampton hump.
 In case of infarction, it takes months to
resolve, and it often leaves a linear scar.

20.  CT pulmonary angiography (CTPA) will show filling
defects within the pulmonary vasculature with acute
pulmonary emboli.
 When the artery is viewed in its axial plane the central
filling defect from the thrombus is surrounded by a thin
rim of contrast, which has been called the Polo Mint sign.
-emboli may be occlusive or non-occlusive.
- makes an acute angle with the vessel.
-The affected vessel may also enlarge .
 Acute pulmonary thromboemboli can rarely be detected on
non-contrast chest CT as intraluminal hyperdensities .

22.  In contrast to acute pulmonary embolism,
-are filling defects in the periphery of the
affected vessel
-form obtuse angles with the vessel wall .
-The thrombus may be calcified.

24.  Saddle pulmonary embolism
-large pulmonary embolism that straddles the bifurcation
of the pulmonary trunk, extending to both pulmonary
arteries.
 can completely obstruct both left and right pulmonary
arteries resulting in right heart failure .
 With such extensive embolic burden, signs of right heart
strain are usually present and include:
-dilatation of the right ventricle (RV) (i.e. RV width > left
ventricular width)
-straightening or leftward bulging of the interventricular
septum
-enlargement of the pulmonary trunk

27. - Anticoagulation is provided in patients with no risk of active
bleeding.
- If the emboli are large , thrombolysis is an option.
-In some cases, embolectomy or placement of vena cava filters is
required.
-Anticoagulation treatment for subsegmental pulmonary
embolism maybe driven by considerations on:
* recurrence risk
*bleeding risk
*patient's preferences .
-The right ventricular failure due to pressure overload is
considered the primary cause of death in severe PE .

28.  PE is a serious medical emergency that can
lead to death .
 Order D-Dimer only in low and moderate risk
patients.
 No definitive diagnostic tools, so it needs
collaboration of physical ,laboratory work up
and radiographic imaging.