Prof. Mona Mansour Professor of Pulmonary Medicine Ain Shams University

Pulmonary embolism 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 thrombo-embolism

Diagnosis Pulmonary embolism may be difficult because no reliable non invasive imaging method. In United States: estimated incidence of PE exceeds cases per year. 30% mortality if untreated. Mortality in treated cases 2.5%

1- Clinical assessment: Wells score Geneva score

Points Wells score Points variable Points Revised Genevascore Variable Predisposing factors +1.5 Pervious DVT or PE +1 Age >65 yrs Recent surgery or immobilization +3Pervious DVT or PE +1 Cancer +2 Surgery or fracture within 1 month +2 Active malignancy Symptoms +3 Unilateral lower limb pain +1 Haemoptysis +2Haemoptysis Clinical signs +1.5 Heart rate > Heart rate > 95 beats +3 Clinical signs of DVT Alternative diagnosis than PE +4 Pain in lower limb vein at palpation and unilateral oedema TotalClinical probabilityTotalClinical probability > 7 Low Intermediate High > 11 Low Intermediate High

2- Serological tests: D Dimer (ELISA) Screening test in patients with low and moderate probability clinical assessment a. Normal D-Dimer has almost 100% negative predictive value b. Raised D-Dimer is non specific: we need further investigation

3- Radiological features: Plain film: Fleishner sign: Enlarged pulm. Artery (20%) Hampton hump: Perpheral wedge of air space opacity implies lung infarction (20%) Westermark sign: Regional oligaemia (10%) Pleural effusion: 35% Elevated diaphragm:

Nuclear medicine V/Q scan: High probability scan is defined as two or more unmatched segmental perfusion defects. Normal perfusion scan is very safe for excluding PE. Combination of non diagnostic V/Q scan + low clinical probability can exclude PE.

Computed Tomography with Pulmonary Angiography (CTPA): Acute pulmonary embolism: Filling defect (polo mint) sign. Central filling defect from thrombus surrounded by a thin rim of contrast. Saddle embolus

Computed Tomography with Pulmonary Angiography (CTPA): Chronic pulmonary embolism: Webs or bands Abrupt narrowing or complete obstruction of pulmonary arteries

Computed Tomography with Pulmonary Angiography (CTPA): Acute or Chronic right ventricular dysfunction: a- Abnormal position of interventricular septum b- RVD: LVD ratio > 1

Computed Tomography with Pulmonary Angiography (CTPA): Subacute to Chronic emboli: a- Pulmonary infarction B- Pulmonary hypertension C- Chronic cor pulmonale

Gadolinium Enhanced Pulmonary Magnetic Resonance Angiography (MRI): Pulmonary arterial signs in MRA: a- abrupt decrease B- parenchymal sign C- pulmonary hypertension The use of MR venography could also help diagnosis of PE

MRI is more expensive than VQ scan, but cheaper than angiography. MRI does not require hospitalization Non nephrotoxic No ionizing radiation Safe rapid, accurate, cost effective imaging.

Compression Ultrasonography (CUS) Diagnosis of DVT may indirectly suggest the diagnosis of PE Anticoagulants are most often the initial therapy for DVT and PE

Limitations: Not Definite for PE Normal proximal bilateral venous ultrasonography don't rule out PE

Pulmonary angiography: Invasive CT angiography offers better results, non invasive

Echo cardiography: In shock or hypotension, absence of echo signs of Rt. over load or dysfunction excludes PE.