Thrombotic and Nonthrombotic

Pulmonary Arterial Embolism

By

Gamal Rabie Agmy , MD , FCCP Professor of Chest Diseases ,Assiut University

Acute Pulmonary Embolism Saddle PE :that lodges at the bifurcation of the main

pulmonary artery

Multidetector-CT

Findings

• Partial or complete filling defects in lumen of pulmonary arteries – Most reliable sign is filling defect forming acute

angle with vessel wall with defect outlined by contrast material

– “Tram-track sign” • Parallel lines of contrast surrounding thrombus in vessel

that travels in transverse plane

– “Rim sign” • Contrast surrounding thrombus in vessel that travels

orthogonal to transverse plane

• RV strain indicated by straightening or leftward bowing of interventricular septum

Macdonald S; Mayo J. Semin. Ultrasound CT. 2003;24(4):271-231.

Large saddle thrombus with extensive clot burden. Arrows

demonstrating tram-track sign (A), rim sign (B), complete

filling defect (C), and a fully non-contrasted vessel (D)

Acute pulmonary embolism and deep venous thrombosis (DVT) in a 48-year-old woman. (a) Contrast

material–enhanced pulmonary CT arteriogram (1.25-mm collimation) obtained at the level of the basal

subsegmental pulmonary artery shows multifocal low-attenuation emboli (arrows) in segmental and

subsegmental arteries in the right lower lobe. (b) Contrast-enhanced indirect CT venogram (5-mm

collimation) obtained at the level of the pelvic inlet 3 minutes after injection shows large low-

attenuation thrombi filling the left common iliac vein (arrow).

Acute pulmonary embolism in a 41-yearoldwoman. Coronal gadolinium-

enhanced three-dimensional pulmonary MR angiogram shows a large embolus

(arrows) in the proximal right interlobar artery.

Embolic burden scoring system. Schematic of the pulmonary

arterial tree with scores for nonocclusive emboli according to

vessel. Emboli in a segmental pulmonary artery are given a score

of 1. Emboli in more proximal pulmonary arteries are given a

score based on the total number of segmental pulmonary arteries

supplied.

Helical CT Findings in Chronic PTE

Cardiac abnormalities Right ventricular enlargement

Right atrial enlargement

Thrombi in the right atrium or ventricle*

Vascular abnormalities Eccentric, flattened defect at an obtuse angle with

the vessel wall*

Irregular or nodular arterial wall

Abrupt narrowing of the vessel diameter

Abrupt cutoff of distal lobar or segmental artery

Recanalization of thrombosed vessel

Webs or bands (less frequent)

Parenchymal abnormalities Bronchial artery dilatation

Bronchiectasis

Areas of decreased attenuation in the lung (mosaic

perfusion pattern)

Septic Pulmonary Embolism Septic pulmonary embolism in a 28-year-old intravenous drug abuser with human

immunodeficiency viral infection. Repeated blood cultures disclosed a positive culture

for Nocardia. (a) Radiograph shows multiple cavitary nodules throughout both lungs.

(b) CT scan (10-mm collimation) obtained at the level of the azygos arch

demonstrates the feeding vessel sign (vessel leading directly to the nodule) in several

nodules

Hydatid Embolism

Fat Embolism

Amniotic Fluid Embolism

Tumor Embolism

Air Embolism

Talc Embolism

Cement (Polymethylmethacrylate) Embolism

Iodinated oil embolism

Miscellaneous Foreign Body Embolism