Chronic pulmonary emboli
Pulmonary
endarterectomy for chronic thromboembolic pulmonary hypertension with active Crohn’s disease. a Preoperative computed tomography scan of the lung showing showed proximal chronic pulmonary emboli. b Preoperative computed tomography scan of the lung showing a nontuberculous mycobacterial infection. c Preoperative computed tomography scan of the lung showing aspiration pneumonia. d Preoperative lung perfusion scintigraphy showing multiple segmental defects. e, f Preoperative pulmonary artery angiograms showing intimal irregularities and abrupt narrowing of both pulmonary arteries
Chronic pulmonary emboli are mainly a consequence of incomplete resolution of pulmonary thromboembolism.
Radiographic features
CTPA
- vascular CT signs include
- direct pulmonary artery signs
- complete obstruction
- partial obstruction
- eccentric thrombus
- calcified thrombus - calcific pulmonary emboli
- pulmonary arterial bands/pulmonary arterial webs
- post-stenotic dilatation
- signs related to pulmonary hypertension
- enlargement of main pulmonary arteries
- the peripheral pulmonary arteries in affected segments may be narrowed
- pulmonary arterial calcification
- tortuous pulmonary vessels
- right ventricular enlargement/hypertrophy
- signs of systemic collateral supply
- enlargement of bronchial and non-bronchial systemic arteries
- direct pulmonary artery signs
- parenchymal signs (often non-specific on their own):
- scars
- mosaic perfusion pattern
- focal ground-glass opacities
- bronchial anomalies
Nuclear medicine: V/Q scan
Some publications suggest that V/Q scanning may be more sensitive but less specificthan CTPA in detecting chronic pulmonary embolic burden.
Complications
Increased vascular resistance due to obstruction of the vascular bed leads to pulmonary hypertension.
Differential diagnosis
Differential considerations on a CTPA include :
- perivascular pulmonary edema
- artefacts/interpretational errors
- motion: breathing artefact
- flow-related artefact
- streak artefact
- misinterpretation
- due to incorrect window settings
- misinterpretation of veins as arteries
- pulmonary arterial catheter
- intrinsic intraluminal tumor
Siehe auch:
- Lungenarterienembolie
- chronisch rezidivierende Lungenembolie Szintigraphie
- Verkalkungen in pulmonalen Emboli
und weiter:
Assoziationen und Differentialdiagnosen zu chronisch rezidivierende Lungenembolie: