random Flashcards
Usual origin of bronchial arteries?
Descending Aorta at level of carina
Size cutoff for bronchial artery dilatation on CT (ex. Chronic PE)
> 2mm
Disease associated with multiple pulmonary AVMs
HHT
Define massive and submassive PE
Massive:
Systolic pressure less than 90 or drop of more than 40
Submassive:
Hemodynamically stable but echocardio evidence of RV strain
What is rassmussen’s aneurysm
Pulmonary artery aneurysm adjacent to or within a tuberculous cavity
there is a progressive weakening of the arterial wall as granulation tissue replaces both the adventitia and the media. This is then gradually replaced by fibrin, resulting in thinning of the arterial wall, pseudoaneurysm formation, and subsequent rupture with haemorrhage.
What is pulmonary epithelioid haemangioendothelioma
Rare vascular tumor of the lung with low malignant potential
Multiple lung nodules in a random bilateral distribution
What is the cutoff between the ascending and descending aorta?
Origin of the left subclavian artery
What is the mean pulmonary artery pressure in pulmonary hypertension?
> 25 mmHg
What are the causes of vaso-occlusive/constrictive pulmonary hypertension? (6)
chronic hemolytic anemia IV talcosis (IV drug users) Schistosomiasis Tumor thromboembolism Chronic thromboembolism Mediastinal fibrosis
What left sided cardiac diseases cause pulmonary hypertension?
Myocardial failure
Valvular disorder (mitral, aortic)
Atrial or ventricular mass/thrombus
How does pulmonary capillary hemangiomatosis lead to pulmonary hypertension?
Quasi neoplastic proliferation of pulmonary capillaries, causing decrease of drainage into capillary bed. High pressures are subsequently backed up to the pulmonary artery, causing pulmonary hypertension
How does pulmonary veno-occlusive disease lead to pulmonary hypertension?
Spontaneous thrombosis in the pulmonary veins, which travel in the interlobular septa, which limits drainage of blood through the pulmonary veins. There is secondary dilatation of the capillary bed and reflux of pressure into the pulmonary arteries, causing pulmonary hypertension.
What features allow you to differentiate tumor embolism into the pulmonary arteries as opposed to bland pulmonary thromboembolism?
In tumor thrombus, there are beaded multifocal intravascular filling defects, expanding the vessel, with progression over time. There can be enhancement
What is the most common source of lymphangitic carcinoma?
Lung adenocarcinoma
second most common is breast cancer
What are the CT findings of lymphangitic carcinoma?
Thickened septa +/- beading Bronchovascular bundle thickening Polygonal lines Reticular lines Subpleural beading Pulmonary nodules usually coexist unilateral and focal
It is important to look closely for beading and nodules as it allows differentiation with pulmonary edema, which is smooth.
What are the most common causes of cavitary pulmonary metastases?
Squamous cell cancer
- H&N
- Lung
- cervical
GI Adenocarcinoma
TCC
Sarcoma
Post-chemotherapy (other primaries)What are the most common causes of hemorrhagic pulmonary metastases?
Angiosarcoma
Choriocarcinoma
RCC
Melanoma
What are the most common causes of hemorrhagic pulmonary nodules?
Fungal Infection Candidiasis Vasculitis Lymphoma Metastases
TRUE OR FALSE
In the followup of pulmonary metastases, the development of peritumoral hemorrhage or cavitation is a sign of response
FALSE
It can be observed post-treatment, but does not imply tumor response.
What are the most common causes of calcified pulmonary metastases?
Sarcoma
- osteo, chondro, synovial
ADK
- ovary, gastric, thyroid
Giant cell tumorWhat are the most common causes of endobronchial metastases?
Breast
Colorectal
Melanoma
RCC
What are the most common causes of pleural-based metastases?
Lung Breast Ovary Stomach Lymphoma
What are the thoracic imaging findings of Behcet disease?
Thrombosis Pulmonary artery aneurysms infarction Hemorrhage Arteriovenous shunt Intracardiac thrombus
What are the most common ANCA positive vasculitides?
Granulomatosis with polyangiitis (Wegener)
Microscopic polyangiitis
Eosinophilic granulomatosis with polyangiitis (Churg-Strauss)
TRUE OR FALSE
Cavitation of pulmonary lesions is typical of vasculitis
FALSE
It is typical of Wegener’s, but not other vasculitides.
What is Constrictive bronchiolitis?
AKA Obliterative bronchiolitis or bronchiolitis obliterans.
It is a type of bronchiolitis and refers to bronchiolar inflammation with submucosal peribronchial fibrosis associated with luminal stenosis and occlusions.
The condition is characterised by concentric luminal narrowing of the membranous and respiratory bronchioles as a result of submucosal and peribronchiolar inflammation and fibrosis without any intraluminal granulation tissue or polyps/polyposis. There is an absence of diffuse parenchymal inflammation.
NOT THE SAME THING AS COP
What are the causes of constrictive bronchiolitis?
idiopathic
post-infectious
viral, mycoplasma
noxious fume inhalation
neuroendocrine hyperplasia (pulmonary tumourlets)
Graft versus host disease/post transplant
Rheumatoid arthritis
Sarcoid/Swyer-James
Mnemonic: CRITTS
What are the plain radiograph and CT findings in constrictive bronchiolitis?
PLAIN RADIOGRAPH:
Normal or non-specific
Hyperinflation
Attenuation of vascular markings
Reticular/reticulonodular markings
CT SCAN:
Mosaic attenuation pattern (areas of decreased lung attenuation with small vascular markings)
Bronchial dilatation
Bronchial wall thickening
Ground glass opacities
What is diffuse alveolar damage?
DAD is characterized by capillary endothelial and alveolar epithelial damage which results in exudation of fluid and products of cellular breakdown. It is multifactorial, and can be secondary to infections, inhalants, drugs, shock, sepsis and radiation.
It is the histologic pattern associated with ARDS and acute lung injury.
What are the 3 phases of diffuse alveolar damage (histological)?
Acute/exhudative phase: First week after initial insult. There is capillary congestion, interstitial and intra-alveolar oedema associated with fibrin and formation of hyaline membranes. Thrombi may develop.
Organizing/proliferative phase: Occurs after 1–2 weeks and is characterised by fibroblast proliferation admixed with scattered mononuclear inflammatory cells, resulting in the formation of organised granulation tissue. Oedema is not prominent during this phase.
Chronic/fibrotic phase: Characterised by features of interstitial fibrosis, including alveolar septal thickening from collagen deposition.
What are the imaging findings of Legionella pneumonia?
Bilateral multifocal consolidation. Ground glass opacities can be present.
Cavitation can be present in extensive consolidation. Can have subpleural/bronchovascular pattern.
Pleural effusions are common.
What is the most common cause of ARDS?
Pneumonia
What are the imaging findings of the 3 phases of diffuse alveolar damage?
Acute exhudative phase: heterogeneous foci of consolidation and ground-glass opacity with a gravitationally dependent gradient, with more consolidation in the posterobasal portions of the lungs. A diffuse crazy-paving pattern can also be seen. Air bronchograms and small pleural effusions are common.
Organizing/proliferative phase: reticulation and traction bronchiectasis may develop, often having an anterior predominance.
Chronic/fibrotic phase: reticulation and traction bronchiectasis may develop, often having an anterior predominance.
Fibrosis can improve, remain stable or progress to honeycombing.
What CT findings suggest active lung disease in tuberculosis?
Cavitation
Consolidation
Ground glass opacities
Centrilobular opacities
What is required to determine disease inactivity on plain chest radiograph in tuberculosis?
Radiographic stability 6 months apart
What lung pathologies is the reverse halo sign associated with?
Mainly associated with COP.
Can also present in:
Vasculitis
Infarct
Sarcoidosis
Invasive fungal infection
And many other pathologies
What lung pathologies is the halo sign associated with?
Mainly associated with angioinvasive fungal infection (aspergillosis).
Other pathologies:
Other fungi Septic emboli TB/MAI Primary neoplasm/metastases COP/CEP Wegener HP
What is the anatomic boundary used to differentiate right from left paratracheal lymphadenopathy?
The left lateral wall of the trachea seperates left from right
In esophageal carcinoma, what is the determining factor when assessing the N staging of a tumor?
The number of involved lymph node stations determines N
