3. Secondary lobule
• It is the basic anatomic unit of pulmonary
structure and function.
•
It is the smallest lung unit that is surrounded
by connective tissue septa.
4. 1-2 cm and is made up of 5-
15 pulmonary acini
Supplied by a small
bronchiole (terminal
bronchiole) in the center,
that is parallelled by the
centrilobular artery.
Pulmonary veins and
lymphatics run in the
periphery
Two lymphatic systems:
central network
peripheral network
20. Septal thickening and ground-glass opacity
with a gravitational distribution in a patient
with cardiogenic pulmonary edema.
21. Notice the nodules along the fissures indicating a perilymphatic
distribution (red arrows).
The majority of nodules located along the bronchovascular bundle (yellow
arrow).
23. Parenchymal bands
Non tapering reticular opacity,1-3 mm in tickness
and 2 to 5 cm in length
Often peripheral and contacts the pleural surface
Represent contiguous thickened interlobulsr
septa,peribronchovascular fibrosis,scars or
atelectasis
26. Subpleural line
Curvilinear opacity,few mm or les in
thickness,prallelling the pleura and less than 1 cm
from the pleural surface.
Represent fibrosis / localized alveolar collapse /
atelectasis.
Commonly seen in asbestosis
27.
28. Size, Distribution, Appearance
Nodules and Nodular Opacities
28
SizeSize
Small Nodules: <10 mm Micro - <3 mmSmall Nodules: <10 mm Micro - <3 mm
Large Nodules: >10 mm Masses - >3 cmsLarge Nodules: >10 mm Masses - >3 cms
AppearanceAppearance
Interstitial opacity:
Well-defined, homogenous,
Soft-tissue density
Obscures the edges of vessels or adjacent structure
Interstitial opacity:
Well-defined, homogenous,
Soft-tissue density
Obscures the edges of vessels or adjacent structure
Air space:
Ill-defined, inhomogeneous.
Less dense than adjacent vessel – GGO
small nodule is difficult to identify
Air space:
Ill-defined, inhomogeneous.
Less dense than adjacent vessel – GGO
small nodule is difficult to identify
36. Centrilobular nodules
5 to 10mm away from the pleural surface
Evenly spaced
Associated with pumonary artery branches
If air filled centrilobular bronchiole----lucency
within the nodule
44. Tree-in-bud
44
Centrilobular nodules m/b further characterized by presence or
absence of ‘‘tree-in-bud.’’
Tree-in-bud -- Impaction of centrilobular bronchus with mucous,
pus, or fluid, resulting in dilation of the bronchus, with associated
peribronchiolar inflammation .
Dilated, impacted bronchi produce Y- or V-shaped structures
This finding is almost always seen with pulmonary infections.
67. HONEYCOMBING
67
Defined as - small cystic spaces with irregularly
thickened walls composed of fibrous tissue.
Predominate in the peripheral and subpleural lung
regions
Subpleural honeycomb cysts typically occur in several
contiguous layers. D/D- paraseptal emphysema in
which subpleural cysts usually occur in a single layer.
68. Honey combing
Air filled cystic spaces
Several mm to cms in diameter
Peripheral and subpleural
Definable walls,1 to 3 mm in thickness
Associated with findings of lung fibrosis
74. HRCT Appearances LAM
Numerous thin-walled cysts, surrounded by normal
parenchyma.
Round in shape and more or less uniform.
Mediastinal or hilar adenopathy .
Chylous Pleural effusions (40%).
Recurrent pneumothorax (40%)
75. Multiple thin-walled cysts of roughly uniform size.
Unlike LCH, the cysts in LAM tend to be rounded
and uniformly distributed throughout the
parenchyma with no regional sparing.
There is a conspicuous absence of nodules.
81. Centrilobular emphysema
81
Manifests as multiple small areas of low attenuation without a
perceptible wall, producing a punched-out appearance.
Often the centrilobular artery is visible within the centre of
these lucencies.
82. Centrilobular emphysema due to smoking. The periphery of the
lung is spared (blue arrows). Centrilobular artery (yellow arrows) is
seen in the center of the hypodense area.
83. Panlobular emphysema
Affects the whole secondary lobule
Lower lobe predominance
In alpha-1-antitrypsin deficiency, but
also seen in smokers with advanced
emphysema
90. Bullae and blebs
Bulla : sharply demarcated area of emphysema
measuring 1cm or more in diameter with a wall that
is < 1 mm.
Bleb: focal thin walled lucency contigous with pleura
usually at lung apex
91.
92. Pneumatocoele
Thin walled gas filled space within the lung,usually
assosciated with pneumonia
Appearance similar to cyst or bulla and cannot be
differentiated
97. • localized bronchial dilatation. (signet-ring sign)
bronchial wall thickening
lack of normal tapering with visibility of airways in the
peripheral lung
mucus retention in the broncial lumen
98. ABPA: glove-finger shadow due to mucoid impaction in central
bronchiectasis in a patient with asthma.
99. Signet-Ring Sign
A signet-ring sign represents an axial cut of a dilated bronchus
(ring) with its accompanying small artery (signet).
105. Mosaic perfusion and attenuation
Due to airway disease
Due to vascular disease
Infiltrative process adjacent to normal lung
106.
107.
108. Inhomogenous lung opacity
Decreased vessel size Uniform sized vessels
Some regions too lucent Some regions too dense
No reticulation Associated reticulation,
No Nodules Nodules
Mosaic perfusion Ground glass opacity
109. Inhomogenous lung opacity
Decreased size of vessels uniform sized vessels
(suspect mosaic perfusion) (suspect GGO)
No air trapping air trapping no air
trapping
Vascular disease obstructive disease infiltrative
disease
Chronic PE small airways disease GGO DD’s
large airways disease
110. Air trapping on expiration
Diagnosis of air trapping in obstructive lung disease
Diagnosis of airway diseases with normal inspiratory
scan
Distinguishing mosaic perfusion from GGO
Allowing the diagnosis of mixed infiltrative and
obstructive diseases
114. Mosaic perfusion
Pulmonary hypertension Abnormal airways
Large areas of lucency Lobular lucencies
Vascular disease Obstructive disease
Chronic PE small airways disease
lareg airways disease
Notes de l'éditeur
Unit of lung (0.5-3 cm)
Irregularly polyhedral متعدد السطوح
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma
Unit of lung (0.5-3 cm)
Irregularly polyhedral متعدد السطوح
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma
Unit of lung (0.5-3 cm)
Irregularly polyhedral متعدد السطوح
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma
Unit of lung (0.5-3 cm)
Irregularly polyhedral متعدد السطوح
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma
Unit of lung (0.5-3 cm)
Irregularly polyhedral متعدد السطوح
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma
Unit of lung (0.5-3 cm)
Irregularly polyhedral متعدد السطوح
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma
Unit of lung (1 cm to 1 inch)
Irregularly polyhedral
Supplied by a group of terminal bronchioles and accompanying pulmonary arterioles surrounded by lymph vessels
Demarcated by “interlobular septa”
pulmonary veins
pulmonary lymphatics
connective tissue stroma