collapse consolidation
DESCRIPTION
chest radiology of collapse and consolidation on plain radiographyTRANSCRIPT
Collapse &
Consolidation
Collapse / Atelectasis
Lung collapse refers to the complete or partial loss of
normal aeration and associated loss of volume(akin to
deflating a balloon).
Consolidation
The term consolidation refers to the
displacement of the air in the alveoli, smaller
bronchi, and bronchioles, by exudate or
edematous fluid.
Important Features
Collapse & consolidation can occur independently or
together.
Collapse can be partial or complete.
Extent of appearance due to collapse or consolidation or
both is often not clear.
Association/ Broad Aspect
Consolidation Without volume loss:
---Pneumonia, Pulmonary edema,
Hemorrhage.
Consolidation With volume loss:
---“Atelectasis” or “Collapse”
Consolidation With volume loss
Consolidation Without volume loss
Types of collapse
Obstructive
Non- Obstructive
Causes of Obstructive collapse Blockage of an airway…
Causes:
1). Bronchogenic carcinoma
2). Bronchial carcinoid
3). Metastases to the bronchi
4). Lymphoma
5). Tuberculosis
6). Left atrial enlargement from mitral stenosis
7). Foreign body obstruction
8). Main stem bronchus intubation
Causes of Non-Obstructive collapse
Loss of contact between the parietal and visceral
pleura,
Parenchymal compression,
Loss of surfactant,
Replacement of lung tissue by scarring or
infiltrative disease.
Mechanism of Atelectasis
Resorption
Relaxation
Adhesive
Cicatrization
Resorption Collapse
Air retained distal to occlusion is resorbed from the
non ventilated alveoli in obstructive type of
atelectasis. Over time, affected area becomes
totally airless causing alveolar collapse.
Relaxation Collapse
Contact between parietal & visceral pleurae is
eliminated.
Lung tends to retract towards its hilum when air or
fluid collects in the pleural space.
1). Pleural effusion
2). Pneumothorax
3). Hydrothorax, hemothorax
4). Diaphragmatic hernia
5). Pleural masses (including metastases and
mesothelioma)
Adhesive Collapse
Induced by surfactant dysfunction.
Decreased production or inactivation of surfactant leads to alveolar instability and collapse although central airways remain patent.
Respiratory distress syndrome of premature infants, ARDS, acute radiation pneumonitis, PE and lung contusion.
Cicatrisation Collapse
Diminution of volume as a sequel of severe parenchymal scarring.
Etiologies include:
granulomatous disease
late sequelae of TB
necrotizing pneumonia
radiation
pneumoconiosis
Collagen vascular diseases (e.g. scleroderma, rheumatoid lung)
Signs Of Collapse
Lobar:
Shift of fissures
Crowding of vessels (increased opacity)
Extra lobar:
Hemi diaphragm elevation.(Juxtaphrenic peak sign)
Mediastinal shift towards side of collapse
Hilar shift and distortion(Katan’s triangle sign)
Compensatory contra-lateral hyperinflation
Rib approximation.
Obscuring of structures adjacent to collapsed lung, such as the diaphragm, heart, or pulmonary vessels.
Causes Of Consolidation
Acute pneumonia.
Chronic Pneumonia:
------ Bacterial.
------ Lipoid.
------ Aspiration.
Pulmonary Hemorrhage.
Bronchoalveolar carcinoma.
Alveolar proteinosis.
Radiological Features of
Consolidation Increased density.
Acinar shadow.
Silhouette sign.
Air bronchogram.
Distribution of consolidation can vary widely.
Can be described as “patchy”, “homogenous”, or
generalized”.
Can be described as focal or by the lobe or segment
of lobe affected.
The left lung has •1 fissure
•2 lobes
The left lung has
•1 fissure
•2 lobes
The right lung has
The right lung has
•2 fissures
•3 lobes
RUL Anatomy
RUL Consolidation
RUL consolidation will be seen as
an increased opacity within the
shaded area. Opacity may be
sharply bordered by the horizontal
fissure
Some loss of outline of upper
right heart border may be apparent
•Dense opacity seen
above the horizontal
fissure.
•Air-bronchogram
line
•The lower border of
the consolidation is
sharply delinated by
the horizontal
fissure,suggesting
ant segment
involvement.
Dense opacity in the RUL
sharply bordered by the
horizontal and oblique
fissures suggesting
involvement of the anterior
and posterior segments of
the RUL
RUL Collapse
RUL collapses toward ant, sup &
medial portion of chest.
Medial collapse may mimic a right
paratracheal mass
Lateral collapse lead to peripheral
mass-like opacity mimicking a
loculated pleural effusion.
Right middle & lower lobes hyper
expand superiorly & medially.
Signs Of RUL Collapse
S Sign of Golden.
Juxta-phrenic peak sign.
S Sign of Golden - Refers to reverse
"S" shape of minor fissure in RUL
collapse due to a central obstructing
mass. Sup portion of "S" form displaced
minor fissure, while inf. portion results
from mass itself.
Juxtaphrenic
Peak - triangular
opacity
sometimes seen
over medial
portion of
diaphragm. Also
seen in cases of
RUL lobectomy.
Results from
superior
displacement of
inferior accessory
RML Anatomy
RML Consolidation
Seen as an area of
increased opacity in the
shaded area
•Loss of the definition of the
right heart border is often
seen
RML consolidation is
characteristically seen as a
wedge opacity in the lateral
view
•May be sharply bordered by the
horizontal and oblique fissures
RML Collapse
RML collapse relatively easy to identify on lateral view, appearing as a triangular opacity in anterior aspect of chest, overlying cardiac shadow.
On frontal radiographs findings are subtle.
--- Normal horizontal fissure no longer visible (as it rotates down)
--- Blurring of right heart border.
RML Collapse Syndrome
Frequently non-obstructive
Accompanied by scarring and bronchiectasis
Often found in elderly women
Chronic cough is most common symptom.
Hemoptysis, chest pain and dyspnoea are also
reported .
Associated with blurring of right heart border.
RLL Anatomy
Right lower lobe comprises of 5 pulmonary
segments. Its a large lobe & will provide varying
patterns of consolidation depending on
segments involved.
Note that consolidation of the
apical segment will not result
in loss of the diaphragmatic
outline.
RLL Consolidation
•Loss of right hemi-diaphragm
•Dense opacity in RLL
•Some loss of right heart
border
•Increased triangular opacity
within the RLL
•Commonly seen with loss of the
right hemi-diaphragm
RLL Collapse Collapse is in post, med & inf
direction.
Major fissure swings down
&backward.
Hilum is displaced inferiorly.
Hemidiaphragm is elevated.
On PA view a triangular opacity
adjacent to spine with base on
hemidiaphragm.
On lateral view there is
increased opacity over lower
thoracic vertebrae .
RLL Collapse
Another indirect sign is vascular nodular sign, due to
compensatory hyperinflation of upper lobe.
Radiographically seen as "hair-pin" turning of vessels &
"too-many nodules" along cardiac margin, which are end-
on vessels.
RLL Collapse
LUL Anatomy
On left there is no middle lobe; Anatomical equivalent region corresponding to
right middle lobe is the lingula, & like RML, is also composed of two
segments. Unlike their counterparts on the right however, the segments are
stacked one on top of another, rather than side. Note that upper lobe
pathology can appear very low on chest X-ray image. The upper lobe is
anterior lobe as much as it is upper lobe.
LUL Consolidation
Opacity left hemi-thorax
•Air-bronchogram lines
•Some loss of left heart
border.
Characteristically not a
dense opacity of the PA
view
Opacity Can be sharply
bordered by the oblique
fissure
•Does not involve the
diaphragm
LUL Collapse
Left major fissure is displaced
ant, roughly parallel to ant
chest wall.
On PA view it produces a
faint, hazy opacity in left upper
hemithorax, that can be
mistaken for pleural
thickening.
LUL Collapse
Left cardiac contour is frequently obscured by lingula.
Hyper-expanded left lower lobe occupies most of left
hemithorax, with its superior segment occupying apex,
mimicking an aerated upper lobe.
Left hilar structures are retracted cephalad.
LUL Collapse
LUL Collapse
Luftsichel, an indirect sign of LUL collapse.
Its Crescent of aerated lower lobe.
This represent an incomplete major fissure pulled
forward by atelectatic upper lobe, interposed between
atelectasis & aortic arch.
Left lower lobe basilar segmental arteries are elevated
and clearly visible in retrocardiac location.
Note the
increased
opacification of
left upper lung
field with
elevation of left
hemi-
diaphragm.
In addition,
there is lucency
adjacent to the
aorta.
This is the
Luftsichel sign,
representing an
over-expanded
right lower
lobe.
LLL Anatomy
Left lower lobe is similar in structure to Right lower lobe except that it has two
segments combined - as the anterior and medial basal segments share a
common bronchial supply, these two segments are characteristically
combined, forming an anterior medial basal segment.
LLL Consolidation
• Look Behind the Heart Shadow
One of the more subtle appearances of
consolidation can be seen when the left heart
shadow appears abnormally dense.
•
Obliteration of the Descending Aorta
"The descending aorta indents the superior and
posterior basal segments of the LLL, and its lateral
margin is therefore obliterated by lesions in these
segments"
Appears as an area of increased
opacity within the LLL
•Some loss of the hemi-diaphragm
medially is seen
•increased density behind left
heart shadow
•Increased opacity within the
LLL
•Loss of the normal darkening
of the thoracic spine inferiorly
•some loss of the left hemi-
diaphragm posteriorly
May be sharply delineated by
oblique fissure
LLL Collapse
Left major fissure can parallel left cardiac
border & the completely atelectatic lobe can
mimic a left paraspinal mass.
Increased retrocardiac opacity with
obscuring of left lower lobe vessels & left
hemidiaphragm.
Caudad displacement of left hilum.
Mediastinal shift can lead to partial
obliteration of the aortic arch (the top of the
knob sign)
This image shows complete opacification of most of left upper lobe. When bronchi
remain aerated, they are seen as branching lucencies called air-bronchograms. This
image represents infectious pneumonia, limited by major fissure, resulting in a sharp
border.
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