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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