Download Radiological Signs of Chest Diseases

Air Bronchogram Sign
Branching, linear, tubular lucency
representing a bronchus or
bronchiole passing through airless
lung parenchyma .
This sign indicates that the
underlying opacity must be
parenchymal rather than pleural or
mediastinal in location.
DD:
Pneumonia
lymphoma
bronchoalveolar cell carcinoma.
 Congenital surfactant protein B deficiency-alveolar
proteinosis. A newborn full-term girl with severe respiratory
distress. The scout film reveals diffuse hazy opacification with
air bronchogram
 Note air bronchogram (arrow
Bulging Fissure Sign
Consolidation spreading rapidly, causing lobar expansion and
bulging of the adjacent fissure inferiorly .
Historically Klebsiella pneumoniae involving the right upper lobe .
Friedlander pneumonia: A form of pneumonia caused by infection with Klebsiella
Continuous Diaphragm Sign
Continuous lucency outlining the
base of the heart, representing
pneumomediastinum .
Air in the mediastinum tracks
extrapleurally, between the heart
and diaphragm .
Pneumopericardium can have a
similar appearance but will show air
circumferentially outlining the
heart.
PA chest radiograph of a patient with acute respiratory distress syndrome shows a ring
of lucency around the right pulmonary artery (arrows), signifying pneumomediastinum.
B: CT confirms air surrounding both pulmonary arteries (arrows).
CT angiogram Sign
Identification of vessels within an
airless portion of lung on contrastenhanced CT .
The vessels are prominently seen
against a background of lowattenuation material .
Associated with:
bronchoalveolar cell carcinoma
lymphoma
infectious pneumonias.
Deep Sulcus Sign
This sign refers to a deep
collection of intrapleural air
(pneumothorax) in the
costophrenic sulcus as seen
on the supine chest
radiograph .
Deep sulcus sign. Anteroposterior (AP) supine chest radiograph shows bilateral
neumothoraces (intrapleural air) as a result of barotrauma from mechanical ventilation.
On the right, the visceral pleura is separated from the parietal pleura by intrapleural air
long the apicolateral chest wall (larger arrows). On the left, the intrapleural air is collecting
t the lung base, expanding the costophrenic sulcus (smaller arrows). The stiff lungs do
ot collapse completely in this patient with acute respiratory distress syndrome
 Deep sulcus sign. AP shows
a right basilar
pneumothorax (arrow),
which expands the
costophrenic sulcus,
creating a tonguelike
extension of air that
continues inferiorly along
the right lateral chest wall.
Note bilateral lung
contusion,
pneumomediastinum, and
bilateral subcutaneous
emphysema.
Fallen Lung Sign
This sign refers to the appearance of
the collapsed lung occurring with a
fractured bronchus .
The bronchial fracture results in the
lung to fall away from the hilum,
either inferiorly and laterally in an
upright patient or posteriorly, as
seen on CT in a supine patient.
DD:
Pneumothorax causes a lung to
collapse inward toward the hilum.
Spine sign. A: PA chest radiograph of a patient with left lower lobe pneumonia
shows abnormal opacity in the left lower lung. B: Lateral view shows this opacity
projected over the lower spine (arrows). Normally, the spine becomes progressively
more lucent from the top to the bottom on the lateral view. The presence of increased
opacity over the lower spine is an indication of a lower lobe process, typically
pneumonia, and is called the spine sign.
Flat waist Sign
This sign refers to flattening of the contours of the aortic knob and adjacent main
pulmonary artery .
It is seen in severe collapse of the left lower lobe and is caused by leftward
displacement and rotation of the heart
Finger in Glove Sign
In allergic bronchopulmonary aspergillosis.
The impacted bronchi appear radiographically as opacities with distinctive
shapes.
Golden S sign:
When a lobe collapses around a large central mass, the peripheral lung collapses
and the central portion of lung is prevented from collapsing by the presence of the
mass.
The relevant fissure is concave toward the lung peripherally but convex centrally,
and the shape of the fissure resembles an S or a reverse S .
Halo Sign
CT shows nodular consolidation associated with a halo of ground-glass opacity
(GGO) in both apices resulting from invasive pulmonary aspergillosis.
This halo represents hemorrhage.
When seen in leukemic patients, is highly suggestive of the diagnosis of invasive
pulmonary aspergillosis.
Hampton Hump Sign
Pulmonary infarction secondary to pulmonary embolism produces
an abnormal area of opacification on the chest radiograph, which is
always in contact with the pleural surface.
Juxtaphrenic Peak Sign
This sign refers to a small triangular shadow that obscures the dome of the
diaphragm secondary to upper lobe atelectasis . The shadow is caused by traction
on the lower end of the major fissure, the inferior accessory fissure, or the inferior
pulmonary ligament.
Luftsischel Sign
In left upper lobe collapse, the superior segment of the left lower lobe, which is
positioned between the aortic arch and the collapsed left upper lobe, is
hyperinflated. This aerated segment of left lower lobe is hyperlucent and shaped
like a sickle, where it outlines the aortic arch on the frontal chest radiograph.
This peri-aortic lucency has been termed the luftsichel sign, derived from the
German words luft (air) and sichel (sickle).
Westermark Sign
This sign refers to
oligemia of the lung
beyond an occluded
vessel in a patient with
pulmonary embolism
Interpretation Challenges:
Silhouette Effect
 Two structures of the same radiopacity in contact
– their margins cannot be identified
Lung Fields: Using Structures / Silhouettes
Silhouette / Structure
Contact with Lung
Upper right heart
border/ascending aorta
Anterior segment of RUL
Right heart border
RML (medial)
Upper left heart border
Anterior segment of LUL
Left heart border
Lingula (anterior)
Aortic knob
Apical portion of LUL
(posterior)
Anterior hemidiaphragms
Lower lobes (anterior)
Lung Fields: Using Structures / Silhouettes
Upper right heart
border /
ascending aorta
(anterior RUL)
Right heart border
(medial RML)
Anterior
hemidiaphragms
(anterior
lower lobes)
Aortic knob
(Apical portion
of LUL )
Upper left
heart border
(anterior
LUL)
Left heart
border
(lingula;
anterior)
Cancer - Tumor In Right Lung
Interpretation Challenges:
Silhouette Effect
Interpretation Challenges:
Silhouette Effect
the right lower lung, which partially obscures the right heart border (the silhouette sign),
ndicating a process involving the right middle lobe. B: Lateral view shows a triangular
opacity over the heart (arrows), confirming a right middle lobe process.
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