• TCV Finding: Air Bronchogram
  • Etymology
    • Derived from the Greek words “aer” meaning air and “bronchos” meaning windpipe or airway, combined with “gramma,” meaning a written or visual representation.
  • AKA and Abbreviation
    • Commonly referred to as “air bronchograms.”
  • What is it?
    • An air bronchogram refers to the radiological phenomenon where air-filled bronchi are made visible by the surrounding alveoli, which are opacified due to pathology such as fluid, pus, or cells.

It is Black and White

When Things are Different,
Especially When They Are Total Opposites –
They Each Become Much Clearer

CT Scan of Air Bronchograms
Secondary to Bacterial Pneumonia
in the Lingula

• • Principles
    • Visible bronchi containing air
    • Surrounding opacified alveoli (consolidation)
    • Or empty alveoli (atelectasis)
    • affected by pathological processes.
    • Character
      • Sharp contrast between air-filled bronchi and surrounding dense parenchyma. This contrast highlights the bronchial tree as a negative radiographic shadow. The alveoli can be filled with pus, blood, aspirated material, inflammatory cells, or malignant cells, contributing to the opacification and formation of air bronchograms.
  • Applied Anatomy to Radiology
    • CXR
      • Appears as air-filled branching structures within opacified areas, most commonly associated with lung consolidation.
      • Indicative of alveolar processes rather than interstitial abnormalities.
    • CT
      • Air bronchograms are clearly visualized due to the high contrast between air-filled bronchi and surrounding opacified lung parenchyma.
      • Parts:
        • Air bronchograms involve the bronchi, which remain air-filled, and the surrounding alveoli, which become opacified due to fluid, cells, or other pathological material.
      • Size:
        • The size of visible air bronchograms depends on the generation of bronchi involved. Larger bronchi produce more prominent air bronchograms, while smaller subsegmental bronchi contribute to finer branching patterns.
        • Normally, the mainstem and segmental bronchi are visible because the air in these airways is surrounded by the soft tissue density of the bronchial walls. Subsegmental airways and distal branches become visible when the surrounding alveoli are filled with soft tissue density due to fluid, cells, or other pathological material, creating the contrast necessary to visualize these smaller airways as air bronchograms.
      • Shape:
        • Typically tubular or branching structures that mirror the bronchial anatomy. The pattern may appear linear, tree-like, or occasionally nodular depending on the pathology.
        • The angles of the airways help differentiate between atelectasis and consolidation. In atelectasis, the angles of the airways become more acute due to lung volume loss, while in consolidation, they maintain their normal anatomical angles.
      • Position:
        • Found in areas of lung consolidation or other alveolar opacities. They follow the anatomical distribution of bronchi within the affected lung segment or lobe.
      • Character:
        • Sharp contrast between air-filled bronchi and surrounding dense parenchyma. This contrast highlights the bronchial tree as a negative radiographic shadow. The alveoli can be filled with pus, blood, aspirated material, inflammatory cells, malignant cells, which contrasts with the air-filled bronchi, resulting in visible air bronchograms. Alternatively the alveoli  may be filled with “nothing,” as in atelectasis, where the surrounding soft tissue density of the collapsed lung results in visible air bronchograms
      • Time:
        • Visible in acute and chronic conditions, with dynamic changes over time depending on the progression or resolution of the underlying pathology. Air bronchograms associated with CHF can resolve within 24-48 hours after appropriate diuretic therapy, as pulmonary edema clears.  Hemorrhage typically resolves rapidly, often within 48-72 hours, due to reabsorption and clearance of blood. Bacterial infections, following successful antibiotic therapy, should resolve within approximately 6 weeks, though this can vary based on the organism and patient factors. Other causes, such as malignancy, may persist until the underlying condition is treated.
    • Ultrasound
      • Dynamic air bronchograms can be seen in real-time, particularly in cases of pneumonia, with moving air bubbles visible within fluid-filled alveoli.
  • Pathological Implications
    • Diseases associated with air bronchograms include:
      • Infectious processes: Pneumonia, tuberculosis.
      • Non-infectious conditions: Pulmonary edema, acute respiratory distress syndrome (ARDS).
      • Neoplastic causes: Malignant cellular infiltration such as in adenocarcinoma with lepidic growth pattern
      • Atelectasis: The surrounding soft tissue density of the collapsed lung results in visible air bronchograms
  • Key Points and Pearls
    • Air bronchograms are hallmark features of alveolar processes rather than interstitial disease.
    • The presence of air bronchograms suggests patent airways surrounded by fluid-filled or consolidated alveoli.
    • Dynamic air bronchograms on ultrasound help differentiate pneumonia from atelectasis, where air movement is typically absent.

Multifocal Pneumonia with
Air Bronchograms Exemplified in the
Right Lower Lung Zone in the
Middle Lobe on CXR

On Closer Inspection
Prominent Air Bronchograms in the
Left Lower Lobe (behind the heart)
Also Upper Lobes (less obvious)

CT Scan of Air Bronchograms
Secondary to Bacterial Pneumonia in the Lingula

Chronic Eosinophillic Pneumonia
Upper Lobe Peripheral Consolidations with
Air Bronchograms

Lobar

Segmental

Subsegmental

Radiopaedia

“Air bronchogram refers to the phenomenon of air-filled bronchi (dark) being made visible by the opacification of surrounding alveoli (grey/white). It is almost always caused by a pathologic airspace/alveolar process, in which something other than air fills the alveoli. Air bronchograms will not be visible if the bronchi themselves are opacified (e.g. by fluid) and thus indicate patent proximal airways.

Air bronchograms can be seen with several processes:

• pulmonary consolidation
• pulmonary edema: especially with alveolar edema ³
• non-obstructive atelectasis
• severe interstitial lung disease
• neoplasms: bronchioloalveolar carcinoma; pulmonary lymphoma
• pulmonary infarct
• pulmonary hemorrhage
• normal expiration

Air bronchograms that persist for weeks despite appropriate antimicrobial therapy should raise the suspicion of a neoplastic process. CT may be planned in such cases.”

Parallels with Human Endeavors

Opposites Like Black and White

Things often become clearer when they differ from their surroundings, and they become crystal clear when they are in stark contrast or opposition. This concept mirrors how air bronchograms emerge in radiology when air-filled bronchi stand out against the opaque background of diseased alveoli. Similarly, in life, contrasts—such as good and bad, black and white, heaven and hell—help us define and understand the essence of each side.

Art and Sculpture

Artists often use stark contrasts to convey profound themes or emotions. Michelangelo’s “Last Judgment” in the Sistine Chapel vividly portrays the extremes of heaven and hell, with bright, celestial imagery juxtaposed against dark, chaotic depictions of damnation.

Heaven and Hell Michelangelo 

Michelangelo The Last Judgment Sistine Chapel.
Heaven and HellCaravaggio’s works, such as “The Calling of Saint Matthew,” are renowned for their dramatic use of chiaroscuro (light and dark contrast) to highlight the tension between divine and earthly realms, creating a visual metaphor for moral and spiritual clarity.

Enlightened St Matthew and Darkened Background 

 

William Blake’s “The Great Red Dragon and the Woman Clothed in Sun” uses bold contrasts to depict spiritual struggle and cosmic opposition.

 

Francisco Goya’s “The Third of May 1808” starkly portrays light and dark to emphasize human suffering and the brutality of war.

 

Edvard Munch’s “The Scream”: This iconic piece contrasts vivid colors and dark elements to capture despair and existential dread.

 

Biblical and Religious

• • • • • The Ten Commandments (Exodus 20:1-17): Explicitly define moral opposites such as “You shall not murder” versus the value of preserving life and “Honor your father and mother” versus dishonor or neglect.

        • 

Genesis 1:4: “God saw that the light was good, and He separated the light from the darkness.” Symbolic of establishing order and the distinction between good (light) and evil (darkness).

• • • • • Light and Darkness Day and Night
          Ashley Davidoff art
          TheCommonVein.net

Matthew 7:13-14: “Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it. But small is the gate and narrow the road that leads to life, and only a few find it.”

The Broad and Narrow Path

Revelation 21:8: “But the cowardly, the unbelieving, the vile, the murderers, the sexually immoral, those who practice magic arts, the idolaters, and all liars—they will be consigned to the fiery lake of burning sulfur.” Contrasts the rewards of heaven with the punishments of hell.

Hinduism :

Quotes by Famous People

“Without contraries is no progression. Attraction and repulsion, reason and energy, love and hate, are necessary to human existence.”
– William Blake

“Opposites are not contradictory but complementary.”
– Niels Bohr

“Life is about balance. The good and the bad. The highs and the lows. The piña and the colada.”
– Ellen DeGeneres

“The best and most beautiful things in the world cannot be seen or even touched—they must be felt with the heart. And perhaps that’s why opposites attract.”
– Helen Keller

“Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that.”
– Martin Luther King Jr.

“Every sweet has its sour; every evil its good.”
– Ralph Waldo Emerson

 Literature

“Candide” by Voltaire (1759)

This satirical novella contrasts optimism (positive) and pessimism (negative) through the misadventures of Candide, exposing the absurdities of human suffering and the search for meaning.

Key Quote: “All is for the best, in the best of all possible worlds.”

“Frankenstein” by Mary Shelley (1818)

The duality of creation (positive) and destruction (negative) is explored through Victor Frankenstein’s quest to animate life and the consequences of his ambition.

Dr. Jekyll and Mr. Hyde” by Robert Louis Stevenson (1886)

The novella explores the duality of human nature through the contrasting personas of Dr. Jekyll (good) and Mr. Hyde (evil).

Key Quote: “Man is not truly one, but truly two.”

“Crime and Punishment” by Fyodor Dostoevsky (1866)

This novel examines guilt and redemption, contrasting moral degradation with the hope of spiritual rebirth.

Key Quote: “Pain and suffering are always inevitable for a large intelligence and a deep heart.”

“Wuthering Heights” by Emily Brontë (1847)

The wild and passionate Heathcliff is set in contrast to the more refined and orderly Linton family, embodying elemental opposites of nature versus culture.

Key Quote: “Whatever our souls are made of, his and mine are the same.”

Key Quote: “Beware; for I am fearless, and therefore powerful.”

 

Links and References

Fleischner Society

air bronchogram

Radiographs and CT scans.—An air bronchogram is a pattern of air-filled (low-attenuation) bronchi on a background of opaque (high-attenuation) airless lung (^,Fig 2). The sign implies (a) patency of proximal airways and (b) evacuation of alveolar air by means of absorption (atelectasis) or replacement (eg, pneumonia) or a combination of these processes. In rare cases, the displacement of air is the result of marked interstitial expansion (eg, lymphoma) (^,8).