Elementary Lesions

Elementary Lesions

Micronodulation

Characteristics

  • Focal rounded opacities < 3 mm presenting the following characteristics:

    • Attenuation: ground glass opacity or tissular or even calcified

    • Borders: blurry to clear

Diagnostic Orientation

  • The location of micronodulations helps guide the diagnosis:

    • within the lungs

    • within the secondary pulmonary lobule: key to diagnosis

  • The CT scans helps categorise diffuse micronodulations based on three types of lobular distribution, thereby significantly reducing the differential diagnosis:

    • random micronodulation

    • centrilobular micronodulation

    • centrilobular micronodulation

1. Micronodulation, perilymphatic distribution

perilpaticdistribution
  • Coal workers’ pneumoconiosis.
  • Extensive micronodulation with a perilymphatic distribution. Micronodules have an apical and posterior predominance.

2. Micronodulation

micronodulation

Centrilobular and perilymphatic micronodulation.

3. Micronodulation, centrilobular distribution

centraldistribution

Micronodulation in the ventral segment of the right upper lobe sparing the subpleural part of the lung.