Elementary Lesions
Elementary Lesions
Micronodulation
Characteristics
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Focal rounded opacities < 3 mm presenting the following characteristics:
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Attenuation: ground glass opacity or tissular or even calcified
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Borders: blurry to clear
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Diagnostic Orientation
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The location of micronodulations helps guide the diagnosis:
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within the lungs
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within the secondary pulmonary lobule: key to diagnosis
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The CT scans helps categorise diffuse micronodulations based on three types of lobular distribution, thereby significantly reducing the differential diagnosis:
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random micronodulation
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centrilobular micronodulation
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centrilobular micronodulation
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1. Micronodulation, perilymphatic distribution
![perilpaticdistribution](/dk/hrct/sites/default/files/2022-04/perilymphatic%20distribution%402x.jpg)
- Coal workers’ pneumoconiosis.
- Extensive micronodulation with a perilymphatic distribution. Micronodules have an apical and posterior predominance.
2. Micronodulation
![micronodulation](/dk/hrct/sites/default/files/2022-04/Micronodulation%402x.jpg)
Centrilobular and perilymphatic micronodulation.
3. Micronodulation, centrilobular distribution
![centraldistribution](/dk/hrct/sites/default/files/2022-04/centrilobulardistribution%402x.jpg)
Micronodulation in the ventral segment of the right upper lobe sparing the subpleural part of the lung.