Lung Pattern

and Alessandra Cancellieri²

(1)

Department of Radiology, Bellaria Hospital, Bologna, Italy

(2)

Department of Pathology, Maggiore Hospital, Bologna, Italy

Radiology	Giorgia Dalpiaz
Pathology	Alessandra Cancellieri

Dark lung pattern	Definition	Page 234
Subset bronchiolar		Page 235
Subset vascular		Page 237
Tables		Page 238

Dark Lung Pattern

Definition

A dark lung pattern is present when variable portions of pulmonary parenchyma show reduced attenuation to the X‐rays, and then are darker than normal. The size and number of the vessels within the pathologic dark areas are smaller than in the non-pathologic white areas.

Unlike the cystic pattern, here the basic abnormality is not pure black, but rather a dark gray. The dark areas basically depend on a reduction of blood flow, either due to a reduced vascular flow (vascular dark lung) or to a hypoxic vasoconstriction from a bronchiolar disease (bronchiolar dark lung).

Mosaic oligoemia/perfusion

The non-pathologic “white” areas are also defined “pseudo-GGO”. When the “mosaic” is otherwise given by patchy areas of ground-glass opacity (GGO), size and number of the vessels within different areas should be equal.

The prevalent distribution of the signs together with the presence or absence air trapping and non-parenchymal signs may be helpful for the diagnosis of a specific disease (see the Tables at the end of this Chapter).

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Maffessanti M, Dalpiaz G (2011) Dark lung pattern. In: Leslie KO, Wick MR (eds) Practical pulmonary pathology. A diagnostic approach. Churchill Livingstone (Elsevier), Philadelphia