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4 Abnormal Lung Patterns |
Fig. 4.1 Example of a parenchymal mass. This well marinated, rounded opacity also displays the hilar overlay sign in that the hilar vessels can be seen through the mass
pleura; that may make the process resemble a mass (well-defined border, for example). Masses are usually rounded or ovoid.
See Fig. 4.1 for an example CXR with a mass in the right hilum. This ended up being a carcinoid.
Mass Considerations
Two considerations to think about when identifying a mass are the size of the mass as compared to normal vasculature and the shape of the mass.
Size
As previously mentioned, vessels in the lungs may appear as small nodules. These are important to differentiate from vessels. Vessels on-end should be the same size as similarly distributed vessels in profile: i.e., expected size/compared size.
Mass Characteristics
There are a few clues to narrowing down the mass differential. These include size, shape, margins, number, and distribution [2]. Many masses seen on CXR end up being evaluated CT [3].
Mass
Fig. 4.2 Benign calcification patterns (Image created by USUHS ETI Support Office)
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Diffuse |
Central |
Popcorn |
Laminar, |
Concentric |
Fig. 4.3 Indeterminate (potentially malignant) calcification patterns (Image created by USUHS ETI Support Office)
Stippled |
Eccentric |
Calcification Distribution in Masses
Calcifications are commonly visible in CXRs of Solitary Pulmonary Nodules (SPNs).