Lecture 2.1 9/26/24

Question 1

What are the general characteristics of lung radiographs?

Answer 1

-normal lung is radiolucent
-most pulmonary diseases increase pulmonary opacity
-decreases in pulmonary opacity can occur with decreased vascularity or cavitary lesions
-lesions can be focal or diffuse/generalized

Question 2

What are the characteristics of a bronchial pattern?

Answer 2

-increased visibility, conspicuity, and thickening of bronchial walls
-doughnut and tramline appearance
-seen with lower airway disease
-associated with infectious, parasitic or allergic etiology

Question 3

What are the characteristics of a structured interstitial pattern?

Answer 3

-can occur with a single mass or multiple nodules
-can see “snowstorm lungs” when there are too many nodules to count

Question 4

What is the main differential for an interstitial pattern with a single mass?

Answer 4

primary neoplasia

Question 5

What are the differentials for an interstitial pattern with multiple nodules?

Answer 5

-metastatic neoplasia
-fungal disease

Question 6

What is the main differential for an interstitial pattern with “snowstorm lung?”

Answer 6

fungal disease

Question 7

What are the characteristics of an unstructured interstitial pattern?

Answer 7

-lung is diffusely increased in opacity
-vessels remain visible

Question 8

What are the differential diagnoses for an unstructured interstitial pattern?

Answer 8

-pulmonary edema
-interstitial hemorrhage
-interstitial pneumonia
-pulmonary fibrosis
-lymphoma
-early granulomatous/fungal disease
-normal variant

Question 9

What are the characteristics of an alveolar pattern?

Answer 9

-increased pulmonary opacity
-vessels cannot be identified
-caused by decreased volume of air in the lungs

Question 10

What can lead to decreased air in the lungs and an alveolar pattern?

Answer 10

-collapsed lung
-lung is filled with substance other than air

Question 11

What is the “tree in the fog” sign?

Answer 11

presence of an air bronchogram that indicates an alveolar pattern

Question 12

What are the important caveats of an alveolar pattern?

Answer 12

-not possible to determine the kind of fluid/cells that underlie the increased density on radiographs
-location and distribution of changes/abnormalities can make an accurate diagnosis possible

Question 13

What are the typical causes of an alveolar pattern?

Answer 13

-trauma
-hemorrhage
-heart failure/pulmonary edema
-pneumonia
-collapsed lung

Question 14

How is the significance of lung patterns ranked?

Answer 14

always significant: structured interstitial and alveolar
typically significant: bronchial
sometimes significant: unstructured interstitial