Nodules can be characterized by the following features:
1.
Localisation
2.
Density
3.
Calcification
4.
Shape
5.
Margin
•I.
Where is the nodule located?
The first step during the reading process is localisation of lesions; which side (left/right) and in which segment (1-10.) are they located? In this regard nodules may be parenchymal,
subpleural,
perifissural and proximal to a vessel.
(Fig.
1.)
•II.
Density
Lung nodules can be divided into solid,
part-solid and non-solid types.3 (Fig.
2.)
•III.
Calcification
Calcification can be a sign of benignity or malignity.
Homogenous,
central,
popcorn and lamellar types of calcification are generally regarded as benign,
while eccentric and stippled types are considered to be malignant.4 (Fig.
3.)
•IV.
Shape
Nodules can be round,
irregular,
lentiform or triangular in shape.
(Fig.
4.)
•V.
Edge
The edge of a nodule may be sharp,
spiculated,
lobulated or blurred.5 (Fig.
5.)
Asymptomatic individuals may show three major types of parenchymal change: emphysema,
interstitial lung disease and respiratory disease.
(Fig.
6.)
Interstitial lung diseases comprise respiratory bronchiolitis,
Langerhans cell histiocytosis,
and desquamative interstitial pneumonia.6 (Fig.
7.)
Emphysema can be divided into centrilobular,
panlobular and paraseptal forms,
and further subdivided into mild,
moderate and severe types.
(Fig.
8.)
Respiratory diseases can manifest in the form of air-trapping,
bronchial wall thickening or bronchiectasis.
(Fig.
9.)
Distinguishing mediastinal and hilar lymph nodes on an unenhanced study is limited,
while coronary artery calcification is easily observed.
A three-level scale is sufficient to describe coronary sclerosis.
(Fig.
10.,
11.,
12.)
Significant lesions in the bones and soft tissues of the chest wall can occasionaly be found.
(Fig.
13.,
14.)