Chest ImagingPneumoconiosis
a term used to describe the non-neoplastic reactions of the lungs to inhaled dust particles. Although some authors include organic as well as mineral dust, many limit the term to inorganic dust, notably coal, silica and asbestos (Table 1).
Pneumoconiosis, Table 1. List of pneumoconioses.
ILO Classification
This is a classification system that assists in the reproducible interpretation of the chest radiograph abnormalities in subjects with pneumoconiosis (Table 2). It is accompanied by a set of standard radiographs. Pulmonary opacities and reactive pleural, pericardial and hilar changes are described and coded. Pulmonary opacities are divided into two major groups: small round opacities up to 1 cm in diameter and opacities larger than 1 cm in diameter.
The small opacities In this group the opacities are classified according to shape and diameter of the predominant opacities. p, q and r are round opacities with diameters of up to 1.5, between 1.5 and 3 and between 3 and 10 mm, respectively. When the opacities are irregular, they cannot be meaningfully measured so they are categorized as s when they are fine, irregular or linear, as t when moderately coarse and as u when coarse.
Profusion is also scored in 4 categories (03):
Each category is indicated by two numbers. The first number is the category finally chosen, the second is the alternative category considered.
The large opacities are classified in three categories according to their size and extent.
The margins of the large opacities are characterized as well defined (wd) or ill defined (id).
Thickness of pleural opacities is graded a, b or c when maximum thickness is 5 mm, between 5 and 10 mm or greater than 10 mm, respectively. Extent of pleural involvement is coded as grade 0 when pleural thickening is not present or less than grade 1, as grade 1 when the total length of uni- or multifocal pleural thickening does not exceed a quarter of the length of the lateral chest wall, and as grade 2 when the total length does not exceed half the length of the lateral chest wall.
Delineation of the diaphragm and of the cardiac borders is also graded.
Finally location and extent of pleural calcifications is scored.
Pneumoconiosis, ILO classification, Table 1.
|
|---|
| SMALL ROUNDED OPACITIES |
| The opacities are classified according to the diameter of the predominant opacities: |
| p: round opacities up to 1.5 mm in diameter | (blotchy) irregular opacities
| The profusion category is based on the concentration of opacities in the various lung zones. The standard radiographs illustrate the intermediate range for each category |
| Category 0: small opacities absent or less profuse than in category 1 |
| Category 1: small opacities definitely seen but few in number |
| Category 2: numerous small opacities with normal lung vasculature partly obscured |
| Category 3: very numerous opacities where the lung vasculature is totally obscured |
| RU, RM, RL, LU, LM, LL: indicate the lung zones in which the opacities occur. As with round opacities, each side is divided into upper, middle and lower zones. |
| LARGE OPACITIES |
| Category A: one or more opacities whose combined diameters do not exceed 5 cm |
| Category B: one or more opacities, larger and more numerous than A, whose combined area does not exceed the equivalent of the right upper zone |
| Category C: one or more opacities whose combined area is larger than the equivalent of the right upper zone |
| The extension wd (well-defined) or id (ill-defined) is added to the size code to characterize the margins of the opacities.
PG |
PG - JV