Technegas ventilation SPECT for evaluating silicosis in comparison with computed tomography

Area of Science:

• Pulmonary Medicine
• Radiology
• Occupational Health

Background:

• Silicosis is a progressive lung disease characterized by interstitial fibrosis.
• Early detection of subtle morphologic changes and functional impairment is crucial for managing silicosis.
• Conventional and high-resolution CT have limitations in assessing early, subclinical ventilation heterogeneity.

Purpose of the Study:

• To compare subtle pulmonary parenchymal morphologic changes with ventilation function in silicosis patients.
• To evaluate the utility of technegas ventilation SPECT in assessing pulmonary ventilation heterogeneity in silicosis.
• To establish the correlation between ventilation parameters and the extent of silicotic lung changes.

Main Methods:

• Conventional CT, high-resolution CT, and technegas ventilation SPECT were performed on 25 silicosis patients and 6 controls.
• Pulmonary ventilation state was assessed using the coefficient of variation (CV) of technegas distribution.
• Multifactorial analysis was employed to correlate CV values with imaging findings and disease severity.

Main Results:

• Silicosis patients exhibited significantly higher CV values compared to controls, indicating increased ventilation heterogeneity.
• The CV value independently reflected the extent of interstitial findings, including nodules, septal thickening, and bullae.
• A strong correlation was observed between the CV value derived from technegas SPECT and the overall severity of silicosis.

Conclusions:

• The coefficient of variation (CV) derived from technegas ventilation SPECT is a sensitive index for detecting subclinical ventilation abnormalities in silicosis.
• CV serves as a valuable tool for quantifying the functional impact of silicosis and correlates with structural lung changes.
• Technegas ventilation SPECT offers a promising method for assessing the functional state of the silicotic lung and disease progression.