Asbestos Lung

Case History:  61 year old male who worked in an asbestos factory from 1949 to 1991.   He was foud to have an abnormality on plain CXR in 1991.  Detailed examinations made the diagnosis of asbestos lung.   Since June 1991 he has complained of exertional dyspnea.   Brinkman index 420.   Pulmonary function tests show VC=52%; FEV1=89.5%.

Radiological Examinations:

^99mTc MAA perfusion planar scintigraphy

Technegas planar scintigraphy

¹³³Xe inhalation study

Comments:  Plain chest x-rays reveal linear and reticular densities in both lung bases inducing a marked reduction of lung volume.   HRCT shows ring shadows and increased lucency in the bi-lateral lung bases accompanied by pleural thickening and bronchiectatic changes. 

Perfusion lung scintigraphy suggests lung volume reduction but no particular perfusion defects are recognised. 

The single breath ¹³³Xenon gas inhalation study is of poor quality due to inadequate inhalation of the gas, but still indicates a volume reduction of the lung bases without significant ventilation defect.  The equilibrium image shows a similar distribution to the perfusion counterpart.   Wash-out images indicate some delay in the left lung base suggesting the presence of chronic obstructive lung disease. 

Multiple projections of Technegas planar images revealed similar lung volume reduction of the right and left bases as noted on the ¹³³Xenon study, but did not show evidence of either inhomogeneous distribution or ventilation defects.

Technegas transverse SPECT series

General Comments:   SPECT imaging showed decreased deposition of inhaled Technegas more markedly in the posterior aspects of the both lungs than in the anterior aspect, indicating that ventilation was more disturbed in the posterior than the anterior aspect.   The sites of deposition of inhaled Technegas nearly corresponded to the lung regions where CT had revealed pathologic findings.   Thus regional lung function can be assessed effectively by Technegas studies.