SARCOIDOSIS ACTIVITY - CORRELATION OF HRCT FINDINGS WITH THOSE OF GA-67 SCANNING, BRONCHOALVEOLAR LAVAGE, AND SERUM ANGIOTENSIN-CONVERTING ENZYME ASSAY

Purpose: The objective of this study was to correlate the findings of sarcoidosis on high resolution CT (HRCT) with indexes of disease activ ity as measured with Ga-67 scan, bronchoalveolar lavage (BAL), and ser um angiotensin-converting enzyme (SAGE) assay. Method: Twenty-nine pat ients with proven sarcoidosis underwent HRCT scan, Ga-67 scan, BAL, an d SAGE assay within a 1 month period. The extent of parenchymal involv ement by nodules, consolidation, ground-glass attenuation, and linear opacities was quantified to the nearest 10% of surface area affected o n the CT examination. Whole-lung gallium uptake was quantified and the percentage of BAL-recovered lymphocytes (BAL-%LC) and SAGE levels obt ained by chart review. CT scores of disease extent were correlated wit h measured indexes of activity using the Spearman rank correlation coe fficient. Results: The mean extent of nodules, consolidation, ground-g lass attenuation, and linear opacities on HRCT images was 15.1 +/- 16. 6, 1.6 +/- 4.0, 17.5 +/- 25.4, and 7.6 +/- 9.6%, respectively. The ext ent of nodules and consolidation correlated with the intensity of lung gallium uptake (r = 0.46, p < 0.02), BAL-%LC (r = 0.50, p < 0.01), an d SAGE levels (r = 0.38, p < 0.05). No significant correlation was fou nd between extent of ground-glass attenuation or linear opacities with any indexes of disease activity. Conclusion: On HRCT scan, nodules an d consolidation in sarcoidosis reflect disease activity as measured by Ga-67 scan, BAL, and SAGE assay.