Relationship between Pleural Adenosine Deaminase Level and Patterns of Pleural Enhancement in Patients with a Tuberculous Pleural Effusion on CT Scan / 결핵및호흡기질환

ABSTRACT

Background: This study examined the relationship between the pleural adenosine deaminase (ADA) level and the patterns of pleural enhancement in patients with a tuberculous pleural effusion (TPE) shown on a CT scan. Methods: The charts and CT findings of 44 patients with TPE from February 2002 to October 2006 were reviesed retrospectively. A diagnosis of TPE was made by the pleural ADA level with a follow-up (24/44), sputum smear or culture of sputum (16/44), pleural fluid culture (3/44) or pleural biopsy (1/44). The patients were divided into two groups according to the ADA level(Group I [n=12] 40-70, Group II [n=32] >70 U/L). The presence or absence, maximal thickness and patterns of pleural enhancement were analyzed. The pattern of pleural enhancement was classified into diffuse or focal, smooth or irregular and interrupted or continuous. The difference in CT findings between groups I and group II were analyzed using an unpaired T test, Chi-square test and Z test. Results: All 44 patients showed diffuse pleural enhancement on the CT scans. The maximal pleural thickness of groups I and II was 1.83 +/- 1.03 mm (1-4 mm) and 3.63 +/- 1.78 mm (1-8 mm), respectively (p =0.0002). Pleural thickening > or = 5 mm was only demonstrated in 31.3% of patients in group II (10/32). Diffuse interrupted pleural thickening was noted in 91.7% (11/12) of patients in group I and 62.5% (20/32) in group II, respectively. Diffuse continuous pleural thickening was observed in 8.3% (1/12) of patients in group I and 37.5% (12/32) in group II, respectively (p=0.0748). Conclusion: Pleural thickening > or = 5 mm on the contrast enhanced CT is rare in patients with lymphocyte-dominant TPE in whom the pleural ADA level is between 40-70 U/L.