Introduction:
The role of ultrasonography in detection of pleural effu-sion was first discovered in the 1960s (1). One decade later the diagnostic value of A-mode ultrasonography in identification of pleural effusion was reported to be 95% (2). Thus, the impression that ultrasonography is not a suitable modality for detection of chest lesions was re-jected at that time. Afterwards, various surveys were conducted evaluating the diagnostic accuracy of ultraso-nography and radiography in identification of pleural ef-fusion and most of them found a higher diagnostic value