Computed tomography of free pleural effusions.

Forty-three CT examinations of the thorax of patients referred for pleural effusion were reviewed. Both normal and thin irregularly thickened pleurae were associated with either neoplastic or non neoplastic disease. In these cases surgery, fine needle biopsy or pleuroscopy may be recommended, their performance being facilitated by the knowledge of the CT findings. Focal pleural masses or thick irregular pleura were consistently associated with malignancies; however, it was not possible to differentiate between primary and secondary forms. The simultaneous imaging of pleura, lungs and mediastinum by CT is very useful for the diagnosis, prognosis, staging and therapeutic approach of neoplasms.