Ces radiol. 2007, 61(4):392-399

Contribution of contrast-enhanced CT for detection of malignant etiology of pleural effusionOriginal article

Josef Novotný¹, Pavel Eliáš¹, Zdeněk Špriňar¹, Petr Habal², Vratislav Sedlák³

¹ Radiodiagnostická klinika LF UK a FN, Hradec Králové

² Kardiochirurgická klinika LF UK a FN, Hradec Králové

³ Plicní klinika LF UK a FN, Hradec Králové

Aim: The authors retrospectively analyze cohort of 137 patients presenting with pleural effusion of unknown etiology to assess the applicability of contrast-enhanced CT imaging for detection of malignant etiology.

Method: Over a period of 5 years we examined patients with pleural effusion of unknown etiology according to predesigned scanning protocol. All CT investigations were carried out on either of our two CT scanners (Somatom HiQ and Somatom Plus 4; Siemens, Erlangen, Germany). The first mentioned scanner was incremental, the second one was single helical. The examination started as a full length thorax CT without contrast injection followed by i.v. bolus enhancement according to predesigned protocol. There were 137 patients included in this study in whom the final diagnosis was confirmed, comprising 82 (60 %) males and 55 (40 %) females.

Results: In 82 patients (60 %) the final diagnosis of etiology of pleural effusion was malignant. The average age in malignant disease was 60.3 years and most often the malignancy occurred in the group of 61-70 years of age. More than half of malignant diagnoses was in men (57 %). Our focus was on detection of pleural changes indicating malignant etiology. Irregular thickening occurred in 58 patients. This represents 70.7 % of the malignant group. In 13 cases (15.9 %) there was no detectable opacification and in the remaining 11 cases (13.4 %) we detected regular pleural opacification. Malignant effusion was always exudative, in one case of lymphoma the character of effusion was chylothorax. Its density was not specific. The overall sensitivity of irregular (or nodular) pleural changes for detection of malignant pleural effusion reached in our study group 70.7 %, specificity was 96.4 %, positive predictive value was 96.7 % and negative predictive value was 68.8 %.

Conclusion: In cases of pleural effusion of unknown etiology the contrast-enhanced CT is a method which has the capacity to help significantly in discrimination of differential diagnoses. We assume that we were able to demonstrate the usefulness of contrast-enhanced CT in diagnostic algorithm when dealing with pleural effusion of unknown etiology. Our data show promising results of CT in this diagnostic effort however, we should always consider contrast-enhanced CT as one of complementing methods which has its limits.

Keywords: malignancy, pleural effusion, computed tomography

Accepted: August 15, 2007; Published: December 1, 2007  Show citation