MRI and CT in the differential diagnosis of pleural disease.

Study objective To explore the role of MRI in thedifferential diagnosis of pleural disease. Patients Forty-two patients with pleural disease were included. Method Retrospective study. All patients were examinedwith both CT and MRI. The morphologic features of pleural lesions and magnetic resonance signal intensity on T1-weighted, T2-weighted, and contrast-enhanced T1-weighted images were evaluated. Results Mediastinal pleural involvement, circumferentialpleural thickening, nodularity, irregularity of pleural contour, and infiltration of the chest wall and /or diaphragm were most suggestive ofa malignant cause both on CT and MRI. Pleural calcification on CT wassuggestive of a benign cause. Contrary to what has been previouslyreported in the literature, neither on CT nor on MRI, pleural thickness>1 cm revealed significant difference between malignant and benignpleural disease (p > 0.05, χ 2 test). High signalintensity in relation to intercostal muscles on T2-weighted and /orcontrast-enhanced T1-weighted images was significantly suggestive for amalignant disease. Using morphologic features in combination with thesignal intensity features, MRI had a sensitivity of 100% and aspecificity of 93% in the detection of pleural malignancy. Conclusion When signal intensity and morphologic featuresare assessed, MRI is more useful and therefore superior to CT indifferentiation of malignant from benign pleuraldisease.