Role of transthoracic ultrasonography in evaluation of pleural thickening observed during medical thoracoscopy

Background and objective Ultrasound can evaluate pleural thickening; however, medical thoracoscopy permits direct inspection of the pleura, and biopsies are taken under direct vision. This study evaluated the degree of pleural thickening observed during medical thoracoscopy and compared it with the pleural thickness grades assessed and measured using transthoracic ultrasonography (TUS). Patients and methods A total of 118 cases with undiagnosed exudative pleural effusion were included. They were subjected to history taking, clinical examination, routine laboratory investigations, computed tomography chest, TUS to assess degree of parietal pleural thickening, and medical thoracoscopy to evaluate the observed degree of pleural thickening. Results There was a significant positive correlation between pleural thickening measured by US with thoracoscopic grades of thickness and significant positive correlation between pleural thickening grades measured by US and thoracoscopic grades of pleural thickness. Performance of thoracoscopy using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for assessment of pleural thickening in comparison with US as a standard tool for measurement was 36, 77, 52, 77, and 66%, respectively, whereas in assessing the shape of visceral pleura, this performance increased up to 89, 89, 85, 85, and 88%, respectively. Conclusion This study showed the superiority of TUS in assessment of parietal pleura thickening and chest wall invasion. In addition, TUS has other advantages as being noninvasive, less expensive, and no exposure to radiation. However, medical thoracoscopy can detect the visceral pleural shape better owing to the advantage of direct visualization of the lung surface.