High resolution computed tomography of the chest is the gold standard imaging modality for most pulmonary diseases. However, the associated high expenses, radiation exposure , and its limited possibility for bedside use are a limitation. Transthoracic ultrasonograghy is used progressively for evaluation of pulmonary diseases. Its non invasive nature , relatively low price ,portability for bedside use, and high reproducibility of results allows for incorporation of imaging findings with clinical data. Although Transthoracic ultrasonograghy is not an alternative to High resolution computed tomography,it can potentially provide useful supplemental information in certain specific situations ,such as for rapid bedside diagnostic assessment of dyspneic patients. B-line is a common and significant abnormal sign used for diagnostic appraisal by Transthoracic ultrasonograghy, but it cannot define the exact underlying pathologic feature on a lung ultrasound. When the lung parenchymal pathology reaches the lung surface ,certain characteristic changes of the pleural line can be detected by means of the good imaging made possible by high-resolution Transthoracic ultrasonograghy ,but the application and strength of pleural line abnormalities in the differential diagnosis of lung diseases has not been adequately explored . Existing literature on the illustration of the pleural line is scarce ,and the shape of pleural line has not been adequately investigated and described ,especially in comparison with Computed tomography findings. Most studies that have investigated pleural lines are confined to the sub population with interstitial lung diseases.
High resolution computed tomography of the chest is the gold standard imaging modality for most pulmonary diseases. However, the associated high expenses, radiation exposure , and its limited possibility for bedside use are a limitation.