Early and delayed phases of contrast-enhanced CT for evaluating patients with malignant pleural effusion. Results of pairwise comparison by multiple observers

Objective:To compare images from early and delayed phases of contrast-enhanced thoracic CT for assessing pleural thickening or nodules in a series of patients with malignant pleural effusions.Methods:Blinded images from 36 patients with malignant pleural effusions showing pleural lesions in both early (35 s delayed) and delayed (70 s delayed) phases of thoracic and abdominal contrast-enhanced CT scan were retrospectively assessed by six observers. First, images were individually scored in a six-point scale grading the quality of visualization of pleural findings such as pleural thickening or nodules. This was followed by a paired analysis, where the readers had to choose the one showing the highest quality between two images presented together corresponding to both phases of the same patient showing the same pleural lesion. When possible, contrast attenuation of the abnormal pleura was measured. Statistical analysis was performed by using paired t-test and χ 2.Results:Mean attenuation of pleural lesions w...