Comparison of axial high-resolution CT and thin-section multiplanar reformation (MPR) for diagnosis of diseases of the pulmonary parenchyma: preliminary study in 49 patients.

Abstract

We evaluated the diagnostic utility of coronal multiplanar reformation (MPR) images produced by multi-detector row CT in diffuse and focal pulmonary parenchymal disease. A phantom study was conducted comparing spatial and low-contrast resolutions of axial high-resolution CT (HRCT) and coronal MPR. Non-spiral axial HRCT was performed with 2-mm collimation, and spiral CT was performed with 1-mm collimation and 8:1 pitch, from which MPR images were produced at 1.9-mm thickness and 5-mm intervals. Forty-nine patients were included in the clinical study. Three reviewers independently assessed the lesion conspicuity and disease extent on both axial HRCT and coronal MPR images, and the diagnostic utility of the coronal images was evaluated. Two reviewers subsequently assessed axial and coronal images separately, and the extent of abnormalities shown by each was compared. In phantom study, coronal MPR images were inferior to axial images but were considered adequate for clinical use. In clinical study, the image quality of MPR was regarded as good for observation of the lung parenchyma in all cases. The mean percentage of abnormalities for which 3 reviewers determined coronal MPR images as superior or additional information available was 22.1%, whereas 72.4% was regarded as comparable and 5.5% as inferior to axial images. Interobserver agreement was good (weighted kappa statistics 0.45-0.61). The extent of abnormality was judged to be shown equally on the axial and MPR images with good interobserver agreement (kappa statistics 0.63). Coronal MPR images may have an additional role to axial HRCT images in the clinical interpretation of lung parenchymal abnormalities.