Value of multiplanar reformations (MPR) in multislice spiral CT.

Purpose: To evaluate the quality of multiplanar reformations (MPR) of multidetector spiral-CT (MD-CT) data sets of the chest based on anatomic criteria. Methods: 90 patients with suspected or known diseases of the lung parenchyma underwent thoracic MD-CT with l-mm collimation. Axial scans were reconstructed with l-mm slice width and 0.6-mm reconstruction increment. Coronal and sagittal MPRs were reconstructed with 3, 5 and 8 mm thickness from the axial scans. Three blinded readers rated image quality based on several anatomic criteria and the presence of different artifacts using a 5-point scale. The scores for MPRs were compared with those of 5-mm thick axial scans. Results: All anatomical structure were equally well depicted on MPRs as on axial scans with very good interobserver correlation (kappa 0.69-0.76). Only the lung parenchyma directly adjacent to the heart and the great vessels were visualized with limited quality due to cardiac pulsation artifacts. Advantages of sagittal MPRs include the sharper delineation of interlobar fissures and thus improved anatomic localization of a lesion. Coronal reformations also offer improved anatomic orientation in comparison with 5-mm axial scans. A slice thickness of 5 mm for MPRs yielded best results. Conclusions: MPRs allow an unrestricted assessment of the lung. Sagittal and coronal reformations improve the topographical visualization of chest anatomy.