CT imaging of bronchus related to solitary pulmonary lesion: comparison of minimum intensity projection and multi-planar reconstruction / 中华放射学杂志

ABSTRACT

Objective To investigate the clinical value of 64-slice computed tomography with MinIP and MPR for imaging the bronchus related to a solitary pulmonary lesion (SPL). Methods Seventy-five subjects with solitary pulmonary lesions underwent chest 64-slice CT and their bronchi were analyzed retrospectively. All images of thin-section (0.625 mm) were reconstructed with MPR and MinIP into images of 1, 2, 3, and 5 mm thickness and 1 mm gap in two orthogonal planes along the long axis of bronchus related to the SPL. The image quality of four series of MinIP and MPR images was evaluated in the aspect of bronchus visibility and pulmonary vascular masking. One-way ANOVA with Bonferroni correction and interclass correlation coefficient were used in the statistical analysis. Results (1) The mean scores of display of the bronchi on MinIP images of four series (4.85, 4.77 and 4.84, 4.63 and 4.67, 4.25 and 4.28, in 1, 2, 3, and 5 mm thickness, respectively) and on MPR images of 1 or 2 mm thickness (4.77 and 4.76, 4.04 and 4.27, in 1 and 2 mm thickness, respectively) were good or excellent. MPR images of 1 mm thickness and MinIP images of 1-3 mm thickness showed no significant differences (t=0.318, P> 0.05 for all), but they were superior to MinIP images of 5 mm thickness (t=6.318 and 6.610, P＜0.01). MPR images of 2 mm thickness were inferior to MinIP images of 1-3 mm thickness (t=5.003-8.958, P＜0.01), but there was no significant difference between MPR images of 2 mm thickness and MinIP images of 5 mm thickness (t=1.794 and 0.3181, all P> 0.05). (2) The effect of suppression of pulmonary vascular markings on MinIP images was better with the increase of slice thickness (F=45.312 and 40.415, P＜0.01). The mean scores of MinIP images of 3 mm and 5 mm thickness (4.67 and 4.64, 5.00 and 4.97, for 3 and 5 mm thickness, respectively) were good or excellent, but MinIP images of 2 mm thickness were just acceptable. Conclusion MinIP images of 3 mm thickness may display the bronchus related to SPL more clearly.