Three-dimensional and magnified CT images of displaying the imaging features of invasive adenocarcinoma of lung.

Objective: To discuss CT imaging characteristics of invasive adenocarcinoma of lung(IACL).

Methods: CT revealed the nodule of lung which pathology confirmed as IACL of 290 cases. Imaging data were retrospectively analyzed by dividing into high-risk group of 115 cases and low-risk group of 175. Three dimensional (3D) and magnified technology were used to show the nodules, which were observed and measured. Data of density, size and location of nodule were collected, and T-test or Chi-square test were performed.

Results: In 290 cases with IACL, all lesions appeared as nodule with lobulated and vascular/cord shadows, which can be clearly shown by the 3D and magnified images. 153 (52.8%) were solid nodule, 43 (14.8%) sub-solid, 29 (10.0%) ground glass and 65 (22.4%) nodule with cavity or vacuole. Nodules less than 1 cm were in 19 cases (6.5%), 1-2 cm in 180 (62.1%) and 2-3 cm in 91(31.4%).Nodules with spherical growth were in 109 cases (37.6%), non spherical growth in 181 (62.4%). Nodules with equal or less than four vascular/cord shadows were in 61 cases (21.1%) and more than four in 229 (78.9%). There are significant differences between high-risk and low-risk groups in density, size, and vascular/cord shadows (P < 0.05), no significant difference in nodule location and growth direction (P > 0.05).The growth angle were shown to be 45 ° or 135 ° in 144 (79.6%)cases, there was significant difference in the growth angle of sagittal plane between on the right and left (P = 0.032).

Conclusion: Magnified and 3D technology can clearly show the features of IACL, which are lobulated nodule with vascular/cord shadows, and the most are solid nodule. Nodule with cavity or vacuole and less than 2 cm more appear in low-risk group. Growth angle may reflect the growth pattern of IAC and the pathological characteristics.