Purpose: To evaluate the ability to identify early adenocarcinomas (Noguchi types A/B) from peripheral lung adenocarcinomas of less than 20 mm in diameter based on CT profile curves.
Materials and methods: High resolution CT (HRCT) of 33 patients with peripheral lung adenocarcinoma less than 20 mm in diameter were reviewed retrospectively. CT attenuation values were measured using profile curves. Maximum and minimum CT values among profile curves of tumors were correlated with pathological diagnosis based on Noguchi type.
Results: As adenocarcinoma type worsened, CT values increased in both minimum and maximum values for the central portion of the tumor, although maximum values did not differ between type C and types D/E/F. Maximum CT values were significantly higher for type B than for type A (p = 0.0029). Minimum CT values were significantly lower for type B than for C (p = 0.0022). In both maximum and minimum CT values, significant differences existed between Noguchi types A/B and all other Noguchi types (p < 0.0001, p < 0.0001) and between types A/B and type C (p = 0.0013, p = 0.0003).
Conclusion: CT profile curves are relatively simple to derive and offer a consistent method of differentiating Noguchi types A/B from type C and from types C/D/E/F.