The effect of late-phase contrast enhancement on semi-automatic software measurements of CT attenuation and volume of part-solid nodules in lung adenocarcinomas

Eur J Radiol. 2016 Jun;85(6):1174-80. doi: 10.1016/j.ejrad.2016.03.027. Epub 2016 Mar 30.


Objectives: To evaluate the differences in semi-automatic measurements of CT attenuation and volume of part-solid nodules (PSNs) between unenhanced and enhanced CT scans.

Materials and methods: CT scans including unenhanced and enhanced phases (slice thickness 0.625 and 1.25mm, respectively) for 53 adenocarcinomas presenting as PSNs in 50 patients were retrospectively evaluated. For each nodule, semi-automatic segmentation provided the diameter, mean attenuation, mass, and volume of a whole nodule and its solid component. Interscan variability and statistical significance of the differences in those measures according to the adenocarcinoma category were evaluated by one reader.

Results: All parameters except for the mean attenuation of the solid components, were significantly increased on enhanced CT (p<0.05). For the whole nodule, the mean relative differences were as follows: the longest diameter, 1.4% (limits of agreement, -6.2-9.1); volume, 2.4% (-26.7-31.4); mass, 7.0% (-11.3-25.2); mean attenuation, 2.7% (-5.6-11). For the nodule's solid component, those differences were as follow: the longest diameter, 6.9% (-34.4-48.2); volume, 17.9% (-77.8-113.7); mass, 18.8% (-77.8-115.4). The differences of measures between the unenhanced and enhanced CT were not significantly different between two groups of adenocarcinoma in situ/minimally invasive adenocarcinomas and invasive adenocarcinomas (p>0.05).

Conclusions: As most volumetric and attenuation measurements changed significantly after contrast enhancement, care should be taken in comparing unenhanced and enhanced CT in the evaluation of PSNs.

Keywords: Adenocarcinoma; Contrast media; Lung cancer; Lung nodule; Solitary pulmonary nodule; Subsolid nodule.

MeSH terms

  • Adenocarcinoma / diagnostic imaging*
  • Adenocarcinoma of Lung
  • Adult
  • Aged
  • Contrast Media*
  • Female
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Lung / diagnostic imaging
  • Lung Neoplasms / diagnostic imaging*
  • Male
  • Middle Aged
  • Radiographic Image Enhancement / methods*
  • Retrospective Studies
  • Software
  • Solitary Pulmonary Nodule / diagnostic imaging*
  • Tomography, X-Ray Computed / methods*


  • Contrast Media