[Correlation of early phase contrast enhancement of multi-detector row computed tomography to tumor stroma of nodular solid lung adenocarcinoma].

Background & Objective: Dynamic enhanced multi-detector row CT (MDCT) has been used in differential diagnosis of pulmonary nodules, but its mechanism was unclear yet. This study was to evaluate the correlations of early phase enhancement of MDCT to proportion and distribution of stroma in solid lung adenocarcinoma.

Methods: A total of 31 patients with lung adenocarcinoma underwent routine contrast-enhanced MDCT. All lesions were solid solitary pulmonary nodules confirmed by pathology. CT observation items included net enhancement and distribution of enhancement. Tumor morphology was observed with HE staining. About 25 fields of view of each specimen at low magnification were scanned to obtain digital data. Semi-auto segmentation software was used to calculate mean stroma proportion.

Results: The proportion of invasive stroma in tumors was correlated positively to CT enhancement value (r=0.483, P=0.006). Of the 31 nodules, 18 (58.1%) showed homogenous enhancement, 10 (32.3%) showed peripheral inhomogenous enhancement, 1 (3.2%) showed central inhomogenous enhancement, 1 (3.2%) showed asymmetrical inhomogenous enhancement, 1 (3.2%) showed no enhancement; 18 (58.1%) nodules showed mixed distribution of stroma, 11 (35.5%) showed peripheral distribution, 1 (3.2%) showed central distribution, 1 (3.2%) showed asymmetrical distribution. Most acinar adenocarcinomas had net enhancement of > 20 Hu, which was significantly higher than that of solid adenocarcinomas with mucin subtype (P=0.005).

Conclusions: Extent and pattern of CT enhancement of solid lung adenocarcinoma nodules reflect the proliferation and distribution of stroma, respectively. It is helpful to comprehend some false negative on CT enhancement by adequately understanding of the pathologic features of different subtypes of lung adenocarcinoma.