Study on intraoperative ultrasonographic features of small lung cancer lesions with ground glass nodules on computerized tomography

Abstract

Objective: This study intends to compare the preoperative high resolution computed tomography (HRCT) and intraoperative ultrasonic (partial contrast-enhanced ultrasonic) images of a group of small lung cancer lesions with ground glass nodules (GGN) on computerized tomography (CT), and to explore the imaging features of small lung cancer lesions with GGN and the sonographic findings of some GGN contrast-enhanced ultrasonic (CEUS).

Methods: 41 patients with CT with ground glass nodules confirmed by pathology in Cancer Hospital of China Medical University from January 2019 to December 2021 were collected. Among them, 15 patients were examined by intraoperative contrast-enhanced ultrasonic. All patients were examined by high resolution computed tomography (HRCT) before operation and intraoperative ultrasonic during video-assisted thoracoscopic surgery (VATS). SPSS 22.0 software was adopted for data processing. If the data were in accordance with normal distribution, t-test was adopted between groups, and Fisher exact probability test was adopted for univariate analysis. P < 0.05 suggested that the difference was statistically significant.

Results: (1) There was significant difference between pure ground glass nodule (pGGN) and partial ground glass nodule (mGGN) in nodule diameter, shape, marginal spiculation sign, lobulation sign, pleural traction or indentation sign. There was significant difference in the edge of nodules and the short diameter of lesions between pGGN and mGGN (P < 0.05). (2) There was significant difference in nodule size between preoperative HRCT and intraoperative ultrasonic (P < 0.05). There was a significant difference in the size of GGN between preoperative HRCT and intraoperative ultrasonic (P < 0.05). There was significant difference in the time to start enhancement (TE) and the time to peak (TTP) between GGN contrast-enhanced ultrasonic and collapsed lung tissue (P < 0.05). Among the 15 cases of CEUS, 13 cases of GGN showed “slow in and fast out” mode compared with collapsed lung tissue, and 2 cases of GGN showed “fast in and fast out” mode compared with collapsed lung tissue.

Conclusion: (1) In VATS operation of GGN lung cancer, the lesions observed by ultrasonic can be distinguished according to the shape and edge characteristics of the lesions on CT before operation. (2) In terms of intraoperative ultrasonographic features of VATS, mGGN has a longer short diameter of lesions than pGGN, and the edge of lesions is more lobulated. (3) Contrast-enhanced ultrasonic mostly showed low enhancement in GGN micro-lung cancer, and its contrast-enhanced mode was “slow in and fast out”. The use of this feature is beneficial to the confirmation of micro-lung cancer nodules during operation.