Radial endobronchial ultrasound images for ground-glass opacity pulmonary lesions.

Radial endobronchial ultrasound (R-EBUS) is a useful tool for precise localisation of peripheral pulmonary lesions, but there have been no detailed reports about the use of R-EBUS images for ground-glass opacity (GGO). The R-EBUS images of 116 patients with GGO, who were diagnosed as having adenocarcinoma by R-EBUS with a guide sheath (EBUS-GS), were compared with the respective chest computed tomography findings. In 103 patients, R-EBUS images were correlated with the histological surgical specimens. R-EBUS images of GGO were identified based on the internal structure of the lesion and classified into two groups. Blizzard showed an enlarged, diffuse hyperintense acoustic shadow. Mixed blizzard showed a combination of blizzard and some diffuse heterogeneity with several hyperechoic dots and vessels. All pure GGO lesions (nine out of nine) were blizzard on R-EBUS. For part-solid GGOs, the percentage of mixed blizzard was inversely related to the amount of the GGO component. Histological findings from surgery revealed that all blizzard lesions were on the spectrum of adenocarcinoma in situ to well differentiated adenocarcinoma while majority (33 out of 64) of mixed blizzard lesions were moderately to poorly differentiated adenocarcinoma. R-EBUS types are important to locate GGOs prior to transbronchial sampling with EBUS-GS.