The use of ultrasound in detecting and defining ground-glass opacities: results of an ex vivo evaluation

To evaluate the role of ultrasound in detecting and defining ground-glass opacities (GGOs) in surgical specimens of patients undergoing thoracoscopic diagnostic resection.

OBJECTIVES: To evaluate the role of ultrasound in detecting and defining ground-glass opacities (GGOs) in surgical specimens of patients undergoing thoracoscopic diagnostic resection.METHODS: We performed an observational single-centre study of all consecutive patients undergoing thoracoscopic diagnostic resection of GGOs. In each patient, the specimen was scanned with ultrasound; then, a needle was inserted into the lesion to facilitate its detection by the pathologist. We evaluated the rate of detection with ultrasound, compared the size and depth measurements of the lesions as determined from ultrasound scans with those from the histological specimens and correlated the ultrasound findings with the histological subtypes of adenocarcinomas.RESULTS: We reviewed 17 tissue samples. The final diagnoses were 1 (6%) atypical adenomatous hyperplasia, 5 (29%) adenocarcinomas in situ, 4 (24%) minimally invasive adenocarcinomas and 7 (41%) invasive adenocarcinomas. All tumours were successfully identified using ultrasound. The size (P = 0.87) and depth (P = 0.25) of the lesions measured with ultrasound did not significantly differ from the measurements obtained from the histological specimens. In addition, ultrasound size (r = 0.945; P < 0.0001) and depth (r = 0.588; P = 0.013) were significantly correlated with the pathologicalmeasurements. All lesions with hyperechoic findings (n = 6) were pure GGOs, whereas lesions withmixed echoic (n= 11) patterns were mixed GGOs. We were unable to differentiate the histological subtypes of adenocarcinomas using the ultrasound scans.CONCLUSIONS: Detection of GGOs on ultrasound scans is feasible, but differentiation of the histological subtypes of adenocarcinomas is not possible. The next step is to evaluate the intraoperative reproducibility of our results.