<qa>  What is the name of the type of labeling that is used to increase the diagnostic yield?To increase the diagnostic yield, patients who are referred for lung biopsy, will undergo the technique of preoperative labeling: small indeterminate lung nodules are frequently invisible and impalpable. There is an encouraging literature which indicates that preoperative labeling of lung lesions with a small 0.30.5ml volume of methylene blue which acts a guidance track for the surgeon, may significantly improve the diagnostic yield from surgical open or videoassisted thoracoscopic biopsy. 