Whole slide imaging diagnostic concordance with light microscopy for breast needle biopsies

This study investigated the diagnostic accuracy of whole slide imaging (WSI) in breast needle biopsy diagnosis in comparison with standard light microscopy (LM). The study examined the effects of image capture magnification and computer monitor quality on diagnostic concordance of WSI and LM. Four pathologists rendered diagnoses using WSI to examine 85 breast biopsies (92 parts; 786 slides) consisting of benign and malignant cases. Each WSI case was evaluated using images captured at either ×20 or ×40 magnifications and viewed using a Digital Imaging and Communication in Medicine (DICOM) grade, color-calibrated monitor or a standard, desktop liquid-crystal display (LCD) monitor. For each combination, the WSI result was compared with the original, LM diagnosis. The overall concordance rate observed between WSI and LM was 97.1% (95% confidence intervals [CI]: 94.3%-98.5%). After a washout period, all cases were reviewed a second time by each pathologist after using LM, and the second LM diagnosis was compared with the WSI diagnosis rendered by the same pathologist. Intraobserver concordance between WSI and LM was 95.4% (95% CI: 92.2%-97.4%). The second LM diagnoses were also compared with the original LM diagnoses, and the observed interobserver LM concordance rate was 97.3% (95% CI: 93.1%-99.0%). The study data demonstrated that breast needle biopsy diagnoses rendered by WSI were equivalent to diagnoses rendered by LM. No diagnostic differences were detected between the underlying viewing system parameters of monitor quality and image capture resolution. The results of this study demonstrated that WSI can be effectively used in subspecialty diagnostic cases where a minimum amount of tissue is available.