Observer Variability for Classification of Pulmonary Nodules on Low-Dose CT Images and Its Effect on Nodule Management

Abstract

).q RSNA, 2015 Purpose:To examine the factors that affect inter-and intraobserver agreement for pulmonary nodule type classification on low-radiation-dose computed tomographic (CT) images, and their potential effect on patient management. Materials and Methods:Nodules (n = 160) were randomly selected from the Dutch-Belgian Lung Cancer Screening Trial cohort, with equal numbers of nodule types and similar sizes. Nodules were scored by eight radiologists by using morphologic categories proposed by the Fleischner Society guidelines for management of pulmonary nodules as solid, part solid with a solid component smaller than 5 mm, part solid with a solid component 5 mm or larger, or pure ground glass. Inter-and intraobserver agreement was analyzed by using Cohen k statistics. Multivariate analysis of variance was performed to assess the effect of nodule characteristics and image quality on observer disagreement. Effect on nodule management was estimated by differentiating CT follow-up for ground-glass nodules, solid nodules 8 mm or smaller, and part-solid nodules smaller than 5 mm from immediate diagnostic work-up for solid nodules larger than 8 mm and part-solid nodules 5 mm or greater. Results: Conclusion:There is moderate inter-and intraobserver agreement for nodule classification by using current recommendations for low-radiation-dose CT examinations of the chest. Discrepancies in nodule categorization were mainly caused by disagreement on the size and presence of a solid component, which may lead to different management in the majority of cases with such discrepancies.q RSNA, 2015

Ultralow-dose CT with tin filtration for detection of solid and sub solid pulmonary nodules: a phantom study

“…20 These above-mentioned problems were not noted in our study, even in images reconstructed with high ADMIRE strength levels (3 and 5). The discordance in classifying pulmonary nodules was already described by van Riel et al 22 in a recent work who stated that there is a substantial interobserver variability for nodule classification on low-radiation dose scans.…”

Lung nodules: size still matters

“…In this context, uncertainties exist not only in the nodule measurement, due to difficulties in delineating nodule margins and different densitometric components of PSNs, but also in the classification of nodule morphological characteristics (i.e. pGGN or PSN) [45,46].…”

“…Two recent studies focused on the evaluation of observer variability in visual classification of SSNs and the potential implication on patient management, both in a screening and nonscreening setting [45,47]. Agreement values were moderate (intra-and inter-observer agreement κ-values of 0.57 and 0.51, respectively in the screening setting; inter-observer agreement κ-value of 0.56 in the nonscreening setting) and discordance in nodule classification was mainly due to the assessment of the solid component, in terms of presence and size [45,47].…”

Adenocarcinoma in pure ground glass nodules: histological evidence of invasion and open debate on optimal management

“…(16). However, there are known limitations from the inter-and intra-observer variability in such qualitative features of pulmonary nodules (17). The attempt to reduce subjective variability in the definition of such qualitative features is being endorsed by software developers because subtle morphological differences in pGGN can play a significant role in prognostication, and it is particularly relevant when assessing the nodule on a single (18) and other types of nodule (19).…”