Table 1.
Annotation of nodule characteristic scoring.
Fig 1.
Comparison of manual (left) and CIP-based (right) segmentation.
Yellow shaded region indicated the disagreement (or region of uncertainty) between contours performed by four radiologists (bottom left) or different CIP-based seed locations (bottom right). In this example, the region of uncertainty for manual segmentation was 3222 ml while the region was only 46 ml for the CIP-based segmentation. dsiCIP was ≈ 100%, while dsimanual was 88%.
Fig 2.
Robustness (or stability) of the manual and CIP-based segmentation.
The robustness of the manual and CIP-based segmentation assessed with the region of uncertainty (δ) and Dice similarity index (dsi).
Fig 3.
Bland-Altman plots highlights the differences between and
for all nodules. The 95% interval of the differences are depicted by the blue dotted lines. Solid red line is the average difference between
and
(= 318ml).
Fig 4.
Examples of nodules that were segmented by radiologists manually and CIP segmentations.
a) The robustness of the CIP segmentation was excellent, while substantial interobserver variability was observed in manual segmentation. CIP segmentation was also in excellent agreement with manual contours. However, CIP segmentation was observed to include part of the chest wall (indicated by an arrow) b) Despite being perfectly robust CIP segmentation, it included the region of the normal lung in proximity of the small nodule. c) Cavitation in the center of the nodule. Poor CIP segmentation performance was found. d) Non-solid (ground glass opacity) nodule with poorly defined boundary and subtle appearance is indicated by the red arrow. Poor CIP segmentation performance was found.
Fig 5.
The relationships between nodule characteristics, nodule volume, and DSIAgree.
This figure highlights the relationships between nodule characteristics, nodule volume, and DSIAgree. Calcification: Solid = solid calcification, Central = central calcification, None = no calcification. Lobulation: None = not lobulated. Spiculated: None = not spiculated. Texture: Mixed = Semi-solid nodules. Malignancy: Unlikely = unlikely for cancer, Suspicious = suspicious for cancer. Nodule Volume: Q1 = 162ml, Q1–Q3 = 162ml to 796ml, and Q3 = 796ml; Q = quantile.
Table 2.
Distribution of nodule characteristics.
Median , median DSIAgree and their corresponding interquartile ranges (IQR) for each nodule characteristic.
Table 3.
Brief descriptions of five algorithms for ground glass opacity (GGO) or partly solid nodule segmentation.