title: Core samples for radiomics features that are insensitive to tumor segmentation: method and pilot study using CT images of hepatocellular carcinoma.
abstract: The purpose of this study is to investigate the utility of obtaining "core samples" of regions in CT volume scans for extraction of radiomic features. We asked four readers to outline tumors in three representative slices from each phase of multiphasic liver CT images taken from 29 patients (1128 segmentations) with hepatocellular carcinoma. Core samples were obtained by automatically tracing the maximal circle inscribed in the outlines. Image features describing the intensity, texture, shape, and margin were used to describe the segmented lesion. We calculated the intraclass correlation between the features extracted from the readers' segmentations and their core samples to characterize robustness to segmentation between readers, and between human-based segmentation and core sampling. We conclude that despite the high interreader variability in manually delineating the tumor (average overlap of 43% across all readers), certain features such as intensity and texture features are robust to segmentation. More importantly, this same subset of features can be obtained from the core samples, providing as much information as detailed segmentation while being simpler and faster to obtain.
authors.affiliation: Stanford University , Department of Electrical Engineering, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Echegaray
authors.affiliation: Stanford University , Department of Radiology, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: Olivier
authors.initials: O
authors.lastname: Gevaert
authors.affiliation: Stanford University , Department of Radiology, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Shah
authors.affiliation: Stanford University , Department of Radiology, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: Aya
authors.initials: A
authors.lastname: Kamaya
authors.affiliation: Stanford University , Department of Radiology, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: John
authors.initials: J
authors.lastname: Louie
authors.affiliation: Stanford University , Department of Radiology, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: Nishita
authors.initials: N
authors.lastname: Kothary
authors.affiliation: Stanford University , Department of Radiology, 650 Serra Mall, Stanford, California 94305, United States.
authors.forename: Sandy
authors.initials: S
authors.lastname: Napel
keywords: CT; hepatocellular carcinoma; image features; radiomics; segmentation; stability