title: Postediting prostate magnetic resonance imaging segmentation consistency and operator time using manual and computer-assisted segmentation: multiobserver study.
abstract: Prostate segmentation on T2w MRI is important for several diagnostic and therapeutic procedures for prostate cancer. Manual segmentation is time-consuming, labor-intensive, and subject to high interobserver variability. This study investigated the suitability of computer-assisted segmentation algorithms for clinical translation, based on measurements of interoperator variability and measurements of the editing time required to yield clinically acceptable segmentations. A multioperator pilot study was performed under three pre- and postediting conditions: manual, semiautomatic, and automatic segmentation. We recorded the required editing time for each segmentation and measured the editing magnitude based on five different spatial metrics. We recorded average editing times of 213, 328, and 393 s for manual, semiautomatic, and automatic segmentation respectively, while an average fully manual segmentation time of 564 s was recorded. The reduced measured postediting interoperator variability of semiautomatic and automatic segmentations compared to the manual approach indicates the potential of computer-assisted segmentation for generating a clinically acceptable segmentation faster with higher consistency. The lack of strong correlation between editing time and the values of typically used error metrics ([Formula: see text]) implies that the necessary postsegmentation editing time needs to be measured directly in order to evaluate an algorithm's suitability for clinical translation.
authors.affiliation: London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Robarts Research Institute, 1151 Richmond Street, London, Ontario N6A 5B7, Canada; University of Western Ontario, Graduate Program in Biomedical Engineering, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Maysam
authors.initials: M
authors.lastname: Shahedi
authors.affiliation: University of Western Ontario, Robarts Research Institute, 1151 Richmond Street, London, Ontario N6A 5B7, Canada; University of Western Ontario, Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Derek W
authors.initials: DW
authors.lastname: Cool
authors.affiliation: University of Western Ontario , Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Cesare
authors.initials: C
authors.lastname: Romagnoli
authors.affiliation: London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Medical Biophysics, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Bauman
authors.affiliation: University of Western Ontario , Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Bastian-Jordan
authors.affiliation: London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: George
authors.initials: G
authors.lastname: Rodrigues
authors.affiliation: London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Belal
authors.initials: B
authors.lastname: Ahmad
authors.affiliation: London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Lock
authors.affiliation: University of Western Ontario, Robarts Research Institute, 1151 Richmond Street, London, Ontario N6A 5B7, Canada; University of Western Ontario, Graduate Program in Biomedical Engineering, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Medical Biophysics, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Fenster
authors.affiliation: London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Graduate Program in Biomedical Engineering, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Medical Biophysics, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Ward
keywords: editing time; image segmentation; magnetic resonance imaging; observer study; prostate; repeatability