title: Use of a semi-automated cardiac segmentation tool improves reproducibility and speed of segmentation of contaminated right heart magnetic resonance angiography.
abstract: Three-dimensional printing has an increasing number of clinical applications in pediatric cardiology. Time required for dataset segmentation and conversion to stereolithography (STL) format remains a significant limitation. We investigated the impact of semi-automated cardiovascular-specific segmentation software on time and reproducibility of segmentation. Magnetic resonance angiograms (MRAs) of 19 patients undergoing intervention for right ventricular outflow lesions were segmented to demonstrate the right heart. STLs were created by two independent clinicians using semi-automated cardiovascular segmentation (SAS) and traditional manual segmentation (MS). Time was recorded and geometric STL disagreement was determined (0 % = no disagreement, 100 % = complete disagreement). MRA datasets were categorized as clean when only right heart structures were present in the MRA, or contaminated when left heart structures were also present and required removal. Eighteen (seven clean and 11 contaminated) cases were successfully segmented with both methods. Time to STL for clean datasets was faster with MS than SAS [median 209 s (IQR 192-252) vs. 296 s (272-317), p = 0.018] while contaminated datasets were faster with SAS [455 s (384-561) vs. 866 s (310-1429), p = 0.033]. Interobserver STL geometric disagreement was significantly lower using SAS than MS overall (0.70 ± 1.15 % vs. 1.31 ± 1.52 %, p = 0.030), and for the contaminated subset (0.81 ± 1.08 % vs. 1.75 ± 1.57 %, p = 0.036). Most geometric disagreement occurred at areas where left heart contamination was removed. Semi-automated segmentation was faster and more reproducible for contaminated datasets, while MS was faster but equally reproducible for clean datasets. Semi-automated segmentation methods are preferable for contaminated datasets and continued refinement of these tools should be supported.
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA. animesh.tandon@utsouthwestern.edu.|Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA. animesh.tandon@utsouthwestern.edu.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA. animesh.tandon@utsouthwestern.edu.
authors.forename: Animesh
authors.initials: A
authors.lastname: Tandon
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.|Medical Physics, Guy's and St. Thomas' NHS Foundation Trust, London, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Byrne
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
authors.forename: Maria de Las
authors.initials: Mde L
authors.lastname: Nieves Velasco Forte
authors.affiliation: Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA.
authors.forename: Adrian K
authors.initials: AK
authors.lastname: Dyer
authors.affiliation: Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA.
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Dillenbeck
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA.
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Greil
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA.
authors.forename: Tarique
authors.initials: T
authors.lastname: Hussain
mesh_terms: D000293:Adolescent; D001331:Automation; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006330:Heart Defects, Congenital / Q000150:complications; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015588:Observer Variation; D011237:Predictive Value of Tests; D066330:Printing, Three-Dimensional; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012984:Software; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: 3D printing; Cardiac segmentation; Magnetic resonance angiography; Stereolithography