TY - JOUR
T1 - Segmentation errors and intertest reliability in automated and manually traced hippocampal volumes
AU - Brinkmann, Benjamin H.
AU - Guragain, Hari
AU - Kenney-Jung, Daniel
AU - Mandrekar, Jay
AU - Watson, Robert E.
AU - Welker, Kirk M.
AU - Britton, Jeffrey W.
AU - Witte, Robert J.
N1 - Funding Information:
Funding Information This study was supported by research funding from the Mayo Radiology and Neurology Departments. H. Guragain was supported during this study by National Institutes of Health R01NS097719 and a gift from Mr. and Mrs. David Hawk. The authors thank P. Weishaar, L. Padgett, and B. Knoepke of the Mayo 3D lab for performing manual hippocampal tracing. This study was supported by research funding from the Mayo Radiology and Neurology Departments. H. Guragain was supported during this study by National Institutes of Health R01NS097719 and a gift from Mr. and Mrs. David Hawk.
Publisher Copyright:
© 2019 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association.
PY - 2019/9/1
Y1 - 2019/9/1
N2 - Objective: To rigorously compare automated atlas-based and manual tracing hippocampal segmentation for accuracy, repeatability, and clinical acceptability given a relevant range of imaging abnormalities in clinical epilepsy. Methods: Forty-nine patients with hippocampal asymmetry were identified from our institutional radiology database, including two patients with significant anatomic deformations. Manual hippocampal tracing was performed by experienced technologists on 3T MPRAGE images, measuring hippocampal volume up to the tectal plate, excluding the hippocampal tail. The same images were processed using NeuroQuant and FreeSurfer software. Ten subjects underwent repeated manual hippocampal tracings by two additional technologists blinded to previous results to evaluate consistency. Ten patients with two clinical MRI studies had volume measurements repeated using NeuroQuant and FreeSurfer. Results: FreeSurfer raw volumes were significantly lower than NeuroQuant (P ' 0.001, right and left), and hippocampal asymmetry estimates were lower for both automatic methods than manual tracing (P ' 0.0001). Differences remained significant after scaling volumes to age, gender, and scanner matched normative percentiles. Volume reproducibility was fair (0.4–0.59) for manual tracing, and excellent ('0.75) for both automated methods. Asymmetry index reproducibility was excellent ('0.75) for manual tracing and FreeSurfer segmentation and fair (0.4–0.59) for NeuroQuant segmentation. Both automatic segmentation methods failed on the two cases with anatomic deformations. Segmentation errors were visually identified in 25 NeuroQuant and 27 FreeSurfer segmentations, and nine (18%) NeuroQuant and six (12%) FreeSurfer errors were judged clinically significant. Interpretation: Automated hippocampal volumes are more reproducible than hand-traced hippocampal volumes. However, these methods fail in some cases, and significant segmentation errors can occur.
AB - Objective: To rigorously compare automated atlas-based and manual tracing hippocampal segmentation for accuracy, repeatability, and clinical acceptability given a relevant range of imaging abnormalities in clinical epilepsy. Methods: Forty-nine patients with hippocampal asymmetry were identified from our institutional radiology database, including two patients with significant anatomic deformations. Manual hippocampal tracing was performed by experienced technologists on 3T MPRAGE images, measuring hippocampal volume up to the tectal plate, excluding the hippocampal tail. The same images were processed using NeuroQuant and FreeSurfer software. Ten subjects underwent repeated manual hippocampal tracings by two additional technologists blinded to previous results to evaluate consistency. Ten patients with two clinical MRI studies had volume measurements repeated using NeuroQuant and FreeSurfer. Results: FreeSurfer raw volumes were significantly lower than NeuroQuant (P ' 0.001, right and left), and hippocampal asymmetry estimates were lower for both automatic methods than manual tracing (P ' 0.0001). Differences remained significant after scaling volumes to age, gender, and scanner matched normative percentiles. Volume reproducibility was fair (0.4–0.59) for manual tracing, and excellent ('0.75) for both automated methods. Asymmetry index reproducibility was excellent ('0.75) for manual tracing and FreeSurfer segmentation and fair (0.4–0.59) for NeuroQuant segmentation. Both automatic segmentation methods failed on the two cases with anatomic deformations. Segmentation errors were visually identified in 25 NeuroQuant and 27 FreeSurfer segmentations, and nine (18%) NeuroQuant and six (12%) FreeSurfer errors were judged clinically significant. Interpretation: Automated hippocampal volumes are more reproducible than hand-traced hippocampal volumes. However, these methods fail in some cases, and significant segmentation errors can occur.
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U2 - 10.1002/acn3.50885
DO - 10.1002/acn3.50885
M3 - Article
C2 - 31489797
AN - SCOPUS:85071852626
VL - 6
SP - 1807
EP - 1814
JO - Annals of Clinical and Translational Neurology
JF - Annals of Clinical and Translational Neurology
SN - 2328-9503
IS - 9
ER -