Frontiers in Neuroscience (Oct 2020)

Automatic Skull Stripping of Rat and Mouse Brain MRI Data Using U-Net

  • Li-Ming Hsu,
  • Li-Ming Hsu,
  • Li-Ming Hsu,
  • Li-Ming Hsu,
  • Shuai Wang,
  • Shuai Wang,
  • Paridhi Ranadive,
  • Woomi Ban,
  • Woomi Ban,
  • Tzu-Hao Harry Chao,
  • Tzu-Hao Harry Chao,
  • Tzu-Hao Harry Chao,
  • Sheng Song,
  • Sheng Song,
  • Sheng Song,
  • Domenic Hayden Cerri,
  • Domenic Hayden Cerri,
  • Domenic Hayden Cerri,
  • Lindsay R. Walton,
  • Lindsay R. Walton,
  • Lindsay R. Walton,
  • Margaret A. Broadwater,
  • Margaret A. Broadwater,
  • Margaret A. Broadwater,
  • Sung-Ho Lee,
  • Sung-Ho Lee,
  • Sung-Ho Lee,
  • Dinggang Shen,
  • Dinggang Shen,
  • Dinggang Shen,
  • Yen-Yu Ian Shih,
  • Yen-Yu Ian Shih,
  • Yen-Yu Ian Shih

DOI
https://doi.org/10.3389/fnins.2020.568614
Journal volume & issue
Vol. 14

Abstract

Read online

Accurate removal of magnetic resonance imaging (MRI) signal outside the brain, a.k.a., skull stripping, is a key step in the brain image pre-processing pipelines. In rodents, this is mostly achieved by manually editing a brain mask, which is time-consuming and operator dependent. Automating this step is particularly challenging in rodents as compared to humans, because of differences in brain/scalp tissue geometry, image resolution with respect to brain-scalp distance, and tissue contrast around the skull. In this study, we proposed a deep-learning-based framework, U-Net, to automatically identify the rodent brain boundaries in MR images. The U-Net method is robust against inter-subject variability and eliminates operator dependence. To benchmark the efficiency of this method, we trained and validated our model using both in-house collected and publicly available datasets. In comparison to current state-of-the-art methods, our approach achieved superior averaged Dice similarity coefficient to ground truth T2-weighted rapid acquisition with relaxation enhancement and T2∗-weighted echo planar imaging data in both rats and mice (all p < 0.05), demonstrating robust performance of our approach across various MRI protocols.

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