Biomedical Image Registration, Domain Generalisation and Out-of-Distribution Analysis : MICCAI 2021 Challenges: MIDOG 2021, MOOD 2021, and Learn2Reg 2021, Held in Conjunction with MICCAI 2021, Strasbourg, France, September 27-October 1, 2021, Proceedings

This book constitutes three challenges that were held in conjunction with the 24th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2021, which was planned to take place in Strasbourg, France but changed to an online event due to the COVID-19 pandemic.

The peer-reviewed 18 long and 9 short papers included in this volume stem from the following three biomedical image analysis challenges:

• Mitosis Domain Generalization Challenge (MIDOG 2021),
• Medical Out-of-Distribution Analysis Challenge (MOOD 2021), and
• Learn2Reg (L2R 2021).

The challenges share the need for developing and fairly evaluating algorithms that increase accuracy, reproducibility and efficiency of automated image analysis in clinically relevant applications.