1. Introduction

2. Identification of SNR Hi shells

3. Supernova Remnants with Fast-Expanding Hi Shells
3.1. W44 (G34.7 - 0.4)
3.2. G54.4 - 0.3 (HC 40)

4. Discussion
4.1. Properties of Hi SNRs
4.2. Visibility and Statistics of Hi SNRs

5. Summary