Update README.md

README.md

@@ -27,3 +27,5 @@ Additional IDPs extracted in this study are quantitative susceptibility mapping
 * **Arterial Spin Labelling (ASL).**
 This sequence was not included in UKB at the time of this study. See `ASL_pipeline` for details on preprocessing pipeline and IDP extraction.
 
+## Useful resources
+[UK Biobank Brain Imaging Documentation](https://biobank.ndph.ox.ac.uk/showcase/showcase/docs/brain_mri.pdf)