| The fact that he could see the sunspots with the naked eye and that he could make out the umbrae and penumbrae of the spots suggest that they must have been extremely large. |
| The fact that the Worcester monk could apparently distinguish the umbrae and penumbrae of the sunspots shows his amazing eye for detail. |
| However, this planning study was performed with a treatment planning system that does not correctly account for the increased lateral secondary electron transport in lung tissue, resulting in too steep beam penumbrae. |
| This unexpected finding could be of critical importance, particularly if the hyper C-2-DG uptake regions represent probable ischemic penumbrae. |
