<qa>  What is the name of the brain scan performed during the Screening Period?11. Subjects with brain or subdural metastases are not eligible, unless they have completed local therapy and have discontinued the use of corticosteroids for this indication for at least 4 weeks prior to enrollment. Any symptoms attributed to brain metastases must be stable for at least 4 weeks prior to enrollment, and radiographic stability should be confirmed by comparing a brain scan CT with contrast or MRI with and without contrast performed during the Screening Period to a brain scan performed at least 4 weeks earlier using the same modality. 