ROTATABLE FILTER FOR A PRE-SUBJECT CT COLLIMATOR HAVING MULTIPLE FILTERING PROFILES

摘要

The present invention is directed to a method and apparatus for CT data acquisition using a rotatable pre-subject filter having more than one filtering profile to control radiation exposure to a subject. The filter has one profile used to filter radiation when the radiation source is positioned above a subject and another profile that is used to filter radiation when the radiation source is positioned at a side of the subject.