Computed Tomography (CT) is an important tool in diagnostic imaging. It plays a key role in diagnosis and intervention. Many advanced CT systems use wide detector arrays, multiple sources, andor very fast rotation speed, for important clinical applications (e.g., coronary artery and whole organ perfusion imaging). As a result, modern CT scanners are expensive and are typically used by major hospitals and clinics in developed countries. Over the past decades, CT systems or methods have been proposed assuming linear translation-based scanning.