A positioning apparatus for positioning a patient in a medical imaging system, the positioning apparatus comprising at least one base unit, wherein a base unit of the at least one base unit comprises at least one driving unit, a table assembly configured to hold the patient, and at least one supporting unit connecting the table assembly and the base unit. A supporting unit of the at least one supporting unit is positioned below the table assembly to a substantial middle portion of the table assembly, wherein the at least one driving unit is configured to drive the supporting unit in a horizontal direction with respect to the base unit to move a portion of the table assembly into a scanning unit of the medical imaging system for positioning the patient.
