How far can the radiation dose be lowered in head CT with iterative reconstruction? Analysis of imaging quality and diagnostic accuracy.

Objective: To evaluate the imaging quality of head CT at lowered radiation dose by combining filtered back projection (FBP) and iterative reconstruction (IR) algorithms.

Methods: Experimental group A (n = 66) underwent CT with 43 % tube current reduction, and group B (n = 58) received an equivalent reduced dose by lowering the tube voltage. An age- and sex-matched control group (n = 72) receiving the conventional radiation dose was retrospectively collected.