Does Iterative Reconstruction Improve Image Quality and Reduce Dose in Computed Tomography?
Rapid technological advancements in imaging techniques, such as the development of multidetector computed tomography, has resulted in a substantial rise in demand for CT examinations as a key diagnostic imaging modality over the past decade.
While the diagnostic benefits of CT are well-documented, the associated risks of increased exposure to ionizing radiation such as radiation-induced cancer has become an area of increasing concern. Radiation exposure from CT accounts for approximately two-thirds of all medical-related radiation worldwide, and recent studies have cited associated cumulative cancer risk from CT to be as high as 1.5%.
Several techniques, such as automatic tube current modulation, automatic tube voltage selection and
dynamically adjustable z-axis beam collimation, have been employed to reduce CT-associated
radiation dose, but the amount of dose reduction is limited if the FBP algorithm is used for image reconstruction.
The FBP algorithm has been the standard algorithm for image reconstruction in CT for many years, but it poses the limitation of producing possible streak artifacts and a notable increase in image noise
level if radiation dose is reduced exceedingly.
The re-emergence of IR techniques in CT recently offers a potential alternative that allows a reduction in radiation
dose while preserving image quality. IR algorithms were first considered for use in early
CT scanning back in the 1970’s, but were deemed unsuitable for clinical use due to the need for high
computational capacities in workstations and long reconstruction times.
Radiol Open J. 2016; 1(2): 42-54. doi: 10.17140/ROJ-1-108