An investigation of the iterative reconstruction method iDose(4) on a Philips CT Brilliance 64 using a Catphan 600 phantom

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


The number of CT examinations giving a relatively high patient exposure is increasing. It is therefore important to optimize the imaging conditions at these investigations. Many steps have been taken to reduce the radiation doses in CT examinations. Currently much work is related to iterative image reconstruction methods as alternative to the filtered back projection method. The aim of this work was to evaluate quality parameters in images from a CT (Philips Brilliance 64) equipped with the iterative reconstruction method iDose(4) using a Catphan 600 phantom with and without body simulating ring. CT scans using abdomen protocol were taken with various tube currents and tube voltage and keeping collimation and pitch unchanged for all scans. All collected data were reconstructed with different levels of iDose(4) (Level 2, 4, 6) and traditional filtered back projection. Image quality parameters were evaluated using AutoQA Lite (TM) (Version 2.3 2007 Iris QA, LLC). Results from the study shows that the iterative reconstruction method decreases the noise with 15-45% compared with filtered back projection depending on which level of iDose(4) is used. The percentage reduction in noise level is the same with and without body simulating ring. Low contrast was improved with iDose(4) and spatial resolution is only marginally affected by the method of reconstruction. However by reducing the image noise, the detectability can be improved. Our conclusion is that there is great potential to reduce the noise and thereby improve the image quality by using iterative reconstruction methods. This can also be used to lower radiation dose and maintain image quality or improve image quality.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Radiology, Nuclear Medicine and Medical Imaging


  • MSCT, image quality, iDose(4), iterative
Original languageEnglish
Title of host publicationMedical Imaging 2012: Physics of Medical Imaging
Publication statusPublished - 2012
Publication categoryResearch
EventConference on Medical Imaging - Physics of Medical Imaging, 2012 - San Diego, CA, United States
Duration: 2012 Feb 52012 Feb 8

Publication series

ISSN (Print)1996-756X
ISSN (Electronic)0277-786X


ConferenceConference on Medical Imaging - Physics of Medical Imaging, 2012
CountryUnited States
CitySan Diego, CA