The reconstruction algorithm , adaptive statstical iterative reconstruction(ASIR) , has been introduced that effectively increases image quality by reducing noise .
Iterative recontruction methods are different from filter back projection (FBP) technique that has been used for redusing image noise. In FBP, projection data are filtered and then pushed back along ray paths to form image pixels.
Iterative reconstruction is more straightforward and complex as well , computing image data iteratively via statistical reconstruction algorithms and algebraic reconstruction techniques that predict the characteristics of missing...
Description of activity and work performed
A GE Brightspeed Elite 16 scanner was used in the imaging department at Agia Sofia General paediatric hospital.
A phantom study was performed , in order to assess the effect of ASIR on dose and image quality. To evaluate dose reduction limits , the phantom was scanned in increments of increased Noise index (mA decreasement using AEC ),in balance with ASIR reconstraction to maintain noise equivalence of the 0% ASIR image.
Two hundred and twelve patients from 0,5 to 15 years old 9,1± 4,1underwenthead ,...
Conclusion and recommendations
For ASIR from 0%-100% the average value of CTDIvolwas estimated, for different age groups for the examinations under consideration. A significant reduction of dose, from 21,2 to 82,3 %, was found, according to the degree of ASIR and the protocol. For head examination, the use of 60% instead of 40% ASIR leads to an average dose reduction of 28,7%, while for chest and abdomen examinations the use of 80% instead of 60% ASIR, the average dose reduction is 22,3% and 27,3 % respectively. Regarding...
M. Chasiotou; Agia Paraskevi - Athens/GR - nothing to disclose V. G. Syrgiamiotis; Athens/GR - nothing to disclose D. T. Makri; Athens/GR - nothing to disclose
1.Lowering the Dose in Head CT Using Adaptive Statistical Iterative Reconstruction K. Kilic , G Erbas , M. Guryildirim , M. Arac , E.Ligit and B . Coskun . American Journal of Neuroradiology , October 2011, 32(9)1578-1582
2.Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination.Pediatr Radiol2014 Aug;44(8):997-1003
3.Katsura M, Sato J, Akahane M et al. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: image quality assessment in the cervicothoracic region. Eur J...