Comparing CNR, SNR, and Image Quality of CT Images Reconstructed with Soft Kernel, Standard Kernel, and Standard Kernel plus ASIR 30% Techniques

Priya Bhosale



Compare effect of soft kernel (SK) and 30% adaptive statistical iterative reconstruction (ASIR) and standard kernel (StK) techniques on image quality.


Materials and Methods:

Three radiologists blinded to the type of reconstruction kernel used, independently reviewed 2.5mm-thick- axial abdominal CT-scans performed for 66-randomly selected patients, optimized for oncologic imaging. The filtered-back-projection images were reconstructed using: SK, ASIR 30% and StK. The Contrast to noise ratio (CNRs) and Signal to noise ration (SNRs) were calculated. The visibility and sharpness of abdominal structures were rated (qualitatively). Summary of pair-wise comparisons among series for CNRs and SNRs were performed. Estimates and standard-error were based on a linear mixed model. P values were adjusted using the Tukey-Kramer method to control overall type I error rate.



Image series reconstructed with SK or ASIR had higher CNRs than those with StK alone (P < .009 and .002, respectively). Qualitatively images reconstructed with ASIR or SK were better than with the StK (P < .05). SK produced significantly fewer artifacts than ASIR 30%. There was no difference in the SNR among series.



Images reconstructed with SK or ASIR had better image quality than StK. Scanners that cannot use ASIR may benefit from using the SK technique to improve image quality.


ASIR 30%, Soft kernel, Standard Kernel, CNR, SNR, Noise

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