Ultra-low-dose chest CT with iterative reconstruction does not alter anatomical image quality - 11/05/17
Abstract |
Purpose |
To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan.
Materials and methods |
Eighteen human cadavers had chest CT with one reference CT protocol (RP-CT; 120kVp/200mAs) and two protocols with dose reduction: low-dose-CT (LD-CT; 120kVp/40mAs) and ultra-low-dose CT (ULD-CT; 120kVp/10mAs). Data were reconstructed with filter-back-projection (FBP) for RP-CT and with FBP and IR (sinogram affirmed iterative reconstruction [SAFIRE®]) algorithm for LD-CT and ULD-CT. Volume CT dose index (CTDIvol) were recorded. The signal-to-noise (SNR), contrast-to-noise (CNR) ratios of LD-CT and ULD-CT and quantitative parameters were compared to RP-CT. Two radiologists reviewed the CT examinations assessed independently the quality of anatomical structures and expressed a confidence level using a 2-point scale (50% and 95%).
Results |
CTDIvol was 2.69 mGy for LD-CT (−80%; P<0.01) and 0.67 mGy for ULD-CT (−95%; P<0.01) as compared to 13.42 mGy for RP-CT. SNR and CNR were significantly decreased (P<0.01) for LD-CT and ULD-CT, but IR improved these values satisfactorily. No significant differences were observed for quantitative measurements. Radiologists rated excellent/good the RP-CT and LD-CT images, whereas good/fair the ULD-CT images. Confidence level for subjective anatomical analysis was 95% for all protocols.
Conclusions |
Dose reduction with a dose lower than 1 mGy, used in conjunction with IR allows performing chest CT examinations that provide a high quality of anatomical structures.
Le texte complet de cet article est disponible en PDF.Keywords : Ultra-low-dose chest CT, Sinogram affirmed iterative reconstruction, Image quality, Dose reduction, Safire®
Plan
Vol 97 - N° 11
P. 1131-1140 - novembre 2016 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.