Validity of linear measurements of the jaws using ultralow-dose MDCT and the iterative techniques of ASIR and MBIR
Journal Article
Al-Ekrish, Asma’a A. . 2016
Publication Online URL:
Magazine \ Newspaper:
International Journal of Computer Assisted Radiology and Surgery
Issue Number:
doi:10.1007/s11548-016-1419-y
Volume Number:
11
Pages:
1791–1801
Publication Abstract:
Purpose
To assess the comparability of linear measurements of dental implant sites recorded from multidetector computed tomography (MDCT) images obtained using standard-dose filtered backprojection (FBP) technique with those from various ultralow doses combined with FBP, adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR) techniques. The results of the study may contribute to MDCT dose optimization for dental implant site imaging.
Methods
MDCT scans of two cadavers were acquired using a standard reference protocol and four ultralow-dose test protocols (TP). The volume CT dose index of the different dose protocols ranged from a maximum of 30.48–36.71 mGy to a minimum of 0.44–0.53 mGy. All scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Linear measurements were recorded from standardized images of the jaws by two examiners. Intra- and inter-examiner reliability of the measurements were analyzed using Cronbach’s alpha and inter-item correlation. Agreement between the measurements obtained with the reference-dose/FBP protocol and each of the test protocols was determined with Bland–Altman plots and linear regression. Statistical significance was set at a P-value of 0.05.
Results
No systematic variation was found between the linear measurements obtained with the reference protocol and the other imaging protocols. The only exceptions were TP3/ASIR-50 (bone kernel) and TP4/ASIR-100 (bone and standard kernels). The mean measurement differences between these three protocols and the reference protocol were within ±0.1 mm, with the 95 % confidence interval limits being within the range of ±1.15 mm.
Conclusions
A nearly 97.5 % reduction in dose did not significantly affect the height and width measurements of edentulous jaws regardless of the reconstruction algorithm used.
Attachment:
