KMID : 0880420190200071195
|
|
Korean Journal of Radiology 2019 Volume.20 No. 7 p.1195 ~ p.1206
|
|
Accuracy of Model-Based Iterative Reconstruction for CT Volumetry of Part-Solid Nodules and Solid Nodules in Comparison with Filtered Back Projection and Hybrid Iterative Reconstruction at Various Dose Settings: An Anthropomorphic Chest Phantom Study
|
|
Kim Seung-Kwan
Kim Cherry Lee Ki-Yeol Cha Jae-Hyung Lim Hyun-Ju Kang Eun-Young Oh Yu-Whan
|
|
Abstract
|
|
|
Objective: To investigate the accuracy of model-based iterative reconstruction (MIR) for volume measurement of part-solid nodules (PSNs) and solid nodules (SNs) in comparison with filtered back projection (FBP) or hybrid iterative reconstruction (HIR) at various radiation dose settings.
Materials and Methods: CT scanning was performed for eight different diameters of PSNs and SNs placed in the phantom at five radiation dose levels (120 kVp/100 mAs, 120 kVp/50 mAs, 120 kVp/20 mAs, 120 kVp/10 mAs, and 80 kVp/10 mAs). Each CT scan was reconstructed using FBP, HIR, or MIR with three different image definitions (body routine level 1 [IMR-R1], body soft tissue level 1 [IMR-ST1], and sharp plus level 1 [IMR-SP1]; Philips Healthcare). The SN and PSN volumes including each solid/ground-glass opacity portion were measured semi-automatically, after which absolute percentage measurement errors (APEs) of the measured volumes were calculated. Image noise was calculated to assess the image quality.
Results: Across all nodules and dose settings, the APEs were significantly lower in MIR than in FBP and HIR (all p < 0.01). The APEs of the smallest inner solid portion of the PSNs (3 mm) and SNs (3 mm) were the lowest when MIR (IMR-R1 and IMR-ST1) was used for reconstruction for all radiation dose settings. (IMR-R1 and IMR-ST1 at 120 kVp/100 mAs, 1.06 ¡¾ 1.36 and 8.75 ¡¾ 3.96, p < 0.001; at 120 kVp/50 mAs, 1.95 ¡¾ 1.56 and 5.61 ¡¾ 0.85, p = 0.002; at 120 kVp/20 mAs, 2.88 ¡¾ 3.68 and 5.75 ¡¾ 1.95, p = 0.001; at 120 kVp/10 mAs, 5.57 ¡¾ 6.26 and 6.32 ¡¾ 2.91, p = 0.091; at 80 kVp/10 mAs, 5.84 ¡¾ 1.96 and 6.90 ¡¾ 3.31, p = 0.632). Image noise was significantly lower in MIR than in FBP and HIR for all radiation dose settings (120 kVp/100 mAs, 3.22 ¡¾ 0.66; 120 kVp/50 mAs, 4.19 ¡¾ 1.37; 120 kVp/20 mAs, 5.49 ¡¾ 1.16; 120 kVp/10 mAs, 6.88 ¡¾ 1.91; 80 kVp/10 mAs, 12.49 ¡¾ 6.14; all p < 0.001).
Conclusion: MIR was the most accurate algorithm for volume measurements of both PSNs and SNs in comparison with FBP and HIR at low-dose as well as standard-dose settings. Specifically, MIR was effective in the volume measurement of the smallest PSNs and SNs.
|
|
KEYWORD
|
|
Lung neoplasm, Phantoms, imaging, Multidetector computed tomography, Radiation dosage
|
|
FullTexts / Linksout information
|
|
|
|
Listed journal information
|
|
|
|