Zhao XM, Wang M, Wu RZ, Dharaiya E, Feng F, Li ML, You H, Wang Y, Wang YN, Jin ZY. Dual-layer spectral detector CT monoenergetic reconstruction improves image quality of non-contrast cerebral CT as compared with conventional single energy CT.
Eur J Radiol 2018;
103:131-138. [PMID:
29803379 DOI:
10.1016/j.ejrad.2018.04.015]
[Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/01/2018] [Accepted: 04/12/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE
To investigate and compare image quality of monoenergetic reconstructions from spectral NCCT to conventional 120 kVp images acquired at a similar dose.
MATERIALS AND METHODS
Patients undergoing NCCT on a dual-layer spectral detector CT (n = 30) and a conventional CT (n = 30) were enrolled in the study. The spectral detector CT data was reconstructed at monoenergetic images from 40 to 140 keV in 5-keV increments and 65-70 keV in 1-keV increments (Group A1) and using single energy CT equivalent reconstruction (Group A2). The reference conventional 120kVp images (Group B) were acquired using a standard-of-care protocol with the same radiation dose. We evaluated the image quality of monoenergetic images and determined the optimal keV level using HU attenuation, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), artifact evaluation in posterior fossa by placing region-of-interest (ROI) and subjective image score by 2 radiologists independently using a 4-point scale (1-excellent, 4-undiagnostic).
RESULTS
The SNR and subjective image score were optimal at 66-70keV, while monoenergetic 68 keV images with a higher SNR (18.48 ± 1.94, 15.55 ± 1.56 and 14.33 ± 1.38 for Group 68keV, A2 and B respectively, p < 0.001), CNR (4.09 ± 0.65, 3.43 ± 0.56 and 3.52 ± 0.55 for Group 68keV, A2 and B respectively, p < 0.001) and a lower noise (1.80 ± 0.19, 2.11 ± 0.19 and 2.25 ± 0.25 for Group 68keV, A2 and B respectively, p < 0.001).
CONCLUSION
Spectral NCCT monoenergetic reconstructions at 68 keV improve image quality and reduce artifact compared to conventional single energy CT without radiation dose penalty.
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