RT Journal Article
SR Electronic
T1 High-Resolution Head CTA: A Prospective Patient Study Comparing Image Quality of Photon-Counting Detector CT and Energy-Integrating Detector CT
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1441
OP 1449
DO 10.3174/ajnr.A8342
VO 45
IS 10
A1 Diehn, Felix E.
A1 Zhou, Zhongxing
A1 Thorne, Jamison E.
A1 Campeau, Norbert G.
A1 Nagelschneider, Alex A.
A1 Eckel, Laurence J.
A1 Benson, John C.
A1 Madhavan, Ajay A.
A1 Bathla, Girish
A1 Lehman, Vance T.
A1 Huber, Nathan R.
A1 Baffour, Francis
A1 Fletcher, Joel G.
A1 McCollough, Cynthia H.
A1 Yu, Lifeng
YR 2024
UL http://www.ajnr.org/content/45/10/1441.abstract
AB BACKGROUND AND PURPOSE: Photon-counting detector CT (PCD-CT) is now clinically available and offers ultra-high–resolution (UHR) imaging. Our purpose was to prospectively evaluate the relative image quality and impact on diagnostic confidence of head CTA images acquired by using a PCD-CT compared with an energy-integrating detector CT (EID-CT).MATERIALS AND METHODS: Adult patients undergoing head CTA on EID-CT also underwent a PCD-CT research examination. For both CT examinations, images were reconstructed at 0.6 mm by using a matched standard resolution (SR) kernel. Additionally, PCD-CT images were reconstructed at the thinnest section thickness of 0.2 mm (UHR) with the sharpest kernel, and denoised with a deep convolutional neural network (CNN) algorithm (PCD-UHR-CNN). Two readers (R1, R2) independently evaluated image quality in randomized, blinded fashion in 2 sessions, PCD-SR versus EID-SR and PCD-UHR-CNN versus EID-SR. The readers rated overall image quality (1 [worst] to 5 [best]) and provided a Likert comparison score (−2 [significantly inferior] to 2 [significantly superior]) for the 2 series when compared side-by-side for several image quality features, including visualization of specific arterial segments. Diagnostic confidence (0–100) was rated for PCD versus EID for specific arterial findings, if present.RESULTS: Twenty-eight adult patients were enrolled. The volume CT dose index was similar (EID: 37.1 ± 4.7 mGy; PCD: 36.1 ± 4.0 mGy). Overall image quality for PCD-SR and PCD-UHR-CNN was higher than EID-SR (eg, PCD-UHR-CNN versus EID-SR: 4.0 ± 0.0 versus 3.0 ± 0.0 (R1), 4.9 ± 0.3 versus 3.0 ± 0.0 (R2); all P values < .001). For depiction of arterial segments, PCD-SR was preferred over EID-SR (R1: 1.0–1.3; R2: 1.0–1.8), and PCD-UHR-CNN over EID-SR (R1: 0.9–1.4; R2: 1.9–2.0). Diagnostic confidence of arterial findings for PCD-SR and PCD-UHR-CNN was significantly higher than EID-SR: eg, PCD-UHR-CNN versus EID-SR: 93.0 ± 5.8 versus 78.2 ± 9.3 (R1), 88.6 ± 5.9 versus 70.4 ± 5.0 (R2); all P values < .001.CONCLUSIONS: PCD-CT provides improved image quality for head CTA images compared with EID-CT, both when PCD and EID reconstructions are matched, and to an even greater extent when PCD-UHR reconstruction is combined with a CNN denoising algorithm.CNNconvolutional neural networkCNRcontrast to noise ratioCTDIvolvolume CT dose indexEIDenergy-integrating detectorHUHounsfield unitIRiterative reconstructionICCintraclass correlation coefficientPCDphoton-counting detectorQIRquantum iterative reconstructionQrquantitative regularSRstandard resolutionUHRultra–high resolutionVMIvirtual monoenergetic image