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Purpose: To evaluate the performance of a novel camera-based breathing navigation system in respiratory-triggered (CRT) 3D-magnetic resonance cholangiopancreatography (MRCP) at 3T MRI., Methods: Two 3D-MRCP data sets were acquired subsequently within one imaging session with traditional respiratory belt- (BRT) or camera- (CRT) based triggering in 28 patients. Overall image quality, blurring, motion artifacts and discernibility of the pancreaticobiliary tree (PBT) structures were scored on a 4-point scale retrospectively by 2 radiologists. The contrast ratio between the common bile duct and its adjacent tissue was measured by region-of-interest (ROI) analysis. The signal intensity increase at the duct boundaries was quantified by line profiles to objectify blurring and motion artifacts. The extracted respiratory signal curves were analyzed for signal quality and trigger timing., Results: Total scan time was 72 s for both acquisitions. CRT yielded significantly better ratings in image quality, background suppression, blurring and discernibility of PBT structures compared to BRT. Contrast ratios were significantly higher in CRT (0.94 ± 0.03) than in BRT (0.93 ± 0.03) exams; paired t test P = 0.0017. Line profile slopes through the common bile duct revealed significantly higher values in CRT (42.23 ± 8.74% of maximum intensity/mm) compared to BRT (36.06 ± 8.96% of maximum intensity/mm; paired t test P < 0.0001). Camera-derived respiratory signal curves showed a higher SNR, lower standard deviation of the signal amplitude and less incorrect triggering than the respiratory belt-derived respiratory signal curves., Conclusion: Camera-based respiratory triggering significantly improves image quality of 3D-MRCP compared to conventional respiratory belt triggering., (Copyright © 2019. Published by Elsevier B.V.)

Objectives: To compare the image quality between compressed sensing (CS) 3D-magnetic resonance cholangiopancreatography (MRCP) using respiratory-triggered (RT) and breath-hold (BH) acquisitions and 2D single-shot breath-hold (SSBH) MRCP at 3 T MRI., Methods: 53 datasets were retrospectively assessed. 3D-MRCP with CS (RT-CS10, BH-CS24) and 2D-SSBH MRCP were acquired. Overall image quality, blurring/motion artifacts and discernibility of the pancreaticobiliary tree (PBT) structures were scored on a 4-point scale by 2 radiologists. The contrast ratio between the common bile duct and its adjacent tissue was measured by region-of-interest (ROI) analysis. Signal intensity increase at the boundaries of the ducts was quantified by line profiles to objectively characterize blurring and motion artifacts., Results: Total scan duration was 17 s for BH-CS24, 1m12 s for 2D-SSBH and 3m48 s for RT-CS10. Images acquired with CS were consistently rated superior in terms of image quality, background suppression, blurring and discernibility of PBT structures compared to 2D-SSBH images. RT-CS10 was superior to BH-CS24 for all ratings except for blurring. Objective analysis yielded the highest contrast ratio for RT-CS10 (0.91 ± 0.04) followed by BH-C24 (0.88 ± 0.05) and 2D-SSBH (0.85 ± 0.06); one-way ANOVA P < 0.0001. The line-profile slope through the CBD was significantly higher in BH-CS24 (37.91 ± 6.38% of maximum intensity/mm) compared to RT-CS10 (29.46 ± 8.17% of maximum intensity/mm) and on par with 2D-SSBH (35.8 ± 12.30% of maximum intensity/mm); one-way-ANOVA P = 0.017., Conclusion: CS allows acquisition of volumetric image data with improved image quality compared to SSBH. CS24 yields substantial gains in acquisition speed while robust towards artifacts, enabling diagnostic image quality with a single breath-hold acquisition., (Copyright © 2019 Elsevier B.V. All rights reserved.)