Comparison between Conventional Unenhanced and Virtual Unenhanced Imaging of Hepatopancreaticobiliary System with Third-Generation Dual-Source Dual-Energy CT—An Observational Study

Abstract Objectives The aims of our study were to assess the comparability of conventional unenhanced images (CUIs) of hepatopancreaticobiliary system with virtual unenhanced images (VUIs) derived from arterial and portal venous phases acquired in a third-generation, dual-source, dual-energy CT (DECT), and also to assess the best dataset among these VUIs. We also calculated the radiation effective dose (ED) reduction by eliminating noncontrast acquisition. Materials and Methods 60 patients were included in our study. Unenhanced images in single energy and contrast-enhanced images in dual-energy mode were acquired. Arterial virtual unenhanced (AVU) and portal virtual unenhanced (PVU) images were generated and compared with CUI, using both objective and subjective methods. The ED was calculated separately for each phase. Statistical significance between difference in mean attenuation values were analyzed using ANOVA and unpaired student t-test. Results In our study, the difference in mean attenuation of liver, spleen, and pancreas between the three phases—CU, AVU, and PVU—were insignificant with p-value > 0.05. This indicates that the values were comparable. Among the VUI, AVU images were statistically superior in image quality. Elimination of noncontrast CT from triple phase abdominal imaging can achieve an average ED reduction of 39%. Conclusions We conclude that VUI generated in third-generation, dual-source DECT has diagnostic image quality and can replace the CUI in triple-phase studies, with a mean ED reduction by 39%. The VUI obtained from arterial phase is superior to those obtained from portal venous phase.

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Trends in radiation dose and image quality for pediatric patients with a multidetector CT and a third-generation dual-source dual-energy CT

La radiologia medica ◽

10.1007/s11547-019-01037-5 ◽

2019 ◽

Vol 124 (8) ◽

pp. 745-752 ◽

Cited By ~ 4

Author(s):

Andrea Agostini ◽

Alberto Mari ◽

Cecilia Lanza ◽

Nicolo’ Schicchi ◽

Alessandra Borgheresi ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Pediatric Patients ◽

Multidetector Ct ◽

Dual Energy ◽

Dual Energy Ct ◽

Third Generation ◽

Dual Source

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Single- and dual-energy CT pulmonary angiography using second- and third-generation dual-source CT systems: comparison of radiation dose and image quality

European Radiology ◽

10.1007/s00330-018-5982-1 ◽

2019 ◽

Vol 29 (9) ◽

pp. 4603-4612 ◽

Cited By ~ 7

Author(s):

Lukas Lenga ◽

Franziska Trapp ◽

Moritz H. Albrecht ◽

Julian L. Wichmann ◽

Addison A. Johnson ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Pulmonary Angiography ◽

Dual Energy ◽

Dual Energy Ct ◽

Third Generation ◽

Dual Source Ct ◽

Ct Pulmonary Angiography ◽

Dual Source

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Virtual unenhanced imaging of the liver with third-generation dual-source dual-energy CT and advanced modeled iterative reconstruction

European Journal of Radiology ◽

10.1016/j.ejrad.2016.04.012 ◽

2016 ◽

Vol 85 (7) ◽

pp. 1257-1264 ◽

Cited By ~ 27

Author(s):

Carlo N. De Cecco ◽

Giuseppe Muscogiuri ◽

U. Joseph Schoepf ◽

Damiano Caruso ◽

Julian L. Wichmann ◽

...

Keyword(s):

Iterative Reconstruction ◽

Dual Energy ◽

Dual Energy Ct ◽

Third Generation ◽

Dual Source ◽

Virtual Unenhanced

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Assessment of thoracic disk herniation by using virtual noncalcium dual-energy CT in comparison with standard grayscale CT

European Radiology ◽

10.1007/s00330-021-07989-5 ◽

2021 ◽

Author(s):

Vitali Koch ◽

Ibrahim Yel ◽

Leon D. Grünewald ◽

Sebastian Beckers ◽

Iris Burck ◽

...

Keyword(s):

Image Quality ◽

Diagnostic Accuracy ◽

Dual Energy ◽

Spinal Nerve ◽

Dual Energy Ct ◽

Third Generation ◽

Spinal Nerve Root ◽

Disk Herniation ◽

Diagnostic Confidence ◽

Dual Source

Abstract Objectives To determine the diagnostic accuracy of dual-energy CT (DECT) virtual noncalcium (VNCa) reconstructions for assessing thoracic disk herniation compared to standard grayscale CT. Methods In this retrospective study, 87 patients (1131 intervertebral disks; mean age, 66 years; 47 women) who underwent third-generation dual-source DECT and 3.0-T MRI within 3 weeks between November 2016 and April 2020 were included. Five blinded radiologists analyzed standard DECT and color-coded VNCa images after a time interval of 8 weeks for the presence and degree of thoracic disk herniation and spinal nerve root impingement. Consensus reading of independently evaluated MRI series served as the reference standard, assessed by two separate experienced readers. Additionally, image ratings were carried out by using 5-point Likert scales. Results MRI revealed a total of 133 herniated thoracic disks. Color-coded VNCa images yielded higher overall sensitivity (624/665 [94%; 95% CI, 0.89–0.96] vs 485/665 [73%; 95% CI, 0.67–0.80]), specificity (4775/4990 [96%; 95% CI, 0.90–0.98] vs 4066/4990 [82%; 95% CI, 0.79–0.84]), and accuracy (5399/5655 [96%; 95% CI, 0.93–0.98] vs 4551/5655 [81%; 95% CI, 0.74–0.86]) for the assessment of thoracic disk herniation compared to standard CT (all p < .001). Interrater agreement was excellent for VNCa and fair for standard CT (ϰ = 0.82 vs 0.37; p < .001). In addition, VNCa imaging achieved higher scores regarding diagnostic confidence, image quality, and noise compared to standard CT (all p < .001). Conclusions Color-coded VNCa imaging yielded substantially higher diagnostic accuracy and confidence for assessing thoracic disk herniation compared to standard CT. Key Points • Color-coded VNCa reconstructions derived from third-generation dual-source dual-energy CT yielded significantly higher diagnostic accuracy for the assessment of thoracic disk herniation and spinal nerve root impingement compared to standard grayscale CT. • VNCa imaging provided higher diagnostic confidence and image quality at lower noise levels compared to standard grayscale CT. • Color-coded VNCa images may potentially serve as a viable imaging alternative to MRI under circumstances where MRI is unavailable or contraindicated.

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Comparison of dose and image quality of dual-energy CT pulmonary angiografy on 2nd and 3 rd generation dual-source scanners

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren ◽

10.1055/s-0035-1550807 ◽

2015 ◽

Vol 187 (S 01) ◽

Author(s):

S Fischer ◽

N Schultheis ◽

P Dewes ◽

J Scholtz ◽

M Kerl ◽

...

Keyword(s):

Image Quality ◽

Dual Energy ◽

Dual Energy Ct ◽

Dual Source

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Threshold-dependent iodine imaging and spectral separation in a whole-body photon-counting CT system

European Radiology ◽

10.1007/s00330-021-07786-0 ◽

2021 ◽

Author(s):

S. Sawall ◽

L. Klein ◽

E. Wehrse ◽

L. T. Rotkopf ◽

C. Amato ◽

...

Keyword(s):

Image Quality ◽

Photon Counting ◽

Dual Energy ◽

Whole Body ◽

Dual Energy Ct ◽

Post Mortem ◽

Tube Voltage ◽

Spectral Separation ◽

Dual Source ◽

Noise Ratio

Abstract Objective To evaluate the dual-energy (DE) performance and spectral separation with respect to iodine imaging in a photon-counting CT (PCCT) and compare it to dual-source CT (DSCT) DE imaging. Methods A semi-anthropomorphic phantom extendable with fat rings equipped with iodine vials is measured in an experimental PCCT. The system comprises a PC detector with two energy bins (20 keV, T) and (T, eU) with threshold T and tube voltage U. Measurements using the PCCT are performed at all available tube voltages (80 to 140 kV) and threshold settings (50–90 keV). Further measurements are performed using a conventional energy-integrating DSCT. Spectral separation is quantified as the relative contrast media ratio R between the energy bins and low/high images. Image noise and dose-normalized contrast-to-noise ratio (CNRD) are evaluated in resulting iodine images. All results are validated in a post-mortem angiography study. Results R of the PC detector varies between 1.2 and 2.6 and increases with higher thresholds and higher tube voltage. Reference R of the EI DSCT is found as 2.20 on average overall phantoms. Maximum CNRD in iodine images is found for T = 60/65/70/70 keV for 80/100/120/140 kV. The highest CNRD of the PCCT is obtained using 140 kV and is decreasing with decreasing tube voltage. All results could be confirmed in the post-mortem angiography study. Conclusion Intrinsically acquired DE data are able to provide iodine images similar to conventional DSCT. However, PCCT thresholds should be chosen with respect to tube voltage to maximize image quality in retrospectively derived image sets. Key Points • Photon-counting CT allows for the computation of iodine images with similar quality compared to conventional dual-source dual-energy CT. • Thresholds should be chosen as a function of the tube voltage to maximize iodine contrast-to-noise ratio in derived image sets. • Image quality of retrospectively computed image sets can be maximized using optimized threshold settings.

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