scholarly journals Dual Energy on Dual Source CT in Abdominal Imaging

2020 ◽  
Author(s):  
Varchetta Francesco ◽  
Orlando Giuseppe ◽  
Laurenza Francesco ◽  
Rengo Alessandro ◽  
Danzi Roberta ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Reduction ◽  
Absorbed Dose ◽  
Dual Energy ◽  
Data Sets ◽  
Diagnostic Quality ◽  
Portal Phase ◽  
Phase Images ◽  
Dual Source ◽  
The Difference

Establish whether virtual non-contrast images can replace real non-contrast images, avoiding the preliminary scan, thus saving the patient dose. Forty-one patients were studied on a second-generation dual-source scanner, triphasic were applied on all patients, arterial and venous phase was acquired in dual-energy. HU values of TNC and VNC scans were compared through ROI on liver, spleen, kidneys, aorta, muscle, and fat. Qualitative analysis of the data sets was performed by four readers and the values from 1 to 4 (1. poor, 2. fair, 3. good, 4. excellent.) were assigned to define the diagnostic quality of the images. Then the absorbed dose ratios between the virtual images and the pre-contrast and portal phase images were compared. HU values were analyzed with the t-test and the difference was statistically significant P<0.0001. Image quality was evaluated as excellent or good in 91,3% of TNC and 81,6% of VNC. At last, VNC showed a sensitive dose reduction -46% compared to conventional triphasic protocol. Overall VNC has shown a good image quality comparable to TNC. The dose reduction obtained from the extraction of images without iodine, avoiding further scans, suggests the use of the dual-energy protocol in many exams.

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

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.

scholarly journals Simulated Radiation Dose Reduction in Whole-Body CT on a 3rd Generation Dual-Source Scanner: An Intraindividual Comparison

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Andreas S. Brendlin ◽  
Moritz T. Winkelmann ◽  
Phuong Linh Do ◽  
Vincent Schwarze ◽  
Felix Peisen ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Whole Body ◽  
Reference Standard ◽  
Diagnostic Confidence ◽  
Effective Radiation Dose ◽  
Intraindividual Comparison ◽  
Dual Source ◽  
Effective Radiation

To evaluate the effect of radiation dose reduction on image quality and diagnostic confidence in contrast-enhanced whole-body computed tomography (WBCT) staging. We randomly selected March 2016 for retrospective inclusion of 18 consecutive patients (14 female, 60 ± 15 years) with clinically indicated WBCT staging on the same 3rd generation dual-source CT. Using low-dose simulations, we created data sets with 100, 80, 60, 40, and 20% of the original radiation dose. Each set was reconstructed using filtered back projection (FBP) and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 1–5, resulting in 540 datasets total. ADMIRE 2 was the reference standard for intraindividual comparison. The effective radiation dose was calculated using commercially available software. For comparison of objective image quality, noise assessments of subcutaneous adipose tissue regions were performed automatically using the software. Three radiologists blinded to the study evaluated image quality and diagnostic confidence independently on an equidistant 5-point Likert scale (1 = poor to 5 = excellent). At 100%, the effective radiation dose in our population was 13.3 ± 9.1 mSv. At 20% radiation dose, it was possible to obtain comparably low noise levels when using ADMIRE 5 (p = 1.000, r = 0.29). We identified ADMIRE 3 at 40% radiation dose (5.3 ± 3.6 mSv) as the lowest achievable radiation dose with image quality and diagnostic confidence equal to our reference standard (p = 1.000, r > 0.4). The inter-rater agreement for this result was almost perfect (ICC ≥ 0.958, 95% CI 0.909–0.983). On a 3rd generation scanner, it is feasible to maintain good subjective image quality, diagnostic confidence, and image noise in single-energy WBCT staging at dose levels as low as 40% of the original dose (5.3 ± 3.6 mSv), when using ADMIRE 3.

Split-Bolus Portal Venous Phase Dual-Energy CT Urography: Protocol Design, Image Quality, and Dose Reduction

2015 ◽  
Vol 205 (5) ◽  
pp. W492-W501 ◽  
Author(s):  
Chiao-Yun Chen ◽  
Jui-Sheng Hsu ◽  
Twei-Shiun Jaw ◽  
Ming-Chen Paul Shih ◽  
Lo-Jeh Lee ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Reduction ◽  
Dual Energy ◽  
Protocol Design ◽  
Dual Energy Ct ◽  
Ct Urography ◽  
Portal Venous Phase ◽  
Venous Phase

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

2019 ◽  
Vol 124 (8) ◽  
pp. 745-752 ◽  
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

scholarly journals Virtual monochromatic imaging in dual-source dual-energy CT: Radiation dose and image quality

2011 ◽  
Vol 38 (12) ◽  
pp. 6371-6379 ◽  
Author(s):  
Lifeng Yu ◽  
Jodie A. Christner ◽  
Shuai Leng ◽  
Jia Wang ◽  
Joel G. Fletcher ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Virtual Monochromatic Imaging ◽  
Monochromatic Imaging ◽  
Ct Radiation ◽  
Dual Source

scholarly journals Optimization of Image Quality in Paediatric Computed Tomography

2021 ◽  
Author(s):  
Angjelina Protik
Keyword(s):  
Image Quality ◽  
Dose Reduction ◽  
Quantitative Data ◽  
Ct Image ◽  
Contrast Resolution ◽  
Diagnostic Quality ◽  
Advantages And Disadvantages ◽  
Phantom Studies ◽  
Ct Image Quality ◽  
The Impact

In this study the effects of ASIR™ and collimation on CT image quality (IQ) parameters were quantified. Catphan®600 phantom studies were performed on a GE HD750 64-slice scanner to investigate the impact of collimation 0.625mm vs. 5mm on the overall IQ. For noise and dose reduction ASIR™ was tested on 0.625mm collimation. The varying %ASIR™, scanned at 150mA and variable kVp and 50% ASIR™ compared to FBP on wide kVp/mA range was used. Image noise, CT# accuracy and uniformity, spatial and contrast resolution, MTF, CNR and Wiener spectrum analysis were performed on 0.625mmAX slices, 5mmAXMPR and 2mmCORMPR. Incremental advantages and disadvantages were seen with stepwise increase in %ASIR™. The 50% ASIR™ was found to be optimal blend for diagnostic quality and has potential for dose reduction in paediatric CT. This quantitative data could be used to design ASIR™-enhanced protocols with consideration of diagnostic task, balancing image quality and radiation dose.

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