scholarly journals Clinical Value of Energy Spectrum Curves of Dual-energy CT in Evaluating Pathological Grading of Gastric Adenocarcinoma

2019 ◽  
Author(s):  
Zhihua Lu ◽  
Suying Wu ◽  
Jianwei Chen ◽  
Chuan Yan ◽  
Yueming Li
Keyword(s):  
Gastric Cancer ◽  
Energy Spectrum ◽  
Gastric Adenocarcinoma ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Clinical Value ◽  
Pathological Differentiation ◽  
Dual Source ◽  
Venous Phase ◽  
Poorly Differentiated

Abstract Backgroud: Accurate diagnosis of cancer staging and pathological differentiation are critical for the formulation of individualized treatment and prognosis of gastric cancer. It is vital to explore non-invasive preoperative imaging techniques to evaluate the pathological differentiation degree of gastric cancer tissues, and provide better diagnostic basis and decision-making reference for treatment. The purpose of this study was to explore the clinical value of energy spectrum curves of dual-source dual-energy CT in the quantitative evaluation of different pathological grades of gastric adenocarcinoma. Methods: A total of 62 patients with 1 well, 25 moderately and 36 poorly differentiated gastric adenocarcinomas pathologically confirmed by surgery were collected, and they underwent dual-source dual-energy CT plain scanning and enhanced scanning before operation. Dual-Energy software was used to measure the slope of the energy spectrum curves (λ) in arterial and venous phases after image reconstruction. Patients were divided into two groups according to the pathological results, including well and moderately differentiated gastric adenocarcinoma group and poorly differentiated gastric adenocarcinoma group. Data of each group were analyzed by independent sample t-test. The receiver operating characteristic curve was plotted to evaluate the diagnostic efficiency of the corresponding parameters. Results: There were significant differences in λ values of 40-50keV, 40-60keV, 40-80keV, 40-90keV, 40-100keV, 40-120keV, 40-130keV, 40-140keV and 40-150keV energy ranges in venous phase between the well and moderately differentiated group and poorly differentiated group (P<0.05), but no significant differences in λ values of different energy ranges in arterial phase between the two groups (P>0.05). And the area under curve in 40-120keV energy range was the largest in venous phase. K40-120keV =2.69 was selected as the diagnostic threshold with the maximum Youden index, the sensitivity and specificity were 61.1% and 76%, respectively. Conclusion: The energy spectrum curve of dual-energy CT had certain diagnostic value in the quantitative evaluation of pathological grading of gastric adenocarcinoma.

scholarly journals Diagnostic accuracy of color-coded virtual noncalcium reconstructions derived from portal venous phase dual-energy CT in the assessment of lumbar disk herniation

2021 ◽  
Author(s):  
Vitali Koch ◽  
Moritz H. Albrecht ◽  
Leon D. Gruenewald ◽  
Ibrahim Yel ◽  
Katrin Eichler ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Disk Herniation ◽  
Lumbar Disk Herniation ◽  
Portal Venous Phase ◽  
Lumbar Disk ◽  
Contrast Enhanced ◽  
Dual Source ◽  
Venous Phase

Abstract Objectives To investigate the diagnostic accuracy of color-coded contrast-enhanced dual-energy CT virtual noncalcium (VNCa) reconstructions for the assessment of lumbar disk herniation compared to unenhanced VNCa imaging. Methods A total of 91 patients were retrospectively evaluated (65 years ± 16; 43 women) who had undergone third-generation dual-source dual-energy CT and 3.0-T MRI within an examination interval up to 3 weeks between November 2019 and December 2020. Eight weeks after assessing unenhanced color-coded VNCa reconstructions for the presence and degree of lumbar disk herniation, corresponding contrast-enhanced portal venous phase color-coded VNCa reconstructions were independently analyzed by the same five radiologists. MRI series were additionally analyzed by one highly experienced musculoskeletal radiologist and served as reference standard. Results MRI depicted 210 herniated lumbar disks in 91 patients. VNCa reconstructions derived from contrast-enhanced CT scans showed similar high overall sensitivity (93% vs 95%), specificity (94% vs 95%), and accuracy (94% vs 95%) for the assessment of lumbar disk herniation compared to unenhanced VNCa images (all p > .05). Interrater agreement in VNCa imaging was excellent for both, unenhanced and contrast-enhanced CT (κ = 0.84 vs κ = 0.86; p > .05). Moreover, ratings for diagnostic confidence, image quality, and noise differed not significantly between unenhanced and contrast-enhanced VNCa series (all p > .05). Conclusions Color-coded VNCa reconstructions derived from contrast-enhanced dual-energy CT yield similar diagnostic accuracy for the depiction of lumbar disk herniation compared to unenhanced VNCa imaging and therefore may improve opportunistic retrospective lumbar disk herniation assessment, particularly in case of staging CT examinations. Key Points • Color-coded dual-source dual-energy CT virtual noncalcium (VNCa) reconstructions derived from portal venous phase yield similar high diagnostic accuracy for the assessment of lumbar disk herniation compared to unenhanced VNCa CT series (94% vs 95%) with MRI serving as a standard of reference. • Diagnostic confidence, image quality, and noise levels differ not significantly between unenhanced and contrast-enhanced portal venous phase VNCa dual-energy CT series. • Dual-source dual-energy CT might have the potential to improve opportunistic retrospective lumbar disk herniation assessment in CT examinations performed for other indications through reconstruction of VNCa images.

Dual-Source Dual-Energy CT Portal Venous Phase Abdominal CT Scans in Large Body Habitus Patients

2018 ◽  
Vol 42 (6) ◽  
pp. 932-936 ◽  
Author(s):  
Vinit Baliyan ◽  
Hamed Kordbacheh ◽  
Jessica Serrao ◽  
Dushyant V. Sahani ◽  
Avinash R. Kambadakone
Keyword(s):  
Large Body ◽  
Dual Energy ◽  
Ct Scans ◽  
Dual Energy Ct ◽  
Abdominal Ct ◽  
Body Habitus ◽  
Portal Venous Phase ◽  
Dual Source ◽  
Venous Phase

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.

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