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Purpose: To investigate whether vorticity could predict functional plaque progression better than high-risk plaque (HRP) and lesion length (LL) in individuals with type 2 diabetes mellitus. Materials and Methods: This single-center prospective study included 61 participants (mean age, 61 years ± 9 [SD]; 43 male participants) who underwent serial coronary CT angiography at 2 years, with 20%-70% stenosis at initial CT between October 2015 and March 2020. The number of the following HRP characteristics was recorded: low attenuation, positive remodeling, spotty calcification, and napkin-ring sign. Vorticity was calculated using a mesh-free simulation. A decrease in CT fractional flow reserve larger than 0.05 indicated functional progression. Models using HRP and LL and vorticity were compared using receiver operating characteristic curve analysis. Results: Of the 94 vessels evaluated, 25 vessels (27%) showed functional progression. Vessels with functional progression showed higher vorticity at distal stenosis (984 sec-1; IQR: 730-1253 vs 443 sec-1; IQR: 295-602; P < .001) than vessels without progression. The area under the receiver operating characteristic curve of vorticity (0.91; 95% CI: 0.84, 0.97) was higher than that of HRP and LL (0.69; 95% CI: 0.56, 0.82; P < .01). Diagnostic accuracy of vorticity (85%; 80 of 94 vessels; 95% CI: 76, 92) was higher than that of HRP and LL (72%; 68 of 94 vessels; 95% CI: 62, 81; P = .004). Conclusion: In participants with type 2 diabetes mellitus, vorticity at distal stenosis was a better predictor of functional plaque progression than HRP and LL.Keywords: Coronary Artery, Vorticity, Functional Plaque Progression, Type 2 Diabetes, Vasculature, CT Angiography, Computational Fluid Dynamics, Fractional Flow Reserve Supplemental material is available for this article. © RSNA, 2023.
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RATIONALE AND OBJECTIVES: Deep-learning-based super-resolution image reconstruction (DLSRR) is a novel image reconstruction technique that is expected to contribute to improvement in spatial resolution as well as noise reduction through learning from high-resolution computed tomography (CT). This study aims to evaluate image quality obtained with DLSRR and assess its clinical potential. MATERIALS AND METHODS: CT images of a Mercury CT 4.0 phantom were obtained using a 320-row multi-detector scanner at tube currents of 100, 200, and 300 mA. Image data were reconstructed by filtered back projection (FBP), hybrid iterative reconstruction (HIR), model-based iterative reconstruction (MBIR), deep-learning-based image reconstruction (DLR), and DLSRR at image reconstruction strength levels of mild, standard, and strong. Noise power spectrum (NPS), task transfer function (TTF), and detectability index were calculated. RESULTS: The magnitude of the noise-reducing effect in comparison with FBP was in the order MBIR
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Background: We aimed to investigate the diagnostic value of energy loss (EL) and baseline CT fractional flow reserve (CT-FFR) computed using computational fluid dynamics to predict functional progression of coronary stenosis in patients with type 2 diabetes mellitus. Methods: This single-center prospective study included 61 patients with type 2 diabetes mellitus (mean age, 61 years ±9 [SD]; 43 men) showing 20-70 % stenosis who underwent serial coronary CT performed at 2-year interval between October 2015 and March 2020. A mesh-free simulation was performed to calculate the CT-FFR and EL. Functional progression was defined as ≥ 0.05 decrease in CT-FFR on the second coronary CT. Models using baseline CT-FFR and EL were compared by analyzing the receiver operating characteristic (ROC) curve. Results: Of the 94 vessels evaluated, 25 vessels (27 %) showed functional progression. EL at distal stenosis (ELdis) of vessels with functional progression was higher than that of vessels without functional progression (27.6 W/m3 [interquartile range (IQR): 15.0, 53.0] vs. 5.7 W/m3 [IQR: 2.3, 10.1], p < 0.001). Multivariable analysis showed that ELdis (per unit Ln(EL); odds ratio, 11.8; 95 % CI: 4.0-34.9; p < 0.001) remained as a predictor of functional progression after adjustment for diameter stenosis and baseline CT-FFR. The area under the ROC curve using ELdis (0.89; 95 % CI: 0.82-0.96) was higher than that using baseline CT-FFR (0.71; 95 % CI: 0.59-0.83; p < 0.001). Conclusion: When ELdis and baseline CT-FFR were considered, ELdis was a better predictor of functional progression of coronary stenosis.
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Purpose: To investigate whether coronary flow kinetic energy has incremental value over simulated fractional flow reserve (sFFR) in diagnosing hemodynamically significant stenosis assessed with coronary CT angiography and invasive fractional flow reserve (FFR). Materials and Methods: This single-center retrospective study included 113 patients (mean age, 68 years ± 9 [SD]; 80 men) who underwent coronary CT angiography showing intermediate stenosis (30%-70% stenosis) and subsequent invasive FFR between December 2015 and March 2020. Kinetic energy was calculated using proximal coronary diameter and myocardial mass of the stenotic region. A mesh-free simulation was performed to calculate the sFFR. Invasive FFR of 0.80 or less indicated hemodynamically significant stenosis. Models using diameter stenosis, kinetic energy, and sFFR were compared by analyzing the receiver operating characteristic curve. Results: Of the 144 vessels evaluated, 53 vessels (37%) had hemodynamically significant stenosis. Kinetic energy of vessels with significant stenosis was higher than that of vessels with nonsignificant stenosis (79 mJ/kg [IQR, 58-104 mJ/kg] vs 36 mJ/kg [IQR, 23-59 mJ/kg]; P < .001). Multivariable analysis including diameter stenosis and sFFR showed that kinetic energy (per 20 mJ/kg; odds ratio, 1.92; 95% CI: 1.37, 2.95; P < .001) was a predictor of hemodynamically significant stenosis. Adding kinetic energy to diameter stenosis and sFFR improved the area under the receiver operating characteristic curve from 0.89 (95% CI: 0.84, 0.95) to 0.93 (95% CI: 0.89, 0.97) (P = .04). Conclusion: Kinetic energy had incremental value over sFFR in detecting hemodynamically significant stenosis assessed with invasive FFR.Keywords: Coronary CT Angiography, Coronary Arteries, Fractional Flow Reserve, Kinetic Energy, Cardiac Supplemental material is available for this article © RSNA, 2022.
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BACKGROUND Computed tomographic colonography (CTC) is useful for patients for whom colonoscopy may be difficult to perform and is widely employed to examine the vasculature prior to colorectal cancer surgery. Computed tomographic angiography (CTA) was shown to be beneficial intraoperatively to manipulate blood vessels and prevent vascular injury. Three-dimensional (3D)-CTA combined with CTC (3D-CTA with CTC) is useful for preoperative evaluations of the anatomy of mesenteric vessels, colon, and lymph nodes. We observed that when the intestine was dilated with carbon dioxide (CO2), the arteriovenous delineation was often more pronounced than without CO2. To clarify the effects of gas injection with and without CO2 on hemodynamics and vascular passage, we compared the effect of contrast for blood vessels. MATERIAL AND METHODS Thirty patients with resectable colorectal cancer who underwent a preoperative CT examination at our institution from January to October 2019 were study participants. Of these, 15 underwent 3D-CTA and 15 had 3D-CTA with CTC. Three board-certified radiologists independently and blindly evaluated 18 blood vessels. CT values for each blood vessel were measured on each image. RESULTS CT values for 3D-CTA with CTC were significantly higher with CO2 than without CO2. The quality of 3D-CTA with CTC images for visualization of blood vessels was also significantly greater than that of 3D-CTA, especially those of arterial and intramesenteric venous systems. CONCLUSIONS Based on the higher image quality and CT values obtained by 3D-CTA with CTC for vessels, compared with by 3D-CTA imaging, 3D-CTA with CTC imaging might be useful in evaluating colorectal cancers.