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OBJECTIVE To evaluate the ability of quantitative MRI parameters for predicting dysthyroid optic neuropathy (DON). METHODS We retrospectively collected and analyzed the clinical features and 3.0 T MRI data of 59 patients with Graves orbitopathy (GO), with (n = 26) and without DON (n = 33). We compared MRI quantitative parameters, including the modified muscle index (mMI), proptosis, volume of intra-orbital fat, mean apparent diffusion coefficient value, and T2 value of the optic nerve among patients with and without DON. A logistic regression analysis was performed to identify the risk factors associated with DON. Moreover, we performed a receiver operating characteristic curve analysis and decision curve analysis to evaluate the diagnostic performance of the identified parameters for DON. RESULTS We studied 118 orbits (43 and 75 with and without DON, respectively). The mMI and mean T2 value of the optic nerve were significantly greater in orbits with DON (p

Background This study aimed to assess the clinical usefulness of 13N-ammonia and 11C- Methionine (MET) positron emission tomography (PET)/ computed tomography (CT) in the differentiation of residual/recurrent pituitary adenoma (RPA) from the pituitary gland remnant (PGR) after trans-sphenoidal adenomectomy. Methods Between June 2012 and December 2019, a total of 19 patients with a history of trans-sphenoidal adenomectomy before PET/CT scans and histological confirmation of RPA after additional surgery in our hospital were enrolled in this study. Images were interpreted by visual evaluation and semi-quantitative analysis. In semi-quantitative analysis, the maximum standard uptake value (SUVmax) of the target and gray matter was measured and the target uptake/gray matter uptake (T/G) ratio was calculated. Results The T/G ratios of 13N-ammonia were significantly higher in PGR than RPA (1.58 ± 0.69 vs 0.63 ± 1.37, P

Background To evaluate the effect of the single energy metal artifact reduction (SEMAR) algorithm with a multidetector CT (MDCT) for knee tumor prostheses. Methods First, a phantom of knee tumor prosthesis underwent a MDCT scan. The raw data was reconstructed by iterative reconstruction (IR) alone and IR plus SEMAR. The mean value of the CT number and the image noise were measured around the prosthesis at the stem level and articular level. Second, 95 consecutive patients with knee tumor prostheses underwent MDCT scans. The raw data were also reconstructed by the two methods. Periprosthetic structures were selected at the similar two levels. Four radiologists visually graded the image quality on a scale from 0 to 5. Additionally, the readers also assessed the presence of prosthetic complication and tumor recurrence on a same scale. Results In the phantom, when the SEMAR was used, the CT numbers were closer to normal value and the noise of images using soft and sharper kernel were respectively reduced by up to 77.1% and 43.4% at the stem level, and by up to 82.2% and 64.5% at the articular level. The subjective scores increased 1 ~ 3 points and 1 ~ 4 points at the two levels, respectively. Prosthetic complications and tumor recurrence were diagnosed in 66 patients. And the SEMAR increased the diagnostic confidence of prosthetic complications and tumor recurrence (4 ~ 5 vs. 1 ~ 1.5). Conclusions The SEMAR algorithm can significantly reduce the metal artifacts and increase diagnostic confidence of prosthetic complications and tumor recurrence in patients with knee tumor prostheses.

Background This study aimed to assess the clinical usefulness of 13N-ammonia and 11C- Methionine (MET) positron emission tomography (PET)/ computed tomography (CT) in the differentiation of residual/recurrent pituitary adenoma (RPA) from the pituitary gland remnant (PGR) after trans-sphenoidal adenomectomy. Methods Between June 2012 and December 2019, a total of 19 patients with a history of trans-sphenoidal adenomectomy before PET/CT scans and histological confirmation of RPA after additional surgery in our hospital were enrolled in this study. Images were interpreted by visual evaluation and semi-quantitative analysis. In semi-quantitative analysis, the maximum standard uptake value (SUVmax) of the target and gray matter was measured and the target uptake/gray matter uptake (T/G) ratio was calculated. Results The T/G ratios of 13N-ammonia were significantly higher in PGR than RPA (1.58 ± 0.69 vs 0.63 ± 1.37, P 11C-MET were obviously lower in PGR than RPA (0.78 ± 0.35 vs 2.17 ± 0.54, P Conclusions The combination of 13N-ammonia and 11C-MET PET/CT is valuable in the differentiation of RPA from PGR after trans-sphenoidal adenomectomy.

Background: To evaluate the effectiveness of the single energy metal artifact reduction (SEMAR) algorithm with a second-generation 320-row multi-detector computed tomography (MDCT) on complications and tumor recurrence detection in patients with hip tumor prostheses.Methods: From February 2016 to June 2019, 31consecutive patients with tumor prostheses of the hip joint underwent CT scans. Lesions were confirmed by histology or clinical and imaging follow-up. Images were reconstructed using 2 methods: iterative (IR) algorithm alone and SEMAR algorithm (IR+ SEMAR). Two radiologists graded the image quality visually by a 6-point (from 0 to 5) ordinal scale. Standard deviations (SD) of CT attenuation value defined as the artifact index (AI) were compared between the two reconstructed methods. Paired sample t-test was adopted to compare the AI values on IR and SEMAR images. Wilcoxon matched-pairs signed rank test was performed to compare the visual scores on IR and SEMAR images. A p- value less than 0.05 was considered statistically significant. Results: The artifacts of the SEMAR images were reduced compared to the Non-SEMAR images (113.94 ±128.54 vs 35.98 ± 53.75HU，t=2.867, P < 0.05). 20 and 16 more lesions were detected by observer 1 and observer 2 with SEMAR algorithm respectively. The mean scores of lesions without SEMAR were 1.39 ± 1.45 (observer 1) and 1.55± 1.34 (observer 2); with SEMAR, the scores were significantly higher, 4.42±0.56 (z=-4.752, p < 0.001) and 4.54± 0.72 (z=-4.837, p < 0.001) respectively. Conclusion: The SEMAR algorithm can effectively reduce metal artifacts in patients with hip tumor prostheses and increase the diagnostic accuracy of prosthetic complications and tumor recurrence.

Modern lean burn combustors are developed to meet environmental requirements of low NOx emissions. Comparing with the rich quench lean combustor, lean burn combustor can produce aggressive swirl fields, higher turbulence intensities and different hot streak patterns at the combustor and turbine interface. The flow structures and heat transfer characteristics of high pressure turbine, especially the nozzle guide vanes (NGVs), are significantly affected by the flow patterns from the upstream combustor. In this paper, unsteady integrated calculations are performed for the full geometry contained two NGVs and a non-reacting swirl combustor. The results of three cases of the full geometry, including positive swirler aligned with passage (Case PSW1), positive swirler aligned with leading edge (Case PSW2) and negative swirler aligned with passage (Case NSW), are compared with a baseline case of only NGV simulations with uniform condition (Case UNF). The results indicate that the core of the swirl migrates near the right NGV pressure side in Case PSW1, and near the left NGV suction side in Cases PSW2 and NSW. Higher intensity of the horse shoe vortices and passage vortices is generated in the three non-uniform cases. Hot streak is closer to the hub in Case NSW than Cases PSW1 and PSW2 at NGV exit. Adiabatic wall temperature distributions are influenced by the hot streak and cold fluid migrations. Nusselt number distributions are influenced by the boundary layer accumulation on the NGV surfaces, and by the secondary flow variations on the endwalls. The flow structure and Nusselt number show the similar distribution patterns in Cases PSW1 and PSW2, especially near the endwalls. While, the Nusselt number and the adiabatic wall temperature are obviously changed by the swirl orientation.

Background Differentiation of suprasellar meningiomas (SSMs) from non-functioning pituitary macroadenomas (NFPMAs) is useful for clinical management. We investigated the utility of 13N-ammonia combined with 18F-FDG positron emission tomography (PET)/computed tomography (CT) in distinguishing SSMs from NFPMAs retrospectively. Methods Fourteen NFPMA patients and eleven SSM patients with histopathologic diagnosis were included in this study. Every patient underwent both 18F-FDG and 13N-ammonia PET/CT scans. The tumor to gray matter (T/G) ratios were calculated for the evaluation of tumor uptake. Results The uptake of 18F-FDG was higher in NFPMAs than SSMs, whereas the uptake of 13N-ammonia was obviously lower in NFPMAs than SSMs. The differences of 18F-FDG and 13N-ammonia uptake between the two groups were significant respectively (0.92[0.46] vs 0.59[0.29], P 18F-FDG; 1.58 ± 0.56 vs 2.80 ± 1.45, P 13N-ammonia). Tumor classification demonstrated a high overall accuracy of 96.0% for differential diagnosis. When the two traces were combined, only 1 SSM was misclassified into the NFPMA group. Conclusion SSMs and NFPMAs have different metabolic characteristics on 18F-FDG and 13N-ammonia PET images. The combination of these two tracers can effectively distinguish SSMs from NFPMAs.

Objective: Differentiation of suprasellar meningiomas (SSMs) from non-functioning pituitary macroadenomas (NFPMAs) is beneficial for clinical management. We investigated the utility of 13 N-ammonia combined with 18 F-FDG positron emission tomography (PET)/computed tomography (CT) in distinguishing SSMs from NFPMAs in this study. Patients and Methods: Fourteen patients with histopathologic diagnosis of NFPMAs and eleven patients with SSMs were included in this study. Every patient underwent both 18 F-FDG and 13 N-ammonia PET/CT scans. The tumor to gray matter (T/G) ratios were calculated for the evaluation of tumor uptake. Results: The uptake of 18 F-FDG was higher in NFPMAs than SSMs whereas the concentration of 13 N- ammonia was lower in NFPMAs than SSMs. There were significant differences of 18 F-FDG and 13 N-ammonia uptake between the two groups (0.92[0.46] vs 0.59[0.29], P