Objective:To investigate the value of quantitative parameters of dual-layer detector spectral CT (DLCT) in preoperative prediction of lymphovascular invasion (LVI) in invasive lung adenocarcinoma.Methods:This study employed a cross-sectional design. The data of 91 patients with primary lung adenocarcinoma confirmed by postoperative pathology who underwent DLCT enhanced scanning in the First Affiliated Hospital of Zhengzhou University from March 2022 to July 2024 were retrospectively collected. The patients were divided into LVI positive group and LVI negative group according to the postoperative pathology. Gender, age, smoking status, and lesion location were recorded,the clinical T-stage and N-stage were evaluated. Spectral base data images were generated based on the spectral reconstruction algorithm. Conventional CT features such as the size and density of the lesions were analyzed. The DLCT quantitative parameters such as 40 keV single-energy CT value (CT 40 keV), iodine density (ID), standardized iodine density (NID), and effective atomic number (Z eff) were measured. The differences of parameters between the two groups were compared using t-test, Mann-Whitney U test, or χ2 test. Multivariate logistic regression analysis was used to identify independent factors for predicting invasive lung adenocarcinoma LVI. The predictive performance of individual parameters and their combinations for LVI in invasive lung adenocarcinoma was evaluated using receiver operating characteristic curve analysis and area under the curve (AUC) measurements. Results:There were significant differences in age, T stage, N stage, maximum diameter, focal density, and arteriovenous stage NID and Z eff between the LVI positive group and the LVI negative group ( P<0.05). Multiple logistic regression analysis showed that age ( OR=0.890, 95% CI 0.821-0.966), N stage( OR=12.721, 95% CI 2.676-60.473) and venous stage Z eff( OR=0.012,95% CI 0-0.668) were independent factors for predicting invasive lung adenocarcinoma LVI ( P<0.05). The combination of age, N stage, and venous-phase Z eff values demonstrated the highest predictive efficacy for LVI in invasive lung adenocarcinoma, with an AUC of 0.916. Conclusions:The quantitative parameters of DLCT are helpful for preoperative prediction of LVI status of invasive lung adenocarcinoma. The Z eff in the venous stage is an independent predictor, the combination of multiple parameters can further improve the diagnostic efficiency.

Objective To explore the predictive value of quantitative parameters of dual-layer detector spectral CT(DLCT)for Ki-67 expression in solid lung adenocarcinoma.Methods The data of 103 patients were retrospectively collected,and the patients were divided into Ki-67 high expression and Ki-67 low expression groups according to Ki-67 proliferation index.The quantitative parame-ters of DLCT were measured and calculated,and the differences in these parameters between the two groups were compared.The parameters with statistically significant differences were assessed for correlation with Ki-67 expression.The efficacy of DLCT param-eters and combined parameters in predicting Ki-67 expression in solid lung adenocarcinoma were evaluated by receiver operating character-istic(ROC)curve and compared by DeLong test.Results Long diameter,short diameter and smoking history were positively corre-lated with the Ki-67 expression in solid lung adenocarcinoma(r>0,P<0.05).Gender and quantitative parameters of DLCT were nega-tively correlated with the Ki-67 expression in solid lung adenocarcinoma(r<0,P<0.05).The combined parameters of convention and spectral CT had the highest prediction efficiency.Conclusion The quantitative parameters of DLCT can be used to evaluate the Ki-67 expres-sion in solid lung adenocarcinoma.

Objective To explore the predictive value of quantitative parameters of dual-layer detector spectral CT(DLCT)for Ki-67 expression in solid lung adenocarcinoma.Methods The data of 103 patients were retrospectively collected,and the patients were divided into Ki-67 high expression and Ki-67 low expression groups according to Ki-67 proliferation index.The quantitative parame-ters of DLCT were measured and calculated,and the differences in these parameters between the two groups were compared.The parameters with statistically significant differences were assessed for correlation with Ki-67 expression.The efficacy of DLCT param-eters and combined parameters in predicting Ki-67 expression in solid lung adenocarcinoma were evaluated by receiver operating character-istic(ROC)curve and compared by DeLong test.Results Long diameter,short diameter and smoking history were positively corre-lated with the Ki-67 expression in solid lung adenocarcinoma(r>0,P<0.05).Gender and quantitative parameters of DLCT were nega-tively correlated with the Ki-67 expression in solid lung adenocarcinoma(r<0,P<0.05).The combined parameters of convention and spectral CT had the highest prediction efficiency.Conclusion The quantitative parameters of DLCT can be used to evaluate the Ki-67 expres-sion in solid lung adenocarcinoma.

Objective To observe the value of deep learning image reconstruction(DLIR)algorithm in brain CT perfusion(CTP)using a protocol of 70 kVp and 40 ml contrast agent dose.Methods Totally 105 patients with suspected acute ischemic stroke(AIS)were prospectively enrolled and randomly divided into 3 groups,who underwent standard dose CTP scanning with 80 kVp and 150 mA combined with reconstruction as adaptive statistic iterative reconstruction V(ASIR-V)at 50％level(CN group,n=35),low dose(LD)scanning with 70 kVp and 100 mA combined with DLIR reconstruction at the highest level(DLIR-H)(LD group,n=35),or ultra-low dose(ULD)scanning with 70 kVp and 70 mA combined with DLIR-H reconstruction(ULD group,n=35).Radiation doses were compared among 3 groups.CT values and standard deviations(SDCT)of ROI of gray matter and white matter in the frontal,parietal and temporal lobes were measured.Signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)between gray and white matter were calculated and compared among groups.Then pseudo-color images of cerebral blood volume(CBV),cerebral blood flow(CBF),mean transit time(MTT)and time to maximum of the tissue residual function(Tmax)were generated.The imaging quality of CTP pseudo-color images was evaluated,and the compatibility of the subjective scores within every kind of CTP pseudo-color images were assessed using Kappa test.Quantitative perfusion parameters were measured and compared among groups.Results Compared with CN group,both LD and ULD groups demonstrated significantly reduced volume CT dose index(CTDIvol),dose-length product(DLP)and effective dose(ED)(all adjusted P＜0.05).In ULD group,SDCT of white matter in frontal,parietal and temporal lobes were higher than those in CN group,and SDCT of white matter in parietal lobe was also higher than that in LD group(all adjusted P＜0.05).No significant difference of SDCT of gray matter was observed among groups(all P＞0.05).SNR of white matter in parietal and temporal lobes in both LD and ULD groups were lower than those in CN group(all P＜0.05),while no significant difference of SNR of white matter in frontal lobe,nor of gray matter in frontal,parietal and temporal lobes was found among groups(all P＞0.05).CNR of gray and white matter in the frontal,parietal and temporal lobes were not significantly different among groups(all P＞0.05).High consistency of inter-observer subjective scores of CBV maps,CBF maps and Tmax maps(Kappa of 0.623,0.644 and 0.638,respectively)were noticed,which of MTT maps had moderate consistency(Kappa=0.560).No significant difference of intra-obsever subjective scores of CTP pseudo-color images was found among groups(all P＞0.05).CBV,CBF,MTT and Tmax values of gray and white matter in frontal,parietal and temporal lobes were not significantly different among groups(all P＞0.05).Conclusion DLIR algorithm applicated in low radiation dose and reduced contrast agent dosage might ensure imaging quality.

Objective To observe the value of deep learning image reconstruction(DLIR)algorithm in brain CT perfusion(CTP)using a protocol of 70 kVp and 40 ml contrast agent dose.Methods Totally 105 patients with suspected acute ischemic stroke(AIS)were prospectively enrolled and randomly divided into 3 groups,who underwent standard dose CTP scanning with 80 kVp and 150 mA combined with reconstruction as adaptive statistic iterative reconstruction V(ASIR-V)at 50％level(CN group,n=35),low dose(LD)scanning with 70 kVp and 100 mA combined with DLIR reconstruction at the highest level(DLIR-H)(LD group,n=35),or ultra-low dose(ULD)scanning with 70 kVp and 70 mA combined with DLIR-H reconstruction(ULD group,n=35).Radiation doses were compared among 3 groups.CT values and standard deviations(SDCT)of ROI of gray matter and white matter in the frontal,parietal and temporal lobes were measured.Signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)between gray and white matter were calculated and compared among groups.Then pseudo-color images of cerebral blood volume(CBV),cerebral blood flow(CBF),mean transit time(MTT)and time to maximum of the tissue residual function(Tmax)were generated.The imaging quality of CTP pseudo-color images was evaluated,and the compatibility of the subjective scores within every kind of CTP pseudo-color images were assessed using Kappa test.Quantitative perfusion parameters were measured and compared among groups.Results Compared with CN group,both LD and ULD groups demonstrated significantly reduced volume CT dose index(CTDIvol),dose-length product(DLP)and effective dose(ED)(all adjusted P＜0.05).In ULD group,SDCT of white matter in frontal,parietal and temporal lobes were higher than those in CN group,and SDCT of white matter in parietal lobe was also higher than that in LD group(all adjusted P＜0.05).No significant difference of SDCT of gray matter was observed among groups(all P＞0.05).SNR of white matter in parietal and temporal lobes in both LD and ULD groups were lower than those in CN group(all P＜0.05),while no significant difference of SNR of white matter in frontal lobe,nor of gray matter in frontal,parietal and temporal lobes was found among groups(all P＞0.05).CNR of gray and white matter in the frontal,parietal and temporal lobes were not significantly different among groups(all P＞0.05).High consistency of inter-observer subjective scores of CBV maps,CBF maps and Tmax maps(Kappa of 0.623,0.644 and 0.638,respectively)were noticed,which of MTT maps had moderate consistency(Kappa=0.560).No significant difference of intra-obsever subjective scores of CTP pseudo-color images was found among groups(all P＞0.05).CBV,CBF,MTT and Tmax values of gray and white matter in frontal,parietal and temporal lobes were not significantly different among groups(all P＞0.05).Conclusion DLIR algorithm applicated in low radiation dose and reduced contrast agent dosage might ensure imaging quality.

Objective:To investigate the value of quantitative parameters of dual-layer detector spectral CT (DLCT) in preoperative prediction of lymphovascular invasion (LVI) in invasive lung adenocarcinoma.Methods:This study employed a cross-sectional design. The data of 91 patients with primary lung adenocarcinoma confirmed by postoperative pathology who underwent DLCT enhanced scanning in the First Affiliated Hospital of Zhengzhou University from March 2022 to July 2024 were retrospectively collected. The patients were divided into LVI positive group and LVI negative group according to the postoperative pathology. Gender, age, smoking status, and lesion location were recorded,the clinical T-stage and N-stage were evaluated. Spectral base data images were generated based on the spectral reconstruction algorithm. Conventional CT features such as the size and density of the lesions were analyzed. The DLCT quantitative parameters such as 40 keV single-energy CT value (CT 40 keV), iodine density (ID), standardized iodine density (NID), and effective atomic number (Z eff) were measured. The differences of parameters between the two groups were compared using t-test, Mann-Whitney U test, or χ2 test. Multivariate logistic regression analysis was used to identify independent factors for predicting invasive lung adenocarcinoma LVI. The predictive performance of individual parameters and their combinations for LVI in invasive lung adenocarcinoma was evaluated using receiver operating characteristic curve analysis and area under the curve (AUC) measurements. Results:There were significant differences in age, T stage, N stage, maximum diameter, focal density, and arteriovenous stage NID and Z eff between the LVI positive group and the LVI negative group ( P<0.05). Multiple logistic regression analysis showed that age ( OR=0.890, 95% CI 0.821-0.966), N stage( OR=12.721, 95% CI 2.676-60.473) and venous stage Z eff( OR=0.012,95% CI 0-0.668) were independent factors for predicting invasive lung adenocarcinoma LVI ( P<0.05). The combination of age, N stage, and venous-phase Z eff values demonstrated the highest predictive efficacy for LVI in invasive lung adenocarcinoma, with an AUC of 0.916. Conclusions:The quantitative parameters of DLCT are helpful for preoperative prediction of LVI status of invasive lung adenocarcinoma. The Z eff in the venous stage is an independent predictor, the combination of multiple parameters can further improve the diagnostic efficiency.

Objective:To investigate the value of CT quantitative parameters of tumor and spleen in predicting the clinical stage of gastric cancer (Ⅰ/Ⅱ stage and Ⅲ/Ⅳ stage).Methods:This study was a case-control study. The data of 145 patients with gastric cancer confirmed by pathology in the First Affiliated Hospital of Zhengzhou University from February 2019 to June 2021 were retrospectively collected, including 70 cases of Ⅰ/Ⅱ stage and 75 cases of Ⅲ/Ⅳ stage. On the baseline CT images, the tumor related parameters, including tumor thickness, length of tumor, CT attenuation of tumor unenhanced phase, CT attenuation of tumor arterial phase, CT attenuation of tumor venous phase were measured. The spleen related parameters, including splenic thickness, CT attenuation of splenic unenhanced phase, CT attenuation of splenic arterial phase, CT attenuation of splenic venous phase, and standard deviation of CT attenuation (CTsd) in splenic unenhanced phase were also measured. The independent sample t test or Mann-Whitney U test was used to compare the parameters between the Ⅰ/Ⅱ stage and Ⅲ/Ⅳ stage patients. The multi-factor logistic regression analysis was used to find the independent predictors of gastric cancer clinical stage, and establish the combined parameters. The efficiency to the diagnosis of gastric cancer stage of single and combined parameters was evaluated using the operating characteristic curve, and the DeLong test was used to compare the differences of area under the curve (AUC). Results:There were significant differences in tumor thickness, length of tumor, CT attenuation of tumor venous phase, CT attenuation of splenic unenhanced phase, CT attenuation of splenic venous phase, CTsd in splenic unenhanced phase between the Ⅰ/Ⅱ stage and Ⅲ/Ⅳ stage of gastric cancer ( P<0.05). Multivariate analysis showed that tumor thickness ( OR=1.073, 95% CI 1.026-1.123, P=0.002), CT attenuation of splenic venous phase ( OR=1.040, 95% CI 1.011-1.070, P=0.006) and CTsd in splenic unenhanced phase ( OR=1.625, 95% CI 1.330-1.987, P<0.001) were independent risk factors for the clinical stage of gastric cancer and the combined parameters were established. The AUC values of tumor thickness, CT attenuation of splenic venous phase, CTsd in splenic unenhanced phase and combined parameters were 0.655, 0.614, 0.749 and 0.806, respectively. The AUC of combined parameters was higher than those of tumor thickness and CT attenuation of splenic venous phase, and the differences were statistically significant ( Z=3.37, 3.82, both P<0.001). Conclusion:Tumor thickness, CT attenuation of splenic venous phase and CTsd in splenic unenhanced phase are independent risk factors for the clinical stage of gastric cancer, and combined parameters can improve the diagnostic efficiency.

Objective:To compare image quality and diagnostic parameters of whole-brain CT perfusion scans under different scanning conditions and assess the utility of deep learning image reconstruction algorithm (DLIR) in reducing tube current during low-dose scans.Methods:Method A total of 105 patients with suspected acute ischemic stroke (AIS) were prospectively enrolled in the First Affiliated Hospital of Zhengzhou University from March, 2022 to March, 203 and their baseline information was recorded. All patients underwent head non-contrast CT and CT perfusion (CTP) examinations. CTP scanning was performed at 80 kV in two groups with the tube current of 150 mA (regular dose) and 100 mA (low dose), respectively. The CTP images of 150 mA group were reconstructed using filtered back-projection algorithm as well as adaptive statistical iterative reconstruction-V (ASIR-V) at 40% and 80% strength levels, which were denoted as groups A-C. The CTP images of 100 mA group were reconstructed using ASIR-V80%, DLIR-M, and DLIR-H, which were denoted as groups D-F. Clinical baseline characteristics and radiation doses were compared between the two groups under different scanning conditions. Furthermore, we assessed the subjective and objective image quality, conventional perfusion parameters, and abnormal perfusion parameters of AIS patients across the six groups of reconstructed CTP images.Results:Under the scanning conditions of 150 mA and 100 mA, 47 and 48 patients were diagnosed with AIS, respectively. There were no significant differences in the baseline characteristics between the two groups. However, there was a significant difference in the mean effective radiation dose (5.71 mSv vs. 3.80 mSv, t = 2 768.30, P < 0.001). The standard deviation (SD) of noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of gray matter (GM) and white matter (WM) were significantly different among the six groups of reconstructed images ( F = 40.58-212.13, P < 0.001). In GM, the SD values in groups C, D, and F were lower than those in other groups ( P < 0.05), and the SNR values in groups C and F were higher than those in other groups ( P < 0.05). In WM, the SD and SNR values in groups C and F were significantly different from those in other groups ( P < 0.05). Additionally, CNR values in groups C and F were higher than those in other groups ( P < 0.05). There was no significant difference in subjective scores among groups B, C, and F ( P > 0.05). Regarding perfusion parameters in the brain GM, groups D and E had lower cerebral blood volume (CBV) values compared to groups A to C ( P < 0.05), and group F had lower CBV values than group B ( P < 0.05). In the brain WM, group D had consistently lower mean transit time (MTT) values compared to the other groups ( P < 0.05). Notably, there were no significant differences in AIS lesion detection rates and relevant diagnostic parameters across the six image groups. Conclusions:Low-tube current CTP scan combined with the DLIR-H algorithm can enhance image quality without affecting perfusion parameters such as CBV and MTT, while reducing radiation dose by 30%. This algorithm can be routinely applied in brain CTP examinations.

Objective:To explore the clinical value of quantitative parameters on spectral CT in predicting the invasiveness of lung adenocarcinoma manifesting as ground-glass nodules (GGN).Methods:The clinical and imaging data of 129 patients with pathologically confirmed lung adenocarcinoma who were surgically resected in the First Affiliated Hospital of Zhengzhou University from March to October 2022 were retrospectively analyzed, including 45 males and 84 females, aged from 33 to 81. According to the pathological results, they were divided into the minimally invasive adenocarcinoma (MIA) group ( n=64) and the invasive adenocarcinoma (IAC) group ( n=65). All patients underwent enhanced spectral CT within two weeks before surgery. The iodine density map, Z-Effective (Z eff) map, and electron density (ED) map were reconstructed on the post-processing workstation, and the spectral parameters, including normalized iodine concentration (NIC), arterial enhancement fraction (AEF), Z eff, and ED were measured and calculated. Conventional CT features were analyzed, including maximum diameter, CT value, nodule types, margin, lobulation sign, spiculation sign, bubble sign, pleural retraction sign, abnormal vascular sign, and air bronchial sign. The clinical features, conventional CT characteristics and spectral CT parameters of two groups were compared using the independent sample t test, the Mann-Whitney U test, and the χ 2 test. Multivariate logistic regression analysis was used to evaluate the independent risk factors of lung adenocarcinoma invasiveness, and the model was constructed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the performance of parameters and models in predicting the invasiveness of lung adenocarcinoma. Results:There were significant differences between the MIA group and IAC group in maximum diameter, CT value, nodule type, margin, spiculation sign, pleural retraction sign, air bronchial sign, venous phase NIC, AEF, venous phase Z eff, arterial phase ED, venous phase ED ( P<0.05). Multivariate logistic regression analysis showed that the maximum diameter (OR=1.183, 95%CI 1.062-1.318), CT value (OR=1.004, 95%CI 1.001-1.007), venous phase NIC (OR=1.185, 95%CI 1.083-1.298), AEF(OR=0.975, 95%CI 0.957-0.994), venous phase Z eff (OR=0.031, 95%CI 0.005-0.196) were independent influence factors for the invasiveness of lung adenocarcinoma. The conventional CT model was established with the maximum diameter and CT value, and the spectral CT model was established with venous phase NIC, AEF, and venous phase Z eff. The combined model was established with all the parameters above. Areas under the ROC curve of the conventional CT model, the spectral CT model, and the combined model for predicting the invasiveness of lung adenocarcinoma were 0.828, 0.854, and 0.902, respectively. Conclusion:The quantitative parameters of double-layer detector spectral CT can be used as an indicator to predict the invasiveness of lung adenocarcinoma manifesting as GGN, and AEF has the highest diagnostic efficacy. Spectral CT combined with conventional CT features can further improve the diagnostic efficiency.

Objective:To investigate the application value of spectral computed tomo-graphy (CT) multi-parameter imaging in predicting gastric cancer lymph node metastasis.Methods:The retrospective case-control study was conducted. The clinicopathological data of 86 patients with gastric cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2014 to June 2017 were collected. There were 53 males and 33 females, aged from 22 to 87 years, with a median age of 53 years. All patients received abdominal plain scan and arterial and venous phase contrast spectral scan. Images of plain scan, 70 keV monochromatic and iodine-based images in arterial and venous phase were analyzed on post-processing working station. Observation indicators: (1) gastric cancer lymph node metastasis; (2) analysis of influencing factors for lymph node metastasis in gastric cancer; (3) introduction of special cases. Count data were described as absolute numbers. Univariate analysis was performed using the chi-square test or rank sum test. Multivariate analysis was conducted using the Logistic regression model.Results:(1) Gastric cancer lymph node metastasis: of the 86 patients, 64 cases had lymph nodes metastasis and 22 had no lymph nodes metastasis. (2) Analysis of influencing factors for lymph node metastasis in gastric cancer: results of univariate analysis showed that tumor growth pattern, tumor diameter, infiltration of peritumor fat, CT value in arterial phase, CT value in venous phase, iodine value in venous phase were related factors affecting lymph nodes metastasis in gastric cancer ( χ2=6.753, Z=-3.180, χ2=7.649, Z=-2.051, -2.971, -2.547, P<0.05). Results of multivariate analysis showed that infiltration of peritumor fat and the iodine value in venous phase were greater than 12(100 μg/cm 3) and not greater than 16(100 μg/cm 3), or greater than 16(100 μg/cm 3) were independent risk factors affecting lymph nodes metastasis in gastric cancer ( odds ratio=13.154, 3.761, 7.583, 95% confidence interval as 2.597-66.620, 1.893-8.572, 4.769-16.692, P<0.05). (3) Introduction of special cases: case 1 was male, aged 46 years. Results of preoperative spectral CT enhanced scan showed gastric antrum space occupying lesion combined with enlarged lymph nodes. During enhancement arterial phase, spectral CT 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall thickening with mild to moderate enhancement, clear fat space in serosa and enlarged lymph nodes in lesser curvature. The spectral CT 70 keV monochromatic images and corresponding iodine-based images below pylorus level in the transverse view showed subpyloric enlarged lymph nodes. During enhancement venous phase, the 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed layered enhancement of gastric antrum lesions and mucosal enhancement, with a high iodine value. The patient was diagnosed as gastric antrum cancer with lymph node metastasis, no serosal or peritumoral fat invasion. Results of postoperative pathological examination showed moderately differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis. Case 2 was male, aged 53 years. Results of preoperative spectral CT enhanced scan showed gastric cancer of lesser curvature combined with enlarged lymph nodes. During enhancement arterial phase, 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall heterogeneous thickening of lesser curvature, with moderate enhancement, obscure peritumor fat space, unclear serosa, and multiple enlarged lymph nodes in lesser curvature. During enhancement venous phase, 70 keV monochromatic images in the transverse view showed unclear boundary between lesions and enlarged lymph nodes in lesser curvature, obscure peritumor fat. During enhancement arterial phase, 70 keV monochromatic images of celiac trunk layer in the transverse view showed parasplenic artery lymph nodes, with circular enhancement and no enhancement in central necrotic elements. The patient was diagnosed as gastric cancer of lesser curvature with lymph node metastasis, serosal and peritumor fat invasion. Results of postoperative pathological examination showed poorly differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis. Conclusion:The infiltration of peritumor fat and iodine value in venous phase are independent factors affecting gastric cancer lymph node metastasis.