Objective:To assess the viability of reducing radiation dose, contrast media volume, injection flow rate and contrast medium concentration (quadruple low-dose protocol) by utilizing virtual monoenergetic images (VMI) in photon-counting detector CT (PCD-CT) for aortic CT angiography (CTA), while maintaining image quality in comparison to images obtained from energy-integrating detector CT (EID-CT).Methods:From April 2024 to June 2024, a total of 40 participants who underwent aortic CTA on PCD-CT were prospectively enrolled in the experimental group (PCD-CT group), while 40 patients with similar baseline characteristics who had previously undergone aortic CTA using EID-CT were retrospectively selected for the conventional group (EID-CT group). The EID-CT group used a tube voltage of 90 kVp, a contrast media volume of 60 ml of contrast, an injection flow rate of 3 ml/s, and a contrast concentration of 350 mgI/ml; the PCD-CT group used the QuantumPlus mode, with a tube voltage of 140 kVp, a total amount of iodine in the contrast media of 140 mgI/kg, and an injection flow rate=contrast media volume/(delay time+scan time), and a contrast media concentration of 320 mgI/ml. VMIs in PCD-CT group were reconstructed in 5-keV intervals ranging from 45 to 65 keV. The effective radiation dose and contrast injection protocols were recorded and compared between two groups. Objective image quality assessment was performed for each group. CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured at five anatomical locations (ascending aorta, aortic arch, descending aorta, abdominal aorta, and right common iliac artery), and image noise was recorded. Subjective image quality was independently evaluated by two readers using a 5-point Likert scale in a blinded manner. Based on data normality, the one-way ANOVA or Kruskal-Wallis test was used for image quality assessment, with Bonferroni-corrected post-hoc analysis for multiple comparisons.Results:There were no significant differences in the baseline characteristics between two groups (all P0.05). The PCD-CT group demonstrated significantly lower effective radiation dose [(3.88±0.65) mSv vs. (5.97±1.15)mSv], contrast media volume [(29.25±4.56) ml vs. 60 ml], and injection rate [(2.65±0.42) ml/s vs. 3 ml/s] than the EID-CT group, with reductions of 35%, 51%, and 12%, respectively (all P0.001). For objective image quality, except for the ascending aortic CT attenuation, the CT attenuation, SNR, and CNR of other vessels in the 55 keV PCD-CT group were comparable to those in the EID-CT group. Additionally, the difference in image noise between these two groups was not statistically significant ( P0.05). Concerning subjective image quality, at 55 keV, the PCD-CT group had similar image noise scores and vessel attenuation scores (both P0.05) and better visualization of renal artery branching ( P=0.001) compared to the EID-CT group. Conclusion:In comparison to EID-CT, the use of a 55 keV image in PCD-CT for aortic CTA has demonstrated reductions in radiation dose, contrast media volume, injection flow rate and contrast medium concentration, while maintaining image quality.

Objective:To evaluate the feasibility of head and neck vascular imaging using photon-counting detector computed tomography (PCD-CT) combined with a “quadruple lows” protocol—characterized by low contrast media volume, low iodine concentration, low injection rate, and low radiation dose—and to compare the image quality with that obtained by energy-integrating detector CT (EID-CT).Methods:A total of 105 patients with suspected cerebrovascular disease were prospectively enrolled at the First Affiliated Hospital of Zhengzhou University between April and June 2024. Patients were randomly assigned to three groups ( n=35). Group A underwent conventional head and neck CTA using EID-CT. Group B underwent PCD-CT with a protocol involving ultra-low contrast media volume, low iodine concentration, and low injection rate. Group C underwent PCD-CT with the full “quadruple low” protocol. Objective image quality parameters—including CT attenuation, image noise (standard deviation, SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR)—were measured at the ascending aorta, common carotid artery, internal carotid artery, vertebral artery, basilar artery, posterior cerebral artery, and middle cerebral artery. Two radiologists independently rated subjective image quality using a 5-point Likert scale. Differences among groups were analyzed using one-way ANOVA and the Kruskal-Wallis test. Results:Compared to Group A [contrast volume: (42.78±6.64)ml], contrast agent volume was significantly reduced in Groups B and C[ (26.26±4.45) ml and (26.54±3.83)ml, respectively], demonstrating reductions of 39% and 38% (both P<0.01). The iodine concentration was 320 mg/ml in Groups B and C, lower than 350 mg/ml in Group A (8.5%). The injection rate was also reduced in Groups B and C [(3.39±0.61) and (3.55±0.51)ml/s, respectively] compared to Group A [(4.28±0.66) ml/s], with reductions of 21% and 17% (both P<0.01). The effective dose (ED) was similar between Groups A and B [(1.40±0.15) vs. (1.40±0.19)mSv, P>0.05], while Group C demonstrated a significantly lower ED [(0.99±0.09) mSv], with a reduction of 30% compared to Group A and 29% compared to Group B (both P<0.01).In terms of objective image quality, significant differences in image noise (SD) were observed among the three groups at the vertebral artery, internal carotid artery, posterior cerebral artery, and middle cerebral artery (all P<0.05). Groups B and C showed significantly lower SD compared to Group A ( P<0.05), with no significant difference between B and C ( P>0.05). SNR was significantly higher in Groups B and C than in Group A at multiple vascular segments (all P<0.05). CNR differed only at the internal carotid artery, where Groups B and C demonstrated superior performance compared to Group A ( P<0.05).Subjective image quality scores showed no significant difference between Groups A and C ( P>0.05), while Group B had significantly higher scores than both A and C ( P<0.05). All images were deemed diagnostically acceptable. Conclusion:Compared with conventional EID-CT, PCD-CT combined with a “quadruple lows” protocol enables substantial reductions in contrast media and radiation dose while further improving image quality in head and neck CTA.

Objective To observe the feasibility of photon-counting detector(PCD)-CT combined with"four-lows"protocol(low contrast agent concentration,low contrast dose,low contrast agent flow rate,low radiation dose)for coronary CT angiography(CCTA).Methods Totally 106 patients with suspected coronary artery disease were prospectively enrolled and randomized into energy-integrating detector(EID)-CCTA(group A,using conventional scanning protocol,n=52)or PCD-CCTA(group B,using"four-lows"scanning protocol,n=54)groups and underwent relative examinations.The radiation dose,subjective and objective evaluation results of imaging quality were compared between groups.Results The contrast agent dose and flow rate,volume CT dose index,dose length product and effective dose in group B were all lower than those in group A(all P＜0.001).The subjective scores in group B were higher than in group A(5[4,5]vs.4[4,5],Z=-2.310,P=0.021).Compared with group A,CT value,signal-to-noise ratio and contrast-to-noise ratio of aortic root and most of the main branches of coronary arteries increased in group B,while standard deviation of CT value decreased(all P＜0.05).Conclusion PCD-CT combined with"four-lows"protocol could be used for CCTA,which could improve imaging quality and reduce contrast agent usage and radiation dose.

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 assess the viability of reducing radiation dose, contrast media volume, injection flow rate and contrast medium concentration (quadruple low-dose protocol) by utilizing virtual monoenergetic images (VMI) in photon-counting detector CT (PCD-CT) for aortic CT angiography (CTA), while maintaining image quality in comparison to images obtained from energy-integrating detector CT (EID-CT).Methods:From April 2024 to June 2024, a total of 40 participants who underwent aortic CTA on PCD-CT were prospectively enrolled in the experimental group (PCD-CT group), while 40 patients with similar baseline characteristics who had previously undergone aortic CTA using EID-CT were retrospectively selected for the conventional group (EID-CT group). The EID-CT group used a tube voltage of 90 kVp, a contrast media volume of 60 ml of contrast, an injection flow rate of 3 ml/s, and a contrast concentration of 350 mgI/ml; the PCD-CT group used the QuantumPlus mode, with a tube voltage of 140 kVp, a total amount of iodine in the contrast media of 140 mgI/kg, and an injection flow rate=contrast media volume/(delay time+scan time), and a contrast media concentration of 320 mgI/ml. VMIs in PCD-CT group were reconstructed in 5-keV intervals ranging from 45 to 65 keV. The effective radiation dose and contrast injection protocols were recorded and compared between two groups. Objective image quality assessment was performed for each group. CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured at five anatomical locations (ascending aorta, aortic arch, descending aorta, abdominal aorta, and right common iliac artery), and image noise was recorded. Subjective image quality was independently evaluated by two readers using a 5-point Likert scale in a blinded manner. Based on data normality, the one-way ANOVA or Kruskal-Wallis test was used for image quality assessment, with Bonferroni-corrected post-hoc analysis for multiple comparisons.Results:There were no significant differences in the baseline characteristics between two groups (all P0.05). The PCD-CT group demonstrated significantly lower effective radiation dose [(3.88±0.65) mSv vs. (5.97±1.15)mSv], contrast media volume [(29.25±4.56) ml vs. 60 ml], and injection rate [(2.65±0.42) ml/s vs. 3 ml/s] than the EID-CT group, with reductions of 35%, 51%, and 12%, respectively (all P0.001). For objective image quality, except for the ascending aortic CT attenuation, the CT attenuation, SNR, and CNR of other vessels in the 55 keV PCD-CT group were comparable to those in the EID-CT group. Additionally, the difference in image noise between these two groups was not statistically significant ( P0.05). Concerning subjective image quality, at 55 keV, the PCD-CT group had similar image noise scores and vessel attenuation scores (both P0.05) and better visualization of renal artery branching ( P=0.001) compared to the EID-CT group. Conclusion:In comparison to EID-CT, the use of a 55 keV image in PCD-CT for aortic CTA has demonstrated reductions in radiation dose, contrast media volume, injection flow rate and contrast medium concentration, while maintaining image quality.

Objective:To evaluate the feasibility of head and neck vascular imaging using photon-counting detector computed tomography (PCD-CT) combined with a “quadruple lows” protocol—characterized by low contrast media volume, low iodine concentration, low injection rate, and low radiation dose—and to compare the image quality with that obtained by energy-integrating detector CT (EID-CT).Methods:A total of 105 patients with suspected cerebrovascular disease were prospectively enrolled at the First Affiliated Hospital of Zhengzhou University between April and June 2024. Patients were randomly assigned to three groups ( n=35). Group A underwent conventional head and neck CTA using EID-CT. Group B underwent PCD-CT with a protocol involving ultra-low contrast media volume, low iodine concentration, and low injection rate. Group C underwent PCD-CT with the full “quadruple low” protocol. Objective image quality parameters—including CT attenuation, image noise (standard deviation, SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR)—were measured at the ascending aorta, common carotid artery, internal carotid artery, vertebral artery, basilar artery, posterior cerebral artery, and middle cerebral artery. Two radiologists independently rated subjective image quality using a 5-point Likert scale. Differences among groups were analyzed using one-way ANOVA and the Kruskal-Wallis test. Results:Compared to Group A [contrast volume: (42.78±6.64)ml], contrast agent volume was significantly reduced in Groups B and C[ (26.26±4.45) ml and (26.54±3.83)ml, respectively], demonstrating reductions of 39% and 38% (both P<0.01). The iodine concentration was 320 mg/ml in Groups B and C, lower than 350 mg/ml in Group A (8.5%). The injection rate was also reduced in Groups B and C [(3.39±0.61) and (3.55±0.51)ml/s, respectively] compared to Group A [(4.28±0.66) ml/s], with reductions of 21% and 17% (both P<0.01). The effective dose (ED) was similar between Groups A and B [(1.40±0.15) vs. (1.40±0.19)mSv, P>0.05], while Group C demonstrated a significantly lower ED [(0.99±0.09) mSv], with a reduction of 30% compared to Group A and 29% compared to Group B (both P<0.01).In terms of objective image quality, significant differences in image noise (SD) were observed among the three groups at the vertebral artery, internal carotid artery, posterior cerebral artery, and middle cerebral artery (all P<0.05). Groups B and C showed significantly lower SD compared to Group A ( P<0.05), with no significant difference between B and C ( P>0.05). SNR was significantly higher in Groups B and C than in Group A at multiple vascular segments (all P<0.05). CNR differed only at the internal carotid artery, where Groups B and C demonstrated superior performance compared to Group A ( P<0.05).Subjective image quality scores showed no significant difference between Groups A and C ( P>0.05), while Group B had significantly higher scores than both A and C ( P<0.05). All images were deemed diagnostically acceptable. Conclusion:Compared with conventional EID-CT, PCD-CT combined with a “quadruple lows” protocol enables substantial reductions in contrast media and radiation dose while further improving image quality in head and neck CTA.

Objective To observe the feasibility of photon-counting detector(PCD)-CT combined with"four-lows"protocol(low contrast agent concentration,low contrast dose,low contrast agent flow rate,low radiation dose)for coronary CT angiography(CCTA).Methods Totally 106 patients with suspected coronary artery disease were prospectively enrolled and randomized into energy-integrating detector(EID)-CCTA(group A,using conventional scanning protocol,n=52)or PCD-CCTA(group B,using"four-lows"scanning protocol,n=54)groups and underwent relative examinations.The radiation dose,subjective and objective evaluation results of imaging quality were compared between groups.Results The contrast agent dose and flow rate,volume CT dose index,dose length product and effective dose in group B were all lower than those in group A(all P＜0.001).The subjective scores in group B were higher than in group A(5[4,5]vs.4[4,5],Z=-2.310,P=0.021).Compared with group A,CT value,signal-to-noise ratio and contrast-to-noise ratio of aortic root and most of the main branches of coronary arteries increased in group B,while standard deviation of CT value decreased(all P＜0.05).Conclusion PCD-CT combined with"four-lows"protocol could be used for CCTA,which could improve imaging quality and reduce contrast agent usage and radiation dose.

Objective To investigate the effects of interleukin(IL)-34 on the polarization and migration ability of macrophages derived from human peripheral blood monocytes.Methods The CD14+monocytes were isolated from human peripheral blood monocytes by immunomagnetic bead sorting,and the purity of CD14+monocytes was detected by flow cytometry.The CD14+monocytes were divided into M1 type group,IL-34-M1 type group,M2 type group and IL-34-M2 type group.The cells in the M1 type group and IL-34-M1 type group were added granulocyte-macrophage colony stimulating factor(GM-CSF)to induce for 5 days,and half of the fluid was changed,and then the interferon-γ,lipopolysaccharides,IL-6 and GM-CSF were added for another 4-day induction;the cells in the M2 type group and IL-34-M2 type group were added macrophage colony stimulating factor(M-CSF)to induce for 5 days,and half of the fluid was changed,and M-CSF,IL-4,IL-6,and IL-13 were added for another 4-day induction.The cells in IL-34-M1 group and IL-34-M2 group were co-induced with IL-34 at the beginning of induction and on the 5th day of induction.On the 9th day of induction,the proportion of CD14+CD86+cells(M1 type macrophages)and CD14+CD163+cells(M2 type macrophages)in each group was detected by flow cytometry,and the migration ability of cells in the M2 type group and IL-34-M2 type group was detected by the Transwell chamber experiments.Results High purity CD14+monocytes were obtained through magnetic bead sorting,with a CD14 positive rate of(96.77± 2.72)％,which could be used for macrophage induction.The proportion of CD14+CD86+cells in the M1 type group and IL-34-M1 type group was(43.20±7.59)％and(27.87±2.06)％,respectively.The proportion of CD14+CD163+cells in the M2 type group and IL-34-M2 type group was(47.70±4.49)％and(58.95±3.65)％,respectively;the proportion of CD14+CD86+cells in the IL-34-M1 type group was significantly lower than that in the M1 type group(P＜0.05),while the proportion of CD14+CD163+cells in the IL-34-M2 type group was significantly higher than that in the M2 type group(P＜0.05).The number of migrating cells of macrophages in the M2 type group and IL-34-M2 type group was 97.8±9.0 and 205.6±21.9,respectively;the number of migrating cells of macrophages in the IL-34-M2 type group was significantly higher than that in the M2 type group(P＜0.05).Conclusion IL-34 can inhibit the polarization of macrophages derived from human monocytes cells towards M1 type,promote the polarization of macrophages towards M2 type,and enhance the migration ability of M2 type macrophages.

Objective:To explore the incidence, clinical characteristics, imaging features, clinical outcome and prognosis of indeterminate pulmonary nodules (IPN) in patients with osteosarcoma.Methods:A total of 69 patients of osteosarcoma with IPN in lung treated in the Bone tumor Center of Eastern Theater General Hospital from January 2011 to January 2021 were collected retrospectively, there were 47 males and 22 females, with a median age of 19 years old (range 7-60 years old). The clinical characteristics including disease-free interval, the chemotherapy response, with recurrence/non-pulmonary, IPN presence before / during / after chemotherapy and imaging features of IPN including number of IPN, location of IPN, density of IPN, boundary clarity of IPN and outcome. The patients were divided into the metastasis pulmonary nodules group and the benign nodules group according to the final outcome of IPN. Further, χ 2 test was performed for comparison of the clinical and imaging characteristics between the two groups. The survival of patients was counted and the correlation between single factor and survival was compared by Kaplan-Meier test, and multivariate survival analyses were performed using Cox proportional hazards regression models. Results:Sixty-nine cases occurred IPN in 211 patients with osteosarcoma, with an incidence of 32.7%. Of the 69 patients, 45 patients (65.2%) with IPN were diagnosed as metastases, and 24 patients (34.8%) with IPN were diagnosed as benign nodules. Follow-up length ranged from 1 to 124 months, with the median follow up time 43 months. To the end of follow-up, 41 patients (59.4%) remained alive and 28 patients (40.6%) had died. The median survival time was 41.0 (20.0, 65.0) months and the median survival time after diagnosis of IPN was 25.0 (10.0, 43.0) months. There were significant differences in lung nodule density ( P<0.001), boundary ( P=0.002), history of recurrence/extra-pulmonary metastasis ( P=0.023) and chemotherapeutic effect ( P<0.001) between the metastasis pulmonary nodules group and the benign nodules group. Multivariate survival analysis showed that chemotherapeutic effect was an independent factor affecting the overall survival of patients [ HR=0.048, 95% CI (0.01, 0.26)]. Boundary definition [ HR=0.12, 95% CI (0.02, 0.93)] and chemotherapeutic effect [ HR=0.06, 95% CI (0.01, 0.29)] were independent factors influencing survival after diagnosis of IPN. Conclusion:Osteosarcoma patients with IPN have a poor prognosis. The poor effect of chemotherapy is an independent risk factor for the overall survival time of those patients and the survival time after diagnosis of IPN. The boundary definition of IPN is an independent risk factor for the survival time after diagnosis of IPN.