ObjectiveTo analyze the processing mechanism underlying the enhanced effect of invigorating spleen and stopping diarrhea of soil-fried Atractylodis Macrocephalae Rhizoma（AMR） by analyzing the changes of microstructure， chemical composition and anti-ulcerative colitis（UC） activity before and after soil stir-frying. MethodsThe microstructure and elemental composition of AMR before and after soil stir-frying were analyzed by scanning electron microscopy-energy dispersive spectroscopy（SEM-EDS）， to investigate the differences in microstructure and the underlying causes. Ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS） coupled with UNIFI 1.9.2 natural product analysis platform were used to analyze and identify the chemical constituents in raw and soil-fried products， and multivariate statistical methods including principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to explore the differences and sources of chemical constituents between them. A dextran sulfate sodium（DSS）-induced UC mouse model was established. The method of disease activity index（DAI） was used to evaluate the severity of intestinal inflammation. Hematoxylin-eosin（HE） staining was used to observe the pathological changes of colon tissue， enzyme-linked immunosorbent assay（ELISA） was used to detect the levels of inflammatory factors， Real-time quantitative polymerase chain reaction（Real-time PCR） and Western blot were used to analyze the expressions of key genes and proteins involved in the intestinal mucosal barrier. The 16S rRNA sequencing was used to evaluate the diversity of intestinal flora， headspace gas chromatography-mass spectrometry（HS-GC-MS） was used to explore the levels of short-chain fatty acids（SCFAs） in feces. Base on the above findings， this paper investigated the effects of raw and soil-fried AMR on the biological， chemical， mechanical and immune barriers of model animals， and the differences in pharmacological effects and underlying mechanisms from the perspective of regulating the intestinal mucosal barrier in UC mice. ResultsSEM observation revealed numerous hearth soil particles on the surface of soil-fried AMR， accompanied by bubble-like bulges. At the same time， there were many cracks and folds on the surface of the hearth soil. EDS analysis revealed that the contents of Si， Al， Mg and Ca in soil-fried AMR were significantly higher than those of raw products， and these elements constituted the primary components of hearth soil. UPLC-Q-TOF-MS combined with database comparison was used to identify the chemical constituents of raw and soil-fried AMR. In positive ion mode， a total of 132 components were identified， primarily comprising three categories of terpenoids， polyphenols and amino acids. In negative ion mode， a total of 40 components were identified， primarily polyphenolic and glycoside compounds. Among them， the contents of sesquiterpenes and polyphenolic acids were changed significantly before and after processing. Soil-fried AMR could reduce the DAI score of UC mice， alleviate the shortening of colon length， reduce the levels of pro-inflammatory factors such as interleukin（IL）-17， IL-18， γ-interferon（IFN-γ） and tumor necrosis factor（TNF）-α in serum， increase the levels of anti-inflammatory factors such as secretory immunoglobulin A（sIgA）， IL-10， IL-4 and transforming growth factor-β（TGF-β） in serum， increase the expressions of key genes and proteins of intestinal mucosal barrier such as tight junction protein-1（ZO-1）， Occludin， Claudin-1 and mucin 2（MUC2） in colonic mucosa， and improve the disorders of intestinal flora diversity and the levels of SCFAs（P<0.05， P<0.01）. The raw and stir-fried products of AMR also exhibited the aforementioned effects， but they were weaker than the soil-fried products. Additionally， the auxiliary material hearth soil also had a certain pharmacodynamic effect. ConclusionSoil-fried AMR can enhance the protective effect on intestinal mucosal barrier in UC mice. These changes or heating-induced alterations in the microscopic structure and chemical composition of AMR may be attributed to the dual effects of adsorption of hearth soil.

ObjectiveTo analyze the processing mechanism underlying the enhanced effect of invigorating spleen and stopping diarrhea of soil-fried Atractylodis Macrocephalae Rhizoma（AMR） by analyzing the changes of microstructure， chemical composition and anti-ulcerative colitis（UC） activity before and after soil stir-frying. MethodsThe microstructure and elemental composition of AMR before and after soil stir-frying were analyzed by scanning electron microscopy-energy dispersive spectroscopy（SEM-EDS）， to investigate the differences in microstructure and the underlying causes. Ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS） coupled with UNIFI 1.9.2 natural product analysis platform were used to analyze and identify the chemical constituents in raw and soil-fried products， and multivariate statistical methods including principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to explore the differences and sources of chemical constituents between them. A dextran sulfate sodium（DSS）-induced UC mouse model was established. The method of disease activity index（DAI） was used to evaluate the severity of intestinal inflammation. Hematoxylin-eosin（HE） staining was used to observe the pathological changes of colon tissue， enzyme-linked immunosorbent assay（ELISA） was used to detect the levels of inflammatory factors， Real-time quantitative polymerase chain reaction（Real-time PCR） and Western blot were used to analyze the expressions of key genes and proteins involved in the intestinal mucosal barrier. The 16S rRNA sequencing was used to evaluate the diversity of intestinal flora， headspace gas chromatography-mass spectrometry（HS-GC-MS） was used to explore the levels of short-chain fatty acids（SCFAs） in feces. Base on the above findings， this paper investigated the effects of raw and soil-fried AMR on the biological， chemical， mechanical and immune barriers of model animals， and the differences in pharmacological effects and underlying mechanisms from the perspective of regulating the intestinal mucosal barrier in UC mice. ResultsSEM observation revealed numerous hearth soil particles on the surface of soil-fried AMR， accompanied by bubble-like bulges. At the same time， there were many cracks and folds on the surface of the hearth soil. EDS analysis revealed that the contents of Si， Al， Mg and Ca in soil-fried AMR were significantly higher than those of raw products， and these elements constituted the primary components of hearth soil. UPLC-Q-TOF-MS combined with database comparison was used to identify the chemical constituents of raw and soil-fried AMR. In positive ion mode， a total of 132 components were identified， primarily comprising three categories of terpenoids， polyphenols and amino acids. In negative ion mode， a total of 40 components were identified， primarily polyphenolic and glycoside compounds. Among them， the contents of sesquiterpenes and polyphenolic acids were changed significantly before and after processing. Soil-fried AMR could reduce the DAI score of UC mice， alleviate the shortening of colon length， reduce the levels of pro-inflammatory factors such as interleukin（IL）-17， IL-18， γ-interferon（IFN-γ） and tumor necrosis factor（TNF）-α in serum， increase the levels of anti-inflammatory factors such as secretory immunoglobulin A（sIgA）， IL-10， IL-4 and transforming growth factor-β（TGF-β） in serum， increase the expressions of key genes and proteins of intestinal mucosal barrier such as tight junction protein-1（ZO-1）， Occludin， Claudin-1 and mucin 2（MUC2） in colonic mucosa， and improve the disorders of intestinal flora diversity and the levels of SCFAs（P<0.05， P<0.01）. The raw and stir-fried products of AMR also exhibited the aforementioned effects， but they were weaker than the soil-fried products. Additionally， the auxiliary material hearth soil also had a certain pharmacodynamic effect. ConclusionSoil-fried AMR can enhance the protective effect on intestinal mucosal barrier in UC mice. These changes or heating-induced alterations in the microscopic structure and chemical composition of AMR may be attributed to the dual effects of adsorption of hearth soil.

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 clinical characteristics of patients with multiple myeloma(MM)complicated by bone lesions and the risk factors associated with bone lesions.Methods:The clinical data of 294 newly diagnosed MM patients in Gansu Provincial Hospital from January 2017 to June 2021 were retrospectively analyzed.The patients were divided into the bone lesion group(154 cases)and the non-bone lesions group(140 cases)based on the presence of absence of bone lesions at diagnosis.The general data and laboratory parameters were compared between the two groups.The risk factors for bone lesions in MM patients were analyzed by logistic regression analysis,and the characteristic(ROC)curves were plotted to assess the predictive value of each risk factor for the occurrence of bone lesions in MM patients.Results:Compared to the non-bone lesion group,the bone lesion group had significantly higher serum calcium levels and significantly greater proportions of patients with Durie-Salmon(DS)stage Ⅲ,and bone pain(all P＜0.05).Logistic regression analysis showed that elevated serum calcium(OR=5.135,95％CI:1.931-13.653,P=0.001),DS stage Ⅲ(OR=1.841,95％CI:1.019-3.328,P=0.043),and bone pain(OR=8.208,95％CI:4.761-14.151,P＜0.001)were independent risk factors for bone lesions in MM patients.ROC curve analysis showed that serum calcium(AUC=0.619,95％CI:0.555-0.683,P＜0.001)and bone pain(AUC=0.743,95％CI:0.692-0.793,P＜0.001)had predictive value for bone lesions in MM patients.Conclusion:MM patients have a high incidence of bone lesions,and active monitoring and management of risk factors may improve treatment outcomes and prognosis.

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.

BACKGROUND:During bone tissue healing,promoting the vascularization of new bone is a common strategy to accelerate the repair of bone tissue.However,the rapid fibrosis process during bone defect repair is often ignored.OBJECTIVE:To design and prepare a core-shell structure bionic scaffold to regulate the process of fibrosis and vascularization in new callus,characterize physical characteristics of the scaffold,and verify the anti-fibrosis and osteogenic properties in vitro and in vivo.METHODS:A core-shell structure bionic scaffold to regulate the process of fibrosis and vascularization in new callus was designed and prepared.The outer shell structure of the scaffold was composed of polycaprolactone electrospun nanofibers loaded with fibroblast activating protein inhibitor;and the inner core structure was composed of gelatin methacrylate hydrogel loaded with deferoxamine.The physical characteristics of electrospun and hydrogel were characterized,and the biocompatibility of the material was verified by live-dead staining and CCK-8 assay.The antifibrotic effect of core-shell structure was analyzed by fibroblast in vitro assay.The osteogenic effect of fibroblast activating protein inhibitor in core-shell structure was analyzed by MC3T3-E1 cells in vitro assay.The vasogenic effect of deferoxamine in core-shell structure was analyzed by human umbilical vein endothelial cells.The effect of bionic core-shell scaffold on bone repair was evaluated by critical bone defect test in rats.RESULTS AND CONCLUSION:(1)The core-shell structure bionic scaffold had good biocompatibility.Hydrophobic polycaprolactone electrospun fibers prepared by electrospinning technology could effectively block the ingrowth of exogenous fibrous tissue on the physical level.The electrospun fiber membrane could effectively release the anti-fibrosis drug fibroblast activating protein inhibitor within 2 weeks,and the released anti-fibrosis drug could inhibit the growth and adhesion of fibroblasts around bone defects,effectively reduced the expression of fibroblast-related proteins,promoted the expression of osteoblast protein in MC3T3-E1 cells,and accelerated its mineralization rate.The deferoxamine in the core-shell structure could promote the migration and vascular formation ability of human umbilical vein endothelial cells,and promoted their strong expression of"H"vascular characteristic protein.(2)In critical bone defect model of SD rats established in the femur,compared with polycaprolactone membrane,the core-shell structure bionic scaffold could effectively repair bone defects.(3)These findings indicate that the core-shell structure bionic scaffold can prevent excessive fibrosis of callus and promote the formation of"H"vessels in the new callus,which can effectively avoid the occurrence of nonunion and accelerate the repair process of critical bone defect.

BACKGROUND:Cell senescence is one of the major risk factors for osteoarthritis,but there is no widely accepted anti-osteoarthritis therapy targeting senescent cells.OBJECTIVE:To develop a feasible treatment strategy targeting senescent cells in osteoarthritis.METHODS:The cationic liposome containing rapamycin,RAPA@Lipo,was prepared by thin film dispersion method.Methylallylated hyaluronic acid hydrogel was synthesized,and RAPA@Lipo was added to the methylallylated hyaluronic acid hydrogel aqueous phase solution.The hydrogel microspheres were prepared by microfluidic equipment.Solid hydrogel microspheres(RAPA@Lipo@MS)were crosslinked under violet light.Primary human chondrocytes were co-cultured with RAPA@Lipo and RAPA@Lipo@MS,respectively.The biocompatibility of the materials was evaluated by CCK-8 assay and live/dead staining.Primary rat chondrocytes were cultured in four groups.Normal control group was cultured for 48 hours.The model group was stimulated with H2O2 for 24 hours to establish senescent cell model.RAPA@Lipo group and RAPA@Lipo@MS group were cultured for 24 hours after establishing senescent cell model with RAPA@Lipo and RAPA@Lipo@MS,respectively.After culture,immunofluorescence was used to observe the expression of p62 and type Ⅱ collagen.RT-PCR was used to detect the mRNA expression of interleukin 6,matrix metalloproteinase 13,type Ⅱ collagen,aggrecan,and ADAMTS-5.RESULTS AND CONCLUSION:(1)The results of CCK-8 assay and live/dead staining showed that RAPA@Lipo and RAPA@Lipo@MS had good biocompatibility.(2)Compared with the normal control group,the protein expression of p62 was increased(P<0.05);the expression of type Ⅱ collagen was decreased(P<0.05),and the mRNA expression levels of interleukin 6,matrix metalloproteinase 13,and ADAMTS-5 were increased(P<0.05);mRNA expression levels of type Ⅱ collagen and aggrecan were decreased(P<0.05)in the model group.Compared with the model group,the expression of p62 protein was decreased(P<0.05);the expression of type Ⅱ collagen was increased(P<0.05),and the mRNA expression levels of interleukin 6,matrix metalloproteinase 13,and ADAMTS-5 were decreased(P<0.05);mRNA expression of type Ⅱ collagen and aggrecan increased(P<0.05)in the RAPA@Lipo@MS group.(3)These findings indicate that RAPA@Lipo@MS can control the quality of cells in vivo by enhancing autophagy,reduce senescent cells in vivo,and locally eliminate senescent cells and senescence-associated secretory phenotype factors in osteoarthritis,thereby slowing the progression of osteoarthritis and creating a cartilage microenvironment that promotes regeneration.

Objective:To investigate the effects of spinal cord injury(SCI)on neuropathic pain(NP)and cognitive dysfunction in mice,as well as the activation of neurons in the anterior cingulate cortex(ACC),in order to provide experimental evidence for the connection between NP and cognitive dysfunction following SCI.Methods:Ten 8-week-old male C57BL/6J mice were used to prepare a model of spinal cord hemisection(SCI).Pain behavior and cognitive function of mice after SCI were assessed using von Frey,thermal stimulation,and Morris water maze behavioral experi-ments.Immunofluorescence staining were used to analyze the expression of c-Fos and GAD67/VGLUT2 positive cells in the anterior cingulate cortex(ACC)of the SCI model mice.Results:Compared with the Sham group,the SCI group of mice showed a significant decrease in mechanical threshold and thermal pain threshold(P＜0.05).The Morris water maze results indicated a significantly prolonged escape latency(P＜0.05)and a significant reduction in the use of search strategies for locating the hidden platform.Immunofluorescence results showed a significant increase in the num-ber of c-Fos positive cells in the ACC(P＜0.05),which were mainly co-labeled with excitatory neuron marker VGLUT2 positive cells.Conclusion:SCI leads to abnormal pain behavior and cognitive dysfunction in mice,and it induces the activation of neurons in the ACC,with a predominant activation of excitatory neurons.This study provides morphological evidence for the involvement of excitatory neurons in the ACC in the comorbidity of NP and cognitive impairment following SCI.

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.