Objective To investigate the application value of spectral computed tomography venography(CTV)in the display and staging of deep venous thrombosis(DVT)in the lower extremity.Methods Eighty-two patients with CTV were selected and ran-domly divided into group A(42 patients)and group B(40 patients).Group A:tube voltage 120 kVp.Group B:gemstone spectral ima-ging(GSI)mode,reconstruction of 50 keV and iodine(water)maps.The CT and standard deviation(SD)values of the veins were measured,signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated in 120 kVp images of group A and in 50 keV images of group B.Two observers scored the image quality of the 2 groups subjectively,and Kappa test was used to examine the con-sistency.Based on the duration from the occurrence of clinical symptoms,the DVTs were classified.The CT values and iodine con-centration(IC)of DVT were measured in the 120 kVp images of group A and in the iodine(water)maps of group B,respectively.The receiver operating characteristic(ROC)curve was drawn to compare the effectiveness of CT values and IC in diagnosing DVT staging.Results CT values,SNR,and CNR of veins in group B were higher than those in group A(P<0.05).The subjective scores of the two groups were consistent(Kappa=0.926-0.955,P<0.05).The score for the display of veins and thrombus clarity in group B was 5(4,5),which was better than the score of 4(3,4)in group A(P<0.05).The efficiency of IC in diagnosing DVT staging[area under the curve(AUC)=0.973]was better than that of CT values(AUC=0.891).Conclusion The spectral CTV can improve the contrast of lower extremity deep veins and the clarity of thrombus,and can provide more objective indicators for the diagnosis of thrombus staging,which is conducive to accurate clinical diagnosis and treatment.

Objective To explore the application value of deep learning image reconstruction(DLIR)algorithm in low-dose deep inferior epigastric artery(DIEA)computed tomography angiography(CTA).Methods A total of 59 patients undergoing DIEA CTA were prospectively selected and randomly divided into two groups:group A(29 cases)and group B(30 cases).Group A was the conventional radiation dose group(tube voltage 120 kVp),the tube current was dose modulation 3,and the iterative reconstruction algo-rithm was Karl 5.Group B was the low radiation dose group(tube voltage 120 kVp),the tube current was dose modulation 2,with DLIR reconstruction algorithm,and four levels of DLIR(1-4)were reconstructed and labeled as groups B1 to B4.The mean tube current,vol-ume CT dose index(CTDIvol),and dose length product(DLP)of group A and group B were recorded,and the effective dose(ED)was calculated.The CT and standard deviation(SD)values of the external iliac artery and psoas major muscle were measured on axial images of each group,and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.Two observers using double-blind method independently evaluated the DIEA on volume rendering(VR)and maximum intensity projection(MIP)images of each group using a 3-point scale,and a 5-point scale was used to evaluate the overall image quality on axial images.Results Compared with group A,the mean tube current and ED in group B were decreased by 39.33％and 44.09％,respectively(P＜0.05).With the increasing of DLIR level from groups B1 to B4,the SD value of the image gradually decreased,while SNR and CNR gradually increased(P＜0.05).The CNR in groups B3 and B4 was higher than that in group A(P＜0.05).The subjective scores of the two observers were consistent(Kappa value 0.779-0.889,P＜0.05),and there was no statistical significance between group A and group B in the perforating vessels from the DIEA,intramuscular course,and the point of emergence(P＞0.05).With the increase in DLIR level,the subjective score of the overall image quality from group B1 to group B4 showed a trend of first increasing and then decreasing,and the score of group B3 was the highest(4.50±0.51)points,which had no statistical significance compared with group A(4.45±0.51)points(P＞0.05).Conclusion DLIR can effectively reduce the radiation dose of the DIEA CT A scan and ensure the image quality,among which DLIR 3 is the recommended best reconstruction grade.

Objective To investigate the influence of spectral CT monochromatic imaging technique on image quality and liver vol-ume measurement in computed tomography portal venography(CTPV).Methods A total of 120 patients who underwent contrast-enhanced abdominal CT examination were prospectively selected and randomly divided into group A and group B.The group A(n=60)was scanned with conventional parameters such as 120 kVp,Smart mA mode,and image reconstruction of 60％adaptive statistical iterative reconstruction-Veo(ASIR-V);while the group B(n=60)was with instantaneous switching 80/140 kVp,gemstone spectral imaging(GSI)Assist mode,and image reconstruction of 60％ASIR-V.In group B,six subgroups of images from 75 to 50 keV(with 5 keV interval)were recorded as subgroups B1 to B6.On the axial images,the CT values and standard deviation(SD)values of por-tal vein,liver and erector spinae were measured,and then the contrast-to-noise ratio(CNR)of portal vein and liver were calculated.The Liver Segmentation software was used to segment the liver in groups A and B,the liver volumes by automatic segmentation and manual segmentation(golden standard)were recorded,and then the volume difference rate was calculated.The overall image quality and automatic liver segmentation results were evaluated by two radiologists using a 5-point scale.Results In terms of overall image quality,subgroup B6 achieved the highest score and was superior to group A(P＜0.001).In terms of liver segmentation,subgroup B3 had the highest score and was superior to group A(P＜0.001).With the decrease of keV,the CT values,SD values and CNR of portal vein and liver in group B were gradually increased(P＜0.05),in which subgroup B6 was higher than that in group A(P＜0.001).The volume difference rate initially decreased and then increased with the decrease of keV.Except for subgroups B2 and B3,the differences were statistically significant between other subgroups and group A(P＜O.001),and the subgroup B3 had the lowest volume difference rate.Conclusion Spectral CT monochromatic ima-ging technique has an influence on CTPV image quality and liver volume measurement.The 50 keV images are the best for displaying portal vein,and the automatic liver segmentation volume of 65 keV images is closest to the real liver volume.

Objective To explore the application value of 1 024×1 024 reconstruction matrix combined with iterative reconstruc-tion algorithm(Karl)in deep inferior epigastric artery(DIEA)computed tomography angiography(CTA).Methods A total of 40 patients who underwent DIEA CTA were prospectively selected and the original data were reconstructed by grouping.Group A was reconstructed using a conventional 512×512 matrix combined with Karl 5 grade.Group B was reconstructed using 1 024×1 024 recon-struction matrix combined with Karl 5,7,and 9 grades,respectively,and 3 subgroups B1-B3 were obtained.The CT and standard devia-tion(SD)values of the external iliac artery and psoas major muscle were measured on axial images,and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.A 3-point scale was used to evaluate the perforating vessels from the DIEA,intramuscular course,point of emergence,superficial inferior epigastric artery(SIEA)and superficial inferior epigastric vein(SIEV)on volume ren-dering(VR)and maximum intensity projection(MIP)images by two observers,and a 5-point scale was used to evaluate the overall image quality on axial images.Results With the increase of Karl grade in groups B1 to B3,the SD value of the external iliac artery decreased gradually(P＜0.05),while SNR and CNR increased gradually(P＜0.05).The SD values of the external iliac artery in group B2 and group B3 were lower than those in group A(P＜0.05),and SNR and CNR were higher than those in group A(P＜0.05).There was a good consistency in the subjective evaluation between the two observers(Kappa values=0.773-0.872,P＜0.05).The perforating vessels from the DIEA,intramuscular course,point of emergence,SIEA and SIEV display and overall image quality subjective scores of group B2 and group B3 were better than those of group A(P＜0.05),and the scores of group B2 showed the greatest improvement.Conclusion The 1 024 × 1 024 reconstruction matrix combined with the Karl 7 reconstruction algorithm can optimize the image quality and improve the display of the DIEA and perforator microvessels.

Objective To investigate the clinical application value of posterior adaptive statistical iterative reconstruction-Veo(ASIR-V)algorithm combined with full-field organ dose modulation(ODM)technique in low-dose computed tomography urography(CTU).Methods Ninety patients who underwent urological contrast-enhanced and CTU examination were prospectively selected and divided into conventional dose group(group A,NI=11,posterior ASIR-V of 60％),low-dose group(group B,NI=15,posterior ASIR-V of 60％-100％with 10％interval,denoted as B1-B5 groups);full-field ODM low-dose group(group C,NI=15,posterior ASIR-V of 60％-100％with 10％interval,denoted as C1-C5 groups)according to the noise index(NI).The volume rendering(VR)and maximum intensity projection(MIP)images were reconstructed.The CT values and standard deviation(SD)values of the renal cortex and para-spinal muscles were measured,and the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were cal-culated.The CT values of the renal pelvis,ureter,and bladder were measured,and the SNR and CNR were calculated with the para-spinal muscles as background.The subjective score was performed on the two-dimensional and three-dimensional images to evaluate the ability of CTU to display lesions.The volume CT dose index(CTDIvol),dose length product(DLP),and effective dose(ED)of the three groups were compared.Results The bladder SNR and CNR of groups B1,C1,and C2 were lower than those of group A(P＜0.05).There was no statistically significant difference in the SNR and CNR of each tissue between groups B2,C3 and group A(P＞0.05).The SNR and CNR of each tissue in groups B4,B5,and C5 were higher than those in group A(P＜0.05).The display rate of lesions in urinary system in groups B2 and C3 could reach 100％.There was no statistically significant difference in the axial image scores between groups B2,C3 and group A(P＞0.05),while the VR and MIP image scores in each group were comparable to those in group A(P＞0.05).The CTDIvol of groups A,B and C were(6.08±2.11)mGy,(3.15±1.15)mGy,and(2.9±0.92)mGy,respectively.Conclusion CTU using the full-field ODM technique combined with posterior 80％ASIR-V can reduce the CTDIvol by 52.30％,and further reduce by 7.93％compared with group B,which is effective to reduce radiation to the gonads.

Objective:To explore the effects of the auto-prescription technique combined with noise index (NI) and adaptive statistical iterative reconstruction algorithm-veo (ASIR-V) on the radiation dose and image quality in the computed tomographic angiography (CTA) of the deep inferior epigastric artery (DIEA).Methods:The data of 150 cases who underwent DIEP CTA in the First Affiliated Hospital of Dalian Medical University were prospectively collected, and were randomized into groups A, B, and C, with 50 cases in each group. For group A, the conventional tube voltage was 120 kVp, and images were reconstructed using 40% ASIR-V. For group B, the tube voltage based on the auto-prescription technique was adopted, and images were reconstructed using 40%, 60%, and 80% ASIR-V (corresponding to the three subgroups B1-B3, respectively). For group C, the tube voltage based on the auto-prescription technique was employed, NI = 13, and images were reconstructed by 40%, 60%, and 80% ASIR-V (corresponding to subgroups C1, C2, and C3, respectively). Subsequently, the CT and SD values of the originating femoral artery of DIEA and the rectus abdominis at the same level as DIEA were measured on axial images of each group, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and the radiation doses of the three groups were recorded. Finally, the image quality and noise of DIEA in each group were independently and subjectively scored by two radiologists in a blinded manner.Results:Compared to group A, groups B and C exhibited higher CT values of femoral artery ( t= -5.18, -5.17, -5.06, -6.08, -6.08, -6.07, P < 0.05) and higher image SNR and CNR ( P < 0.05), which increased gradually with the upgrading of ASIR-V ( F = 55.45, 49.70, 53.47, 68.89, P < 0.05). The two radiologists offered consistent subjective evaluations (Kappa = 0.76-0.92, P < 0.05). The images of groups B and C displayed more distinct perforating branches and emerging points of DIEA and received higher subjective scores of intramuscular course compared to those of group A. The subjective scores of image noise in subgroups B2, B3, and C2 were not significantly different from those in group A. The radiation doses in groups B and C decreased by 15.10% and 52.85%, respectively compared to those in group A ( H = 75.21, P < 0.05). Conclusion:The combination of the auto-prescription technique with NI = 13 and 60% ASIR-V can reduce the radiation dose by 52.85% while ensuring a clear display of DIEA.

Objective To study the effect and mechanism of paeonol(PAE)on renal interstitial fibrosis in rats.Methods The rats were randomly divided into sham operation(Sham)group,unilateral ureteral obstruction(UUO)group,PAE low dose(PAE-L)group,PAE medium dose(PAE-M)group,PAE high dose(PAE-H)group and irbesartan(IRB)group.Except for the Sham group,the UUO model was established in other groups.Each group was given a corresponding intervention for two weeks.Serum creatinine(Scr),blood urea nitrogen(BUN),serum 8-hydroxydeoxyguanosine(8-OHdG)levels,renal tissue superoxide dismutase(SOD),glutathione peroxidase(GPX)activities,α-smooth muscle actin(α-SMA),type Ⅰ collagen(Col-Ⅰ),fibronectin(FN),silent information regulator 1(SIRT1),nuclear factor E2-related factor 2(Nrf2)protein expression were detected;observe pathological changes of kidney tissue and calculate collagen volume fraction(CVF).Results Compared with the UUO group,the serum levels of Scr,BUN,and 8-OHdG in each dose group of PAE were decreased,the activities of SOD and GPX in kidney tissue were increased,the positive expressions of α-SMA,Col-Ⅰ and FN in kidney tissue were decreased,and the protein expressions of SIRT1 and Nrf2 were increased.Masson staining showed a decrease of CVF in renal tissue(all P<0.05),and HE staining showed a different degree of improvement in pathological changes such as inflammatory cell infiltration and tubular dilatation in renal tissue;PAE improves renal interstitial fibrosis in rats in a dose-dependent manner(P<0.05),and the effect of large dose PAE on renal interstitial fibrosis in rats was similar to that of IRB.Conclusion PAE can alleviate UUO-induced rat renal interstitial fibrosis and oxidative stress,and improve rat renal function.And this mechanism may be related to the activation of the SIRT1/Nrf2 signaling pathway.

Purpose To explore the application value of 1 024×1 024 reconstruction matrix combined with iterative reconstruction algorithm(Karl)in computed tomography angiography(CTA)of gastric vessels and tumor-supplying arteries.Materials and Methods Thirty patients with gastric tumors who underwent clinical gastric CTA from March to June 2022 at the First Affiliated Hospital of Dalian Medical University were prospectively collected.The original data of CT scan images were grouped and reconstructed.Group A used the conventional 512×512 matrix combined with Karl-5 reconstruction;group B used 1 024×1 024 large reconstruction matrix combined with different levels of Karl algorithm reconstruction,obtaining three subgroups:B1(Karl 5),B2(Karl 7)and B3(Karl 9).The CT and SD values of abdominal aorta at the origin of the left gastric artery,celiac trunk,splenic artery,hepatic artery and the subcutaneous fat tissue of the abdominal wall were measured,and the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.The image quality of each group was assessed by two observers using a 5-point scale.Results The two observers had good consistency in the evaluation of image quality(Kappa=0.782-0.789,P<0.05).Subjective scores for groups B1 to B3 were all better than those for group A,with the highest score in group B2(two-dimensional scores:χ2=27.309,24.250;three-dimensional scores:χ2=21.964,21.294;all P<0.05).The gastric artery system was involved in tumor blood supply in 25 cases of 30 gastric tumors,with the clarity rate of each vessel in group B2 being superior to group A.There were no statistically significant differences in CT values of vessels between groups A,B1 and B2(t=-1.918-2.720,P>0.05),and apart from the SD of the abdominal aorta and CNR of the hepatic artery,differences in SD values,SNR,CNR,and background noise between group B2 and group A were not significant(t=-5.909-5.768,P>0.05);images from B1 to B3 showed a gradual decrease in SD values(F=2.881-27.109,P<0.05)and a gradual increase in SNR and CNR(F=3.612-12.149,P<0.05)as the level of Karl algorithm increased.Conclusion 1 024×1 024 reconstruction matrix combined with Karl-7 can improve the image quality and enhance the display effect of gastric microvessels and tumor-supplying artery branches,which have good clinical application value.

Purpose To explore the value of CT large reconstruction matrix 1024×1024 combined with iterative reconstruction algorithm Karl in the diagnosis of pulmonary nodules.Materials and Methods A total of 500 patients who underwent chest CT examination at the First Affiliated Hospital of Dalian Medical University from October 2021 to May 2022 were prospectively collected,and the raw data of CT scans were reconstructed to divide into group A and B.Group A was reconstructed using a conventional 512×512 matrix combined with Karl 5 reconstruction;group B was reconstructed using a large 1 024×1 024 reconstruction matrix combined with different levels of Karl algorithm to obtain four subgroups,including B1(Karl 6),B2(Karl 7),B3(Karl 8)and B4(Karl 9)subgroup.The signal-to-noise ratio was calculated by measuring the CT and standard deviation values of the tracheal lumen above the arch of the aorta(tracheal area)and the avascular area of the upper lobe of the left lung(lung parenchyma).The overall image quality of the lungs in group A and B was evaluated by two physicians.The best image quality subgroup in group B was compared with the lesion display in group A.The diagnostic efficacy was analyzed based on the surgical pathology results.Results In group B,the standard deviation values of trachea and lung parenchyma gradually decreased and the signal-to-noise ratio gradually increased as the Karl grade increased compared with group A(F=675.002-2 020.903,all P<0.05).All subjective scores in group B were significantly higher than those in group A(Z=-15.361--6.465,all P<0.05),and the highest subjective scores were found in group B4.Some solid nodules(≤3 mm)and solid nodules(6.1 mm-≤3 cm)showed no statistically significant difference in clarity(Z=-2.000,-0.378,both P>0.05).Compared with group A,group B4 showed a 12%-100%improvement in nodule clarity.Only pleural depression sign showed the difference was not statistically significant(χ2=2.143,P>0.05).Taking 43 cases of surgical pathology as the gold standard,the diagnostic accuracy of group B4 was 65.12%,which was better than that of group A,which was 41.86%(χ2=4.674,P<0.05).Conclusion The combined application of the large reconstruction matrix and the Karl iteration algorithm results in superior image quality and facilitates the diagnosis of lung nodules.

Objective To explore the feasibility of axial whole-liver one-stop examination with Revolution CT.Methods Totally 19 patients were underwent upper-abdominal enhanced examination with Revolution CT and acquired whole-liver CT perfusion (CTP),vein phase and balanced phase enhanced images.Two observers recorded the rank and peak CT value corresponding to time-density curve (TDC) of abdominal aorta and portal vein respectively on the CTP images.The perfusion parameters including blood flow (BF),blood volume (BV),hepatic arterial fraction (HAF),mean transit time (MTT),time to peak (TP) of left and right liver lobe were measured.The images of hepatic artery CTA and portal vein CTV were reconstructed and the arterial phase enhanced images were extracted using the images corresponding to abdominal aorta and portal vein peak TDC.And the radiation dose of CT perfusion and one-stop examination were recorded.The differences between perfusion parameters of left and right liver lobe were compared and the consistency of two observers were analyzed.Results The differences between BV and MTT of left and right liver lobe were statistical significance (both P＜0.05).The subjective scores of hepatic artery CTA,portal vein CTV and arterial phase images were greater than 1 point.The two observers were in great consistence (Kappa＞0.6).The effective radiation dose in perfusion phase and one-stop examination were 14.47 mSv and 21.29 mSv.Conclusion With low radiation dose,Revolution CT axial wholeliver perfusion one-stop examination can provide multiple quantitative parameters of liver CTP and clear hepatic artery CTA,portal vein CTV and 3 phase enhanced scan images,which has broadly prospective in clinical application.