Objective To observe the influence of different acceleration factors(AF)on compressed sensing susceptibility weighted imaging(CS-SWI)for cerebral medullary veins of healthy people,and to screen the best AF.Methods Forty healthy volunteers were prospectively enrolled.Axial brain SWI images were obtained with CS technique under different AF(AF0,CS2,CS4,CS6,CS8 and CS10),and the phase value(PV)and standard deviation(SD)of bilateral septal vein(SV),internal cerebral vein(ICV),thalamus vein(TV),basal vein(BV)and dentate nucleus vein(DNV)were measured.Taken PV and SD of parietal white matter as controls,the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of venous images were calculated.Then the original images were reconstructed with minimum intensity projection,and the subjective quality scoring of reconstructed images were performed using a 5-point scale.SNR,CNR,PV and quality score were compared among images under different AF,and the best AF,i.e.with the best performances for displaying and quantitatively analyzing cerebral medullary veins in healthy people was obtained.Results Compared with those acquired with AF0,SNR and CNR of all cerebral medullary veins acquired with CS6,CS8 and CS10 were significantly different(all adjusted P＜0.05).Meanwhile,significant differences of PV in bilateral SV and right TV were found among CS6,CS8 and CS10,also in bilateral ICV,left TV and bilateral BV between CS8 and CS10(all adjusted P＜0.05).Conclusion Excessive AF might decrease image quality of CS-SWI for cerebral medullary veins.CS4 was the best AF for displaying and quantitatively analyzing cerebral medullary veins in healthy people.

Objective To explore the impact of δ-catenin expression level on resting-state brain function in breast cancer patients.Methods Totally 104 female breast cancer patients were prospectively enrolled and divided into δ-catenin high expression group(DH group,n=51)and δ-catenin low expression group(DL group,n=53)according to δ-catenin expression level,while 36 female healthy volunteers were selected as controls(control group).Neuropsychological tests were performed,and resting-state functional MRI(rs-fMRI)were acquired,then parameters of brain function,including amplitude of low frequency fluctuation(ALFF),fractional ALFF(fALFF),regional homogeneity(ReHo)and functional connectivity strength(FCS)of brain regions with differences among groups were obtained.Spearman correlation analysis was used to evaluate the correlations of function parameters of brain regions with general data and neuropsychological test scores.Results Significant differences of fALFF,ReHo and FCS values were found among 3 groups(familywise error rate[FWE]correction,all P＜0.05).fALFF value of left inferior temporal gyrus in DH and DL groups were both higher than that in control group(FWE correction,both P＜0.05),ReHo value of right inferior temporal gyrus in DH group,as well as of right middle temporal gyrus,right inferior temporal gyrus and right fusiform gyrus in DL group were all lower than that in control group(FWE correction,all P＜0.05),FSC value of left lenticular nucleus,left putamen,left fusiform gyrus,left calcarine fissure surrounding cortex and left inferior temporal gyrus in DH group were all higher than that in DL group(FWE correction,all P＜0.05),FSC value of left lenticular nucleus,left putamen,left fusiform gyrus and left calcarine fissure surrounding cortex in DH group were all higher than that in control group(FWE correction,all P＜0.05),while FSC value of left lingual gyrus,left lenticular nucleus and left putamen were both higher than that in control group(FWE correction,both P＜0.05).In brain regions with different fMRI indexes between DH group and DL group,FSC values were lowly positively correlated with CogPCA results(r=0.313,P＜0.05).In brain regions with different fMRI indexes between DH group and control group,fALFF value were lowly positively correlated with trail making test A(TMT A)and trail making test B(TMT B)(r=0.301,0.310,both P＜0.05),ReHo values were lowly negatively correlated with TMT B(r=-0.307,P＜0.05),FCS values were weakly/lowly positively correlated with TMT A and TMT B(r=0.282,0.309,both P＜0.05)and lowly negatively correlated with results of digital symbol substitution test(DSST)(r=-0.363,P＜0.05).In brain regions with different fMRI indexes between DL group and control group,fALFF values were weakly/lowly negatively correlated with results of mini mental state examination(MMSE),Montreal cognitive assessment(MoCA),auditory verbal learning test(AVLT)short-term memory and DSST(r=-0.399,-0.362,-0.344,-0.288,all P＜0.05).Conclusion The expression level of δ-catenin had certain impact on brain function of breast cancer patients,resulted in asymmetry changes of brain network in bilateral hemispheres,as well as memory loss through affecting left inferior temporal gyrus,left lenticular nucleus,left putamen and left fusiform gyrus.

Objective:To explore the value of echo-planar imaging correction (EPIC) for improving image quality of diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) of cervical cord.Methods:A total of 33 subjects (20 males, 13 females) were scanned on a 3.0 T MR scanner from January to March 2022, and the sequences included T 1WI, DWI and DTI (with and without corrections). Two observers delineated the regions of interest (ROIs) on the fused images of DWI and DTI with T 1WI before and after correction, and measured the average diffusion coefficient (ADC), fractional anisotropy (FA), and offset distance of ROIs between images with and without corrections. The subjective scores of image quality were also evaluated. The ICC or Kappa was used to test the consistency of the quantitative measurement and subjective scores by the two observers. The average values by the two observers would be used for subsequent analysis. The independent pair t-test and Wilcoxon test were used for comparison of objective measurements and Mann-Whitney U test was used for subjective image assessments between images with and without corrections. Results:The measurement data and the subjective scores of the two observers were in good agreement (ICC 0.912-0.999, Kappa 0.778-0.816). The independent sample t-test showed the subjective scores were significantly different for the DWI and DTI images between before and after geometry and/or ADC corrections. The ADC values of C6, the offset distances measured by DWI before and after correction of C4, C5, and C6 and subjective scores were significantly different ( P<0.05); The FA values of C1 and C3, ADC values of C1 and C3, offset distance of C4, C5 and C6 measured by DTI before and after correction and subjective scores were statistically significant ( P<0.001). Conclusion:EPI geometry correction and ADC value correction can significantly reduce geometric distortion, increase image quality, and thus improve the diagnosis accuracy of essential diseases.

Paroxysmal supraventricular tachycardia includes atrioventricular node reentry tachycardia, atrioventricular reentry tachycardia and atrial tachycardia.At present, the commonly used methods in clinical diagnosis include ventricular pacing in tachycardia, pre ventricular stimulation in refractory/non refractory period of his bundle, pacing in different parts of the atrium, parahisian pacing in sinus rhythm and stimulation in different parts of the ventricle.Ventricular pacing is one of the most commonly used methods in clinical diagnosis.However, it may lead to " false V-A-A-V" sequence after pacing.The ventricular pre phase stimulation of his bundle refractory period may appear false negative or lead to termination of tachycardia, which is not condutive to differential diagnosis.The results may be affected by pacing position, bypass position and refractory period when parahisian pacing and ventricular stimulation at different sites/frequencies are performed in sinus rhythm.Because of their respective advantages and limitations, it is necessary to integrate a variety of identification methods to improve the accuracy of diagnosis and the success rate of operation.

Objective:To investigate the electrocardiographic characteristics of left and right ventricles origin of premature ventricular contractions(PVCs) during V3 transition of precordial leads, right ventricular outflow tract (RVOT) anterior septum and right coronary sinus (RCC), and RVOT middle-posterior septum and left coronary sinus (LCC).Methods:From January 2017 to September 2019, 91 patients with ventricular extrasystole of outflow tract who had V3 transition in precordial lead and had successful radiofrequency ablation in RVOT anterior septum, middle posterior septum, LCC and RCC were selected for retrospective case control study.The electrocardiography measurements of PVCs were compared between the anteroseptal RVOT group and RCC group, as well as the middle-posterior septal RVOT group and the LCC group, respectively.The measurements included the R-wave amplitude in lead Ⅰ, Ⅱ, Ⅲ and aVF, R amplitude ratio in leads Ⅲ to Ⅱ, Q-wave amplitude in lead aVL and aVR, Q amplitude ratio in leads aVL to aVR, R-wave and S-wave amplitude from leads V1 to V3, the V2S/V3R index, the transition zone index, and the V2 transition ratio.Results:Thirty-six cases originated from the anteroseptal RVOT, and 11 from the LCC.Lead I R-wave amplitude in anterior septal RVOT was higher than LCC group((0.22±0.25) mV vs.(-0.17±0.33) mV; P=0.003). R-wave amplitude in lead Ⅱ was lower than that in the LCC group((1.59±0.35) mV vs.(1.76±0.27) mV; P=0.035). R-wave amplitude in lead aVF was lower compared with the LCC group((1.53±0.35) mV vs.(1.78±0.39) mV; P=0.050). The V2S/V3R index showed a significant difference between these two groups(1.99±0.66 vs.0.76±0.38; P<0.001). The V2 transition ratio also appeared a significant difference between the two groups(0.69±0.43 vs.1.05±0.35; P=0.005). PVCs arose from the middle-posterior septal RVOT in 32 cases, and from the RCC in 12 cases.Compared with RCC group, lead Ⅰ R-wave amplitude showed lower ((0.25±0.31) mV vs.(0.57±0.12) mV; P<0.001); R amplitude ratio in leads Ⅲ to Ⅱ higher (0.89±0.14 vs.0.72±0.18; P=0.002); Q amplitude in lead aVL((0.72±0.24) mV vs.(0.51±0.16) mV; P=0.002)higher, and Q amplitude ratio in leads aVL to aVR higher in the middle-posterior septal RVOT(0.76±0.23 vs.0.50±0.21; P=0.002). Conclusion:Among the cases with lead V3 transition, PVCs originated from the anteroseptal RVOT show significantly different R wave in lead Ⅰ, Ⅱ, aVF, V2S/V3R index, and the V2 transition ratio compared with those from the LCC.The PVCs from the middle-posterior septal RVOT and the RCC have different R wave in lead Ⅰ, R amplitude ratio in leads Ⅱ and Ⅲ, Q amplitude ratio in leads aVL and aVR.Combined with its different characteristics, it can help to identify the origin of left and right ventricles.

Objective:To assess the value of amide proton transfer weighted (APTw) imaging in the evaluation of pH changes in infarct core (IC) and ischemic penumbra (IP) in subacute cerebral infarction.Methods:The data of twenty-three subacute cerebral infarction patients with unilateral steno-occlusive disease of the middle cerebral artery (subacute infarction group) from April to November 2019 in the First Affiliated Hospital of Dalian Medical University were prospectively analyzed. Fifteen healthy volunteers were enrolled in this study as the control group. All subjects underwent conventional MRI, DWI, 3D-pseudo continuous arterial spin labeling (3D-pCASL) and APTw sequences. Based on DWI images, relative cerebral blood flow (rCBF) and APTw images to determine the region of IC, blood flow penumbra [cerebral blood flow(CBF)-DWI mismatch area, IP CBF] and metabolic penumbra (APTw-DWI mismatched area, IP APT). 3D ROIs were used to semi-automatically measure the APTw signals and the volume of IC and IP CBF of the patients in subacute infarction group. The comparison of APTw signals between the infarct side and the contralateral side in the subacute infarction group, the comparison of bilateral APTw signals in the control group, and the comparison of APTw signals in the IC and IP CBF regions were performed by paired-sample t test or Wilcoxon signed-rank test. The paired-sample t test or Mann-Whitney U test was used to compare the APTw signals between the two groups. The Friedman test was applied to compare the difference of volumes among IP CBF1.5, IP CBF2.5 and IP APT . Results:There was no significant difference of the APTw signals among the IC, the contralateral side in the subacute infarction group and the control group ( P>0.05). The APTw signals of IP CBF and IC of the infarction group were statistically different ( P<0.05). Compared with the contralateral side of IP CBF1.5 (3.7±1.7, -1.84±1.48, 5.57±2.75), the APTwmax (3.07±1.41, t=-3.012, P=0.006), APTw min [-1.30 (-1.74, -0.57), Z=-2.099, P=0.036], and APTwmax-min(4.51±2.58, t=-3.273, P=0.003) signals in the IP CBF1.5 were decreased ( P<0.05). Compared with the contralateral side of IP CBF2.5 [-1.53 (-2.80, -0.91), 5.31±2.61], the APTw min [-1.08 (-1.60, -0.49), Z=-2.616, P=0.009] and APTwmax-min (4.41±2.72, t=-3.228, P=0.004) signals in the IP CBF2.5 were decreased. The volumes of IP CBF1.5 [107.51(50.08, 138.61)mm 3], IP APT [99.00 (53.27, 121.335) mm 3] and IP CBF2.5 [89.91 (51.53, 139.87) mm 3] were successively reduced (χ2=7.913, P=0.019), and the volume of IP CBF2.5 was significantly smaller than that of IP CBF1.5 ( P=0.037). Conclusion:The acid-base metabolism in the IC of subacute cerebral infarction is not obvious, but the blood flow penumbra has local acid-base metabolism imbalance, and the range of metabolic penumbra coincides with the blood flow penumbra.

Objective To observe whether catheter ablation for ventricular premature complexes (PVC) has an effect on ventricular diastolic function in elderly patients.Methods Elderly patients older than 65 years of age who underwent catheter ablation from March 2012 to May 2015 for idiopathic ventricular premature complexes were enrolled.Preoperative echocardiography was performed using E／e′ for left ventricular diastolic function and venous brain natriuretic peptide (BNP) levels were measured.All patients underwent catheter ablation under the guidance of a three?dimensional mapping system.Cardiac ultrasound and BNP levels were repeated 6 months after ablation, and 24?hour electrocardiogram was performed to confirm ventricular premature complexes.Results There were a total of 89 patients with idiopathic ventricular premature complexes ( PVC) who underwent catheter ablation.81 cases were successed at 6 months,with a success rate of 91.0%.At 6 months after ablation,the E／e′ values were significantly lower ((15.3±5.2) vs ( 10.2± 3.2),( P＜0.001)) and BNP levels were significantly lower (( 202.0 ± 23.2) pg／L vs (94±13.3) pg／L),(P＜0.001).For the unsuccessful subgroup,there was no significant change in E／e′values (16.3±6.3 vs 15.2±5.6) and BNP levels ((223.0±26.8) pg／L vs (245.0±23.9) pg／L), (P＞0.05).Conclusion The number of premature ventricular beats is associated with left ventricular diastolic function,and ventricular premature catheter ablation can improve left ventricular diastolic function in elderly PVC patients.

Objective To make correct diagnosis for Rathke cleft cyst(RCC)and cystic pituitary adenomas(CPA)through retrospective analysis of characteristics of MRI.Methods RCC (n=30)and CPA (n=30)confirmed by surgery and pathology were analyzed retrospectively.Following characteristics of lesions were observed:morphology,size,location,range,T1WI signal intensity and patterns of enhancement,presence of intracystic fluid level,septum,nodule,hypointense rim on T2WI and change of the pituitary stalk.The independent sample t-test and χ2 test were used respectively to analyze differences between two groups of continuous variables and categorical variables.Results Most of RCC were oval,less than 2 cm3,under the optic chiasm and within the bilateral cavernous sinus,various for signal intensity,without or with thin-walled contrast enhancement.Intracystic nodule accounted for 40% of cases and there were double cystic nodules in 1 case.Obvious contrast enhancement of intracystic nodule was found in 1 case.Pituitary stalk was in center.Most of CPA were snowman shaped,bigger than 2 cm3,off middle line location,with compression of the optic chiasm and sellar base,had thick-walled contrast enhancement,with intracystic fluid level and septum,had hypointense rim on T2WI.The pituitary stalk was shifted.Conclusion The MRI findings of RCC and CPA are significant differences in the shape,size,intracapsular structure,enhanced performance and changes of surrounding structure.

Objective To optimize protocol in one-stop whole brain CT perfusion imaging (CTP) combined with CTA.Methods Totally 45 subjects underwent one-stop whole brain CTP combined with CTA with three different scanning protocols and 22 phases.CTA images were reconstructed from CTP original data at the tenth phase,the protocols of three scanning groups were as follows:Group A using automatic tube current modulation technique (ATCM) with low noise index (NI;NI=2),group B with fixed tube current (325 mA) and group C using ATCM with slightly low NI (NI=2.5),and the other phases of three groups were performed with ATCM and NI=8.Tube voltage of all three scanning protocols was 100 kV.The radiation dose and related parameters were recorded.Objective parameters including image noise (SD),SNR,CNR and perfusion parameters in different parts of the brain parenchyma and subjective scores of CTA,CTP image quality were compared among three groups.Results There was significant difference of effective dose (ED) among three groups (P＜0.05).ED of group A was higher than that of group B and C (P=0.043,0.001).No difference was found in CTA image noise,SNR,CNR nor subjective scores among three groups (P=0.218,0.545,0.575,0.900),neither of CTP images among three groups (P＞ 0.05).Conclusion Using ATCM and increasing NI appropriately may reduce radiation dose in one-stop CTP combined with CTA.

Objective To evaluate CT imaging and pathological features of maxillofacial malignant myoepithelioma (MME). Methods A total of eight patients with pathologically confirmed MME of the maxillofacial region were underwent non-enhanced and contrast-enhanced CT scans.CT features of the lesions were assessed as follows:location,number,shape,size,enhancement pattern and CT number on non-enhanced and contrast-enhanced scan.CT features were compared with the pathological results.Results All the lesions were unilateral,in which mixed type with clear cells and spindle cells in 5 cases,mixed type with epithelioid cells and plas-ma cells in 2 cases,and clear cell type in one case.8 cases were manifested as lobulated mass.On non-enhanced scan,the density of all the lesions were hetergeneous with cystic area,1 case with calcification and 2 cases with bone destruction.On the contrast-en-hanced CT,all the lesions were showed hetergeneously moderate or obvious enhancement,and cystic,line and crack areas without the enhancement were observed.Minor vessel and spiculate protuberance of marginal zone on the arterial phase were observed in most le-sions.Conclusion MME has different pathological subtypes and characteristic CT features.CT is an effective method to diagnose MME.