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Objective@#To explore the value of magnetic resonance fat quantification technology (MR mDixon-quant) in evaluating thyroid-associated ophthalmopathy (TAO) activity.@*Methods@#Case control study was performed.Fifty patients (100 eyes) with TAO which met Mourits criterion were enrolled from September 2016 to March 2018 in Ningxia Hui Autonomous Region People's Hospital.The TAO patients were grouped by clinical activity score (CAS). Twenty nine patients (58 eyes) with CAS≥3 served as TAO active group, twenty one patients (42 eyes) with CAS<3 served as TAO non-active group.Twenty three healthy subjects (46 eyes) were collected as normal control group at the same time.All subjects underwent orbital MR mDixon-quant and MR imaging.Orbital fat content (FF values) and exophthalmus was calculated on MR work-station.FF values and degree of exophthalmus were analyzed by analysis of variance.The correlation of FF values and CAS in TAO patients was conducted by Spearman rank correlation analysis.The cut-off values of FF in predicting TAO activity was determined by receiver operating characteristics (ROC) curve.The Kappa consistency test was chosen to assess the consistency of CAS and FF values.Intraclass correlation coefficient (ICC) were used to analyze the intra-observer and inter-observer repeatability of the FF values and the degree of exophthalmus.This study was approved by the Ethics Committee of Ningxia Hui Autonomous Region People's Hospital (No.20160718). All the candidates signed informed consent.@*Results@#The FF values were (85.190±4.346)%, (88.715±5.686)% and (82.345±5.445)% in TAO active group, TAO inactive group and normal control group, respectively, with a significant difference among the 3 groups (F=17.072, P<0.001). The FF values of TAO active group and TAO inactive group were significantly higher than that of control group, and the FF value of TAO active group was significantly lower than that of TAO inactive group (all at P<0.01). The degrees of exophthalmos were (20.221±1.714), (20.855±2.103) and (15.363±1.667)mm in TAO active group, TAO inactive group and normal control group, respectively, with a significant difference among the three groups (F=126.298, P<0.01). The degrees of exophthalmos in TAO active group and TAO inactive group were significantly higher than that in normal control group (both at P<0.01), there was no statistical difference in degrees of exophthalmos between TAO active group and TAO inactive group (P<0.05). Spearman rank correlation revealed that FF value was negative correlated with CAS (rs=-0.443, P<0.01). The cut-off value of FF value was 87.180%, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 74.14%(43/58), 66.67%(28/42), 75.44%(43/57), 65.12%(28/43) and 71.00%(71/100), respectively.There were consistencies of FF values with the CAS (Kappa=0.431, P<0.001). The intra-observe and inter-observer reproducibility were fairly good for FF value (ICC=0.953, 0.920) and degree of exophthalmus (ICC=0.935, 0.917).@*Conclusions@#MR mDixon-quant can quantitative measure orbital fat with good measurement repeatability.Fat quantification technology by MR is valuable in evaluating TAO activity.
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Objective To access the effects of 70 kV tube voltage combined with low dose and low concentration of contrast medium in coronary CT angiography (CCTA)by evaluating the image quality,radiation dose and contrast medium dosage.Methods Ninety patients suspected with coronary artery disease with body mass index(BMI)of less than 25 kg/m2and heart rate (HR)of less than 75 beats per minute were enrolled.The patients were randomly divided into three groups (n=30 for each group):Group A,100 kV of tube voltage with 370 mg I/mL iopromide,1 mL/kg;Group B,80 kV with 270 mg I/mL iodixanol,1 mL/kg;Group C,70 kV with 270 mg I/mL iodixanol,0.8 mL/kg.All the patients underwent CCTA with a 256 row wide-coverage volumetric CT.Automatic tube current modulation technique was applied.The images were reconstructed by adaptive statistical iterative reconstruction V (ASIR-V).The subjective image quality scores were compared with rank-sum test.The signal-to-noise ratio (SNR),contrast-to-noise ratio(CNR),effective dose(ED)and the total iodine intake were calculated and compared with one-way ANOVA.Results No statistically differences in age,gender,heart rate and BMI were observed among the three groups (P>0.05).Subjective image quality scores had no difference among the three groups (P>0.05).The CT values of group C were higher than those of group A(P<0.05).The image noise of group C was higher than that of group A and group B (P<0.05).No significant differences in SNR and CNR were noticed among the three groups (P>0.05).The ED of group B (0.39±0.08)mSv and group C (0.19±0.01)mSv were lower than that of group A (0.81±0.19)mSv (each P<0.05).Compared with group A,the decrease rates of ED of group B and C were 51.8% and 76.5% respectively.Compared with group A and group B,the total iodine intake of group C was decreased by 25% and 21.4% (P<0.05).Conclusion 70 kV of tube voltage combined with low dose and low concentration of contrast medium in CCTA can reduce the radiation dose and iodine intake without compromising image quality.
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Objective To investigate the abnormal region of gray matter and distribution in long-term night shift physicians of the emergency department,and explore the brain structural changes closely related to long-term chronic sleep loss.Methods The study was carried out among two groups of medical staff,with the chronic sleep deprived(CSD)group(n=15)performing a fixed night work and the regular sleep controls (RSC)group (n=15)working regularly during the day at our hospital.Both groups were age-and gender-matched.The data of two groups were analyzed using voxel-based morphometry (VBM)based on SPM8 to generate gray maps.Results Compared to the RSC group without night shifts,increased gray matter volume in the CSD group was observed in the middle temporal gyrus,inferior frontal fyrus,insula,thalamus,posterior cingulate,medial frontal gyrus,inferior parietal lobule and postcentral gyrus (P<0.05).Conclusion These findings suggest that long-term,chronic sleep loss is associated with the change of the gray matter volume in the network,and may have a neuroanatomical basis.The brain structural changes are related with the domains of emotion and language,this contributes to further explore on the neural mechanism of the effects of the long-term night shift on brain function.
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Objective To explore the image quality and diagnostic efficiency of coronary CTA (CCTA) in patients without heart rate (HR) control by optimizing acquisition phase with auto-ECG-gating technology using 256-row wide-volume detector.Methods Totally 200 patients with suspected coronary artery disease (CAD) were selected and underwent CCTA with auto-ECG-gating on a 256 row wide detector CT (Revolution CT).Patients were divided into 4 groups according to the real-time HR,group A (n=50):HR≤69 bpm;group B (n=50):HR 70-80 bpm;group C (n=50):HR 81-90 bpm;group D:HR≥91 bpm (n=50).CCTA images quality and diagnostic rate were assessed by two experienced radiologists blindly,and effective radiation dose were compared among 4 groups.Results There were no significant differences of age,sex,and body mass index among 4 groups (all P＞0.05),and there was significant difference of image quality score among 4 groups (P＜0.05).Totally,800 coronary arteries and 2 575 segments in 200 patients were assessed.There had no significant difference of diagnostic rate among four groups derived from the segment,coronary artery and patients (all P＞0.05).The effective radiation dose in A D groups were (1.05t0.48)mSv,(2.41± 1.20)mSv,(1.27±0.55) mSv,(2.66±1.12)mSv,and the difference was significant (F=29.22,P＜0.001).Conclusion It is feasible to perform CCTA in single cardiac cycle in patients with arbitrary heart rate by auto-ECG-gating using Revolution CT equipped widevolume detector.And it can improve image quality and success ratio in patients with moderate and high heart rate.
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Objective To investigate the value of quantitative dynamic contrast-enhanced MRI (DCE-MRI)in diagnosis of breast adenosis.Methods 54 patients with breast glandular lesions diagnosed as 4th or 5th grade in BI-RADS and proved by pathology un-derwent routine 3.0T quantitative DCE-MRI.Quantitative parameters including volume transfer constant (Ktrans ),plasma volume fraction (Vp )were measured.According to the pathological findings and MRI morphological characteristics,the lesions were divided into breast cancer group,adenosis group and control group.The contralateral healthy side of the adenosis group was regarded as control group.The quantitative parameters of the three groups were statistically analyzed.Results Pharmacokinetic parameters of Ktrans and Vp were (0.289±0.1 63)min-1 and 0.042 8±0.045 respectively in adenosis group (n=21),(0.959±0.45 1)min-1 and 0.057±0.079 in breast cancer group (n=33),and (0.048±0.022)min-1 and 0.01 6 ±0.01 9 in control group (n=21).Ktrans and Vp between adenosis and control group had statistical significance(Z =-5.733,-2.844,all P <0.05),Ktrans between breast cancer group and adenosis group had statistical difference (Z =-5.421,P =0.000 ).Vp between breast cancer and adenosis group had no statistical difference (Z=-0.009,P =0.993).Area under curve (AUC)of the receiver operator curve (ROC)to differentiate benign and malignant lesions of Ktrans were 0.941.When the cutoff were 0.304 min-1 ,the sensitivities and specificities were 93.9%,85.7%. Conclusion Quantitative DCE-MRI shows good diagnostic value in differentiation of breast glandular lesions and cancer.
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Objective To investigate and eompare the diagnostic values of linear reference region model (LRRM) and Extended Tofts model in quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) analysis of benign and malignant breast lesions under different temporal resolutions.Methods Eight five suspicious breast cancer women underwent bilateral DCE-MRI exam, 37 patients were benigns and 48 patients were malignants.Among those, 31 patients(15 malignant, 16 benign) were scanned with 18 s per phase, and 54 patients(33 malignant, 21 benign) were scanned with 7 s per phase, and they were assigned into breast cancer group, benign lesion group and healthy gland group proven by surgery or biopsies.For the same model, Ktrans values of the three groups under different time resolution were first analyzed using Kruskal-Wallis H rank sum test.Receiver operator curve (ROC) was used to analyse the diagnostic efficiency of K values.Results Under high and low temporal resolutions, K values of the healthy group were (0.048 ±0.022) and (0.090±0.040)/min for extended Tofts model,(0.301 ±0.197) and (0.287±0.225)/min for LRRM model respectively.K values of the benign group were (0.289±0.163) and (0.211 ± 0.080)/min for extended Tofts,(0.624 ± 0.358) and (0.593 ± 0.165)/min for LRRM respectively.K values of the malignant group were (0.959±0.451) and (0.524±0.285)/min for extended Tofts,(1.576±0.935) and (0.956±0.180)/min for LRRM respectively.There were significant differences among the three different groups(P＜0.05).Area under the ROC to differentiate benign and malignant breast lesions for Extended Tofts in high temporal, LRRM in high temporal, Tofts in low temporal and LRRM in low temporal were 0.941, 0.876, 0.850 and 0.933, with Ktrans cutoff values of 0.304, 0.917, 0.252 and 0.789/min,and sensitivity of 93.9％, 80.0％,80.0％, 80.0％;specificity of 85.7％, 90.5％, 81.2％, 87.5％ respectively.Conclusion Under low temporal resolutions, Ktrans of LRRM model had better sensitivities and specificities in differentiation of benign and malignant breast lesions than Extended Tofts model, which was the opposite in high temporal resolutions.
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Objective To explore the value of enhanced T2 *-weighted angiography (ESWAN) sequence in displaying the intracranial deep vein distension in full-term neonates with hypoxic-ischemic encephalopathy (HIE).Methods Thirty-two confirmed cases of full-term neonates confirmed with HIE and 10 cases of normal full-term neonates received the brain magnetic resonance imaging(MRI) ESWAN sequence scanning.The display rate of intracranial deep vein in normal group and HIE group with mild,moderate and severe degree was evaluated.The differences in intracranial deep vein display rate between the normal group and the HIE group or within different degrees of HIE patients were compared respectively to observe the relationships between intracranial ischemic lesion and deep vein conditions.The role of ESWAN sequence in the diagnosis of HIE was evaluated.Results The display rate of intracranial deep vein in normal group was 26.2％ (21/80 cases) ;the display rate of intracranial deep vein in mild,moderate and severe HIE groups were 59.8％ (67/112 cases),92.3％ (96/104 cases) and 95.0％ (38/40 cases),respectively.The differences of intracranial deep vein display rate between normal group and mild HIE group were statistically significant (P ＜ 0.05) ; the differences of intracranial deep vein display rate between the slight HIE group and moderate HIE group were statistically significant (P ＜ 0.05) ;the differences of intracranial deep vein display rate between the moderate HIE group and severe HIE group were not statistically significant(P ＞ 0.05).The distribution of intracranial deep vein distension and ischemic lesion in HIE group was consistent.Conclusions ESWAN sequence can clearly show the relationship between intracranial venous distension and ischemic lesion,which has diagnostic value in judging the location and extent of HIE.It can indicate the severity of HIE by displaying secondary distension of intracranial vein.
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Objective To explore the role of 256 CT iterative reconstruction in improving image quality and reducing radiation dose of carotid artery into cranial segment.Methods Sixty patients underwent head and neck CTA on a 256 CT scanner.Conventional dose scanning was performed in 30 patients using a filtered back projection (FBP) reconstruction (group A) and iterative iDose4 reconstruction (group B).Low dose scanning was performed in the other 30 patients using FBP reconstruction (group C) and iDose4 reconstruction (group D).The noise,SNR,CNR,score of image quality and effective radiation dose were evaluated in four groups.One-way ANOVA was used to analyze the image quality index between groups.Independent sample of Kruskal-Wallis test of ranked data was used to compare image quality score between groups.Paired t test was used to compare the effective radiation doses between the low dose group and conventional dose group.Results The image noise of four groups were 8.21 ±0.88,7.31 ± 0.33,11.17 ± 2.02 and 6.50 ± 0.49 respectively.SNR were 43.21 ± 4.49,5 1.83 ± 3.64,42.88 ± 9.19 and 53.47 ± 4.88,respectively.CNR were 37.88 ± 4.02,61.21 ± 6.31,36.63 ± 8.20 and 62.99 ±5.90,respectively.There were statistic differences (F =112.786,97.041 and 86.098,P ＜0.01).The differences of image noise between group A and B had no statistic significance,which was statistic different between group A and C (P ＜ 0.01).Except that the differences of SNR and CNR between group A and C,B and D had no statistic significance,the differences between other two groups had statistic significance (P ＜ 0.01).In case of image quality score of 1,2 and 3,there were 2,13 and 15 patients in group A; 0,7 and 23 patients in group B; 5,15 and 10 patients in group C; and 0,5 and 25 patients in group D.There was statistic differences of image quality score between each group (H =22.575,P ＜0.01).The effective radiation dose was (2.31 ±0.13) mSv in conventional dose group and (0.84 ±0.04) mSv in low dose group.There was statistic difference between the two groups (t =60.682,P ＜ 0.05).Conclusion Compared with conventional dose,iDose4 iterative reconstruction algorithms can obtain excellent images of CTA for carotid artery into the cranial segment with more than 50％ radiation dose decrease.
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Objective To determine the diagnostic value of double-phase enhancement and virtual endoscopy with multi-slice spiral CT (MSCT) on clinical staging of preoperative bladder cancer.Methods Seventy-five patients with bladder cancer diagnosed by fibercystoscope or operation. All of them were examined by double-phase enhancement and virtual endoscopy with MSCT. The images were analyzed and clinical staging were obtained. The findings of MSCT (71 cases)were compared with the post-operative histopathological results. Results There were 94 lesions to be found. The staging of MSCT: T1 26 cases,T2, 27 cases, T2b 13 cases, T3 12 cases, T4 16 cases. Histopathological results: pT1 28 cases, pT2a 24 cases, pT2b 14 cases, pT3 12 cases, pT4 16 cases. The sensitivity of preoperative staging on bladder cancer was 89.4 % (84/94) by double-phase enhancement of MSCT;the sensitivity of virtual endoscopy was 96.6% (84/87)for polyploidy tumors and 90. 9 % (10/11) for sessile lesions. When double-phase enhancement and virtual images were evaluated together, the sensitivity rate increased to 94.5%. When the tumors were confined within the bladder wall (≤T2b), the diagnostic accuracy of double-phase enhancement and virtual images was 91.2% (51/56). When the tumors had invaded the tissues and organs beyond the bladder wall (≥T3), the accuracy was 100% (28/28). Conclusion Double-phase enhancement and virtual endoscopy of MSCT is of great value in clinical staging of bladder cancer.