Objective To explore the value of three-dimensional constructive inference in steady state sequence (3D-CISS se-quence)in case of midbrain aqueduct obstruction.Methods 46 cases with midbrain aqueduct obstruction were scanned with FLASH T1 WI、TSE T2 WI and 3D-CISS sequence at 3.0T superconductive MR scanner.The original images of the 3D-CISS sequence were reconstructed.The images of three sequences showing midbrain aqueduct obstruction were observed and analyzed.Results The de-tection rate of the midbrain aqueduct obstruction was 13% 、71.7% and 100% in FLASH T1 WI、TSE T2 WI and 3D-CISS sequence, respectively.The difference between the three sequences were significant (P <0.01 67).Conclusion 3D-CISS sequence shows mid-brain aqueduct obstruction more accurately.

Objective To explore the value of the apparent diffusion coefficient (ADC)of MRI diffusion-weighted (DW)in diag-nosing pathologic stage and histologic grade of bladder cancer.Methods 42 patients with confirmed bladder cancer underwent pelvic MRI examination including T2 WI and diffusion-weighted imaging (b values of 0 and 1 000 s/mm2 )Based on pathologic results,42 cases of bladder cancer were divided into three groups of Ta-T1 stage (non-muscle invasive),T2 stage (muscle invasive)and T3-T4 stage (around the bladder and other organizations invasive).Of 42 bladder cancers,36 urothelial carcinomas were divided into papillary urothelial neoplasm with low malignant potential (PUNLMP),low grade urothelial carcinoma and high grade urothelial carcinoma group.Tumor diameter and ADC were measured on DW imaging,and compared among different groups.Results The mean size of high grade tumors (4.52 ± 1.61)cm was significantly larger than that of PUNLMP (2.28 ± 0.51)cm and low grade tumors (1.69 ± 0.53)cm.The mean ADC of high grade tumors (0.83 ± 0.27)×10-3 mm2/s was significantly lower than that of PUNLMP (1.46 ± 0.30)×10-3 mm2/s and low grade tumors (1.17±0.11)×10-3 mm2/s (P<0.01).T3-T4 stage tumors showed significantly lower ADC (0.82±0.21)×10-3 mm2/s than T2 (1.01 ± 0.09)×10 -3 mm2/s and Ta-T1 stage tumors (1.24 ± 0.13)×10 -3 mm2/s (P <0.01).Conclusion DW ima-ging combined with conventional MR sequences is useful for displaying morphology of bladder cancer.DW imaging and ADC are use-ful in evaluation of pathologic stage and histologic grade of bladder cancer.

Objective To observe the feasibility of PC-cine MRI for estimating the cerebrospinal fluid circulation of fistula after endoscopic third ventriculostomy (ETV)in obstructive hydrocephalus.Methods 25 cases with obstructive hydrocephalus were scanned with routine MR protocol and PC-cine sequence before and after ETV.Qualitative and quantitative evaluation of the cerebro-spinal fluid flow through the fistula were performed and the results were compared with 25 cases of healthy volunteers.Results One week after operation,the cerebrospinal fluid flow through the fistula showed obviously positive in 23 patients,while negative in the other 2 patients,and the waveform was similar to that in the normal midbrain aqueduct.The outflow and inflow peak velocity of the cerebrospinal fluid through the fistula were lower than that in normal midbrain aqueduct(P<0.05),while the quantity of outflow,inflow and netflow were much higher(P<0.05).6 patients showed ventricular narrowing one week after operation and 17 cases maintained the same finding.During follow-up of half year,the ventricular size still showed no obvious narrowing in 14 patients.Ventricular expanding was observed in 2 post-operative patients.Conclusion PC-cine MRI can provide intuitive and reliable evidences in evaluation of ETV for obstructive hydrocephalus.

Objective:To explore the value of the static and dynamic pelvic floor MRI and diffusion tensor imaging (DTI) in evaluating the morphology and function of urethra in patients with stress urinary incontinence (SUI).Methods:From July 2020 to February 2021, a total of 28 patients with SUI and 45 age-matched healthy controls were prospectively collected at the First Affiliated Hospital of Zhengzhou University. The static and dynamic pelvic floor MRI and DTI were performed for all subjects. The thickness of internal and external sphincter of middle urethra were measured on static MRI images. The functional urethral length (FUL) was measured both on static and maximal strain phase of dynamic MRI images, then the difference of FUL was calculated. The presence of bladder neck funneling and urethra opening were observed on static and dynamic MRI. The muscle fiber bundle image of urethral sphincter complex was obtained by post-processing of DTI original images. The anisotropy fraction (FA), apparent diffusion coefficient (ADC) and three eigenvalues (λ1, λ2, λ3) of annular sphincter and central longitudinal muscle in middle urethra were measured. The independent sample t test and chi-square test were used to analyse the difference of measured parameters in MRI, parameters of DTI and imaging signs between the two groups. Results:Compared with healthy controls, the SUI patients showed that the thickness of external sphincter in middle urethral and FUL in static status and maximal strain phase were significantly decreased ( t=-3.95, -5.72, -8.41, all P<0.001), the difference of FUL between static status and maximal strain phase was significantly increased ( t=4.41, P<0.001). The positive rate of bladder neck funneling in static status and maximal strain phase, urethral opening in maximal strain phase of SUI group increased significantly (χ2=23.09 , 22.25, 26.59, all P<0.001). In SUI group, the FA value of middle urethral annular sphincter decreased significantly ( t=-3.48, P=0.001), while the ADC, λ2 and λ3 values increased significantly ( t=3.19, 2.15 , 2.06, and P=0.002, 0.038 , 0.046, respectively). There was no significant difference in DTI parameters of middle urethral longitudinal muscle between the two groups (all P>0.05). Conclusions:Static and dynamic MRI and DTI techniques can objectively evaluate the changes of urethral morphology and function of SUI patients. The thinning of the external sphincter in the middle urethra, shortening of the FUL and the destruction of the microstructure of the annular sphincter fiber bundle were the main alterations of SUI patients.

Objective To investigate the significance of blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) and ambulatory urodynamics monitoring (AUM) to find the cause of primary monosymptomatic nocturnal enuresis (PMNE) in children.Methods Thirty-seven children with PMNE (20 males and 17 females) were selected,with a mean age of (11.3 ±4.1) years old.A clinical management tool,3-day urination record,daytime BOLD-fMRI scan,conventional urodynamics (CUD) and AUM were performed respectively.Thirty-seven gender-age matched children(19 males,18 females) who would receive surgery treatment because of upper urinary tract disease and were confirmed to have no lower urinary tract dysfunction by CUD were enrolled as controls,with a mean age of (11.1 ± 2.9) years old,and 13 cases underwent BOLD-fMRI scanning.Results It was found that the ALFF value of the left middle frontal gyrus of PMNE was decreased and the ReHo value of the left superior occipital gyrus was increased compared with the control group by the resting BOLD-fMRI.The maximum voiding volume of PNME children was (303.11 ± 87.48) mL,the total urine volume at night was (568.65 ± 208.48) mL,and the nighttime bladder volume was (217.43 ± 81.53) mL.The incidence of maximum voiding volume reduction,nocturnal polyuria and decreased nocturnal bladder volume were 24.32％ and 56.76％,and 64.86％,respectively.However,AUM results showed that maximum detrusor pressure in the PMNE group was (39.22 ± 7.78) cmH2O (1 cmH2O =0.098 kPa),which was statistically significantly higher than that in CUD (32.22 ±9.00) cmH2O,and the difference was statistically significant (P ＜0.05).In PMNE group,29 cases (78.37％) had detrusor overactivity (DO),which was significantly higher than that in CUD group [16 cases (43.24％)],and the difference was statistically significant(t =-3.047,P =0.004).CUD and AUM were all detected in children with DO,the frequency of DO detected by AUM was significantly higher than that detected by CUD[(2.00 ±0.55 times/h) vs.(1.38 ±0.50) times/h,P ＜0.05],and the maximum amplitude of detrusor pressure when DO occurring was significantly higher in AUM than in CUD [(19.56 ± 6.01) cmH2O vs.(14.38 ± 3.07) cmH2O],and the differences were statistically significant (all P ＜ 0.05);however,there was no significant difference in bladder compliance detected by AUM or CUD (P ＞ 0.05).Conclusions The abnormal functions of the left middle frontal gyrus and left superior occipital gyrus,nighttime DO and the decrease of bladder capacity at night are considered to be key causes of enuresis in children with PMNE.AUM and resting state BOLD-fMRI evaluations are helpful in differentiating the pathogenesis of PMNE.