Objective Toinvestigatethevalueof3.0T MRreducedfield-of-view (rFOV)IVIM-DWIondistinguishingprostate cancerandprostatehypertrophy.Methods 30patientswithpathologicallyprovenprostatecancerand38patientswithprostatehypertrophy accordingtotheresultsofbiopsywereanalyzedretrospectively,whounderwent3.0T MRrFOV multipleb-valueDWIscanpreoperatively.The DWIscanwasperformedusing11b-valuesof0,30,50,100,150,200,400,800,1000,1500and2000s/mm2.ADC,slowdiffusion coefficient(D),fastdiffusioncoefficient(D?)andperfusionfraction(f)weremeasuredoncancerousfociandprostatehyperplasiafoci.Allofthe datawereanalyzed.Results TheADC,D,D?andfvaluesoftheprostatecancerwere(0.61±0.12)×10-3 mm2/s,(0.41±0.08)×10-3 mm2/s, (88.0±40.3)×10-3mm2/s,289.3%±29.4%,respectively,and(09.0±01.7)×10-3mm2/s,(05.4±01.3)×10-3mm2/s,(46.1±15.3)×10-3 mm2/s, 474.3%±10.85%,respectively,forprostatehypertrophy.Thedifferencesamongthefourparameterswerestatisticallysignificant(P<0.05).The areasofADC,D,D?andfvaluesunderROCcurvestodistinguishbetweenprostatecancerandprostatehypertrophywere09.32,08.27,01.58,0.976, respectively.Conclusion 3.0T MRrFOVIVIM-DWIcanreflectthetruewaterdiffusion motionandperfusionintheprostate,and maycontributetothedifferentialdiagnosisofprostatecancerandbenignprostatehyperplasia.

Assembling an adapted smoothing method and a classifier of wavelet transform combined support vector machine ( SVM) , a Raman spectrum recognition approach was built for low signal noise ratio situation. Firstly, spectra data were denoised by the adapted smoothing method. The smoothing window was adapted to the signal noise ratio, which would effectively remove noise with the intensity of the signal well remained. Secondly, the wavelet transform was used for dimension reduction of the data. The decomposition level of wavelet transform was optimized according to the best classification result of the training set. Lastly, SVM was used for classification. Cross Validation ( CV ) was applied to obtain the optimized parameters of SVM. Conditions for the effective parameters were searched considering the relation between the cross_validation result and the classification accuracy. Combined with the surface enhanced Raman scattering ( SERS ) technology , the developed spectrum recognition approach was used for qualitative analysis of methamphetamine ( MAMP ) and 3, 4_methylenedioxymethamphetamine ( MDMA ) in peopleˊs urine, where the detecting accuracy is above 95. 0%. The uniform Au nanorods (NRs) SERS substrate synthetized by the Hefei Institute of Intelligent Machines of Chinese Academy of Sciences was used for the experiment. Raman spectra were acquired using an Inspector Raman ( DeltaNu) spectrometer, with the excitation wavelength of 785 nm and the integrate time of 5 seconds.

Objective To investigate the role of dual-source parallel radio frequence (RF) and single-source excitation in liver imaging at 3.0 T MR.Methods This study was a retrospective analysis.One hundred and seven subjects underwent a 3.0 T TX MR scanning including axial spectrally selective attenuated inversion recovery (SPAIR) T2WI,axial DWI and coronal balanced-fast field echo( Balanced FFE).Each sequence was carried out with both single-source and dual-source RF excitation.Student＇s t test was used to compare the differences between single-source and dual-source RF excitation in the image uniformity,signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR).Wilcoxon signed rank test was used to determine whether there was difference between conventional and parallel transmission in the score of image quality.Reader agreement was assessed using the Cohen＇s Kappa test.Results For the image uniformity,there was significant difference between single-source and dual-source excitation (418.40 ± 66.75 for single-source vs.416.26 ± 50.61 for dual-source,t =2.524,P ＜ 0.05 ).There also existed significant difference between single-source and dual-source excitation in SNR and CNR,respectively.The SNR and CNR of parallel transmission (22.03 + 12.16 and 18.33 ± 10.01,respectively) were both higher than those of single transmission (20.36 ± 11.21 and 15.22 ± 8.95,respectively) ( t =- 2.630,P ＜ 0.05 for SNR and t =- 4.238,P ＜ 0.05 for CNR).Image quality comparisons revealed significantly better results with dual-source than single-source RF excitation at SPAIR T2 WI ( 1.40 + 0.42 vs.1.81 ± 0.27 ),DWI ( 1.08 ± 0.40 vs.1.63 ± 0.36 ) and Balanced FFE sequence ( 0.95 ± 0.45 vs.1.65 ± 0.37,Z =- 5.894,- 5.801 and - 6.985,respectively,P ＜ 0.01 ).In the comparison of image quality,the agreement between the two readers was very good ( Kappa ＞ 0.8,P ＜ 0.05 ).Conclusion Dual-source parallel RF excitation MR imaging in liver enables reducing dielectric shading,improving homogeneity of the RF magnetic induction field,and increasing SNR and CNR at 3.0 T.