The Application Research Of3.0T MR Multi B-value Diffusion-weighted Imaging On The Kidney Of Normal And Diabetic Nephropathy

Purpose: To explore the ADC values of normal renal cortex andmedulla with multi b-value and to determine an optimal b value to visualisethe character of renal diffusion using diffusion-weighted MR imaging at3T.Methods:1,60cases of healthy volunteers who were Physical Check-Ups in ourhospital between September2012and March2013according to the standardof normal kidney were involved in the study.2, Adopting Discovery MR7503.0T,all subjects received conventionalMR and DWI examinations. DWI adopted a single trigger plane echosequence and saturated technology space with axial scanning. Multy b-valueswere included0,50,100,300,500,800,1000s/mm2. Using respiratorygating single breathless technology, scan time was20s, scan range covereddouble kidney.3, Apparent diffusion coefficien (ADC) values of multi b-values wereobtained with T2WI image as a reference by placing circular regions ofinterest in bilateral renal cortex and medullary using Functool AW4.4workstation software. ADC values for each b value were statistically analyzed.ADCs differences between the left and right kidney, between renal cortex andmedulla were analysed with paired Samples Test for each b value, P valueof less than0.05was considered to represent a significant difference.Results:1，With the increasing of b values, the signal-to-noise ratios of imaging decreased. When b value was800s/mm2, part of the images was slightdistortion, but the differences of cortex and medulla werel able to distinguish;when b value was1000s/mm2, the images were serious distortion and couldnot distinguish between cortex and medulla.2，With the increasing of b values, the ADC values decreased, and theADC values of cortex was greater than the medulla.When b value was50,100,300,500,800,1000s/mm2, the ADC values (×10-3mm2/s) of the normaladult kidney cortex were4.39±1.13、3.81±0.63、2.81±0.38、2.43±0.242.18±0.20、1.96±0.15， the ADC values (×10-3mm2/s)of the medullarywere3.94±1.05、3.34±0.64、2.57±0.35、2.25±0.22、2.04±0.21、1.88±0.13.There were significant differences between the cortex and medullaADC values for all the b values (all P<0.05).Conclusion:1, This paper showed the ADC values of normal kidney varied with thechanging of multi b-value and found the ADCs range of normal renal cortexand medulla of various b values at3.0T MRI. The ADC values could supplythe reference standard for nephropathy.2, At3T, rental cortex and medulla best visible on b=800，ADC withb=800was better to reflect the character of hydrone diffusion of the kidney. Purpose: To explore the differential diagnostic value of ADCs in earlydiabetic nephropathy and different stages with3.0T MR Multi b-valuediffusion-weighted imaging.Methods:1, Fifty-five patients with diabetic nephropathy (including34cases withearly DN group o and21cases with middle-late DN group) as well as60healthy volunteers (normal control group) were chose as the research objects.2, Adopting Discovery MR7503.0T,all subjects received conventionalMR and DWI examinations. DWI adopted a single trigger plane echosequence and saturated technology space with axial scanning. Multy b-valueswere included0,50,100,300,500,800,1000s/mm2. Using respiratorygating single breathless technology, scan time was20s, scan range covereddouble kidney.3, Using Functool AW4.4workstation software, all post-processingimages were automatically generated ADC figures by the workstation. WithT2WI image as a reference, we measured ADCs of bilateral renal cortex andmedullary.4，The differences of ADCs of renal cortex and medulla between earlyDN group, the middle-late group and normal control group were analized bySPSS17.0statistical software, and we also could evaluated differentialdiagnosis efficiency by ROC curve. Results:1，When b was50,100,300,500,800s/mm2, the ADC values (×10-3mm2/s) of the early DN group of renal cortex were4.30±1.12、3.66±0.65、2.70±0.19、2.31±0.17、1.99±0.19，the ADC values (×10-3mm2/s) of renalmedullary were4.03±0.85、3.32±0.47、2.50±0.19、2.10±0.15、1.84±0.18；the ADC values of the group DN middle-late renal cortex were3.87±0.95、3.24±0.36、2.53±0.21、2.13±0.13、1.86±0.18，the ADC values (×10-3mm2/s) of renal medullary were3.56±0.85、3.04±0.42、2.28±0.24、1.95±0.14、1.73±0.16.2, When b was50,100s/mm2, all the differences of ADCs of renal cortexand medulla between early DN group, the middle-late group and normalcontrol group were not statistically significant（P>0.05）. When b was300s/mm2,there were no statistically significant between early DN group andnormal control group（P=0.118>0.05）.Beyond that,all were statisticallysignificant differences between early DN group, the middle-late group andnormal control group under the rest b value(P<0.05).3, ADC values of cortex and medulla went down in turn among normalcontrol group, early DN group and the middle-late group with all b values（P<0.05）. When b was800s/mm2, there was the most significant differencebetween the three（P <0.01）.4, When b was800s/mm2, the diagnostic efficiency ADC values ofmedulla was higher than that of cortex between normal control group andearly DN group, sensitivity was71.7%and specificity was69.1%; thediagnostic efficiency ADC values of cortex was higher than that of medullabetween early DN group and the middle-late group, sensitivity was92.5%and specificity was42.6%, and the best diagnostic threshold of both types was1.905.Conclusion:1, With the increasing of b values, ADC values of cortex and medullawent down in turn among normal control group, early DN group and themiddle-late group, the ADC values was becoming more and more stable.2,3.0T MR Multi b-value Diffusion-Weighted Imaging could be usedfor the DN early diagnosis and differential diagnosis of DN in different stages,could be used as a clinical DN reference index of curative effect evaluationand disease development process. In this paper800s/mm2was the best valueusing for early diagnosis and differential diagnosis of DN stage.3, ADC values of renal cortex and medulla has a certain diagnosisefficiency in the diagnosis of DN and differential diagnosis of DN stage.