64-slice Spiral CT Imaging In The Assessment Of Kidney Function In Normal And Hydronephrotic Kidney

PartⅠ:The Research of Perfusion Imaging Parameter, normal Perfusion Performance and The Influencing Factors in 64—Slice Spiral CT Kidney Perfusion ImagingObjective:①To investigate the methods of MSCT perfusion imaging of the kidney;②To measure all the cortex and medulla perfusion parameters of the nomal kidney;③These perfusion parameters were compared to determine whether there were significant diference between right and left,male and femal.And the correlation between age and perfusion parameters was analyzed.Methods:28 healthy volunteers were studied in this group with SIEMENS Sensation 64-slice spiral CT.A conventional kidney CT plain scan was obtained as a routine to locate the renal hili.Dynamic scans were performed at the location of the renal hili with 50ml nonionic contrast administration(300 mgI/ml) at the speed of 6 ml/s.There are three separate scan sequences for each patient with 30 seconds scan duration respectively.The patient was asked to breathe in and out during the 10s interval of each scan sequence.For each scan sequence,the rotation time is 0.5s,and scan interval is 0.5s,2.5s and 4.5s, respectively.Data postprocessing was performed on Siemens workstation using kidney analyzing software in the package of Body Perfusion.To measure all the cortex and medulla perfusion parameters of the nomal kidney.The perfusion parameters were then compared using the paired t-test and two-sample t-test,to determine whether there were significant diference between right and left,male and femal.And the correlation between age and perfusion parameters was analyzed. Result:①To explore the ideal 64-slice spiral CT kidney perfusion parameter combination.②The time-density curves of 28 bilateral normal renal cortex and medulla are symmetric,even coincident.The mean BF,BV,TTP,PS,PBV of renal cortex were 301.56±68.79ml/100ml/min,38.86±5.83 ml/100ml,11.17±1.12s,42.85±10.88ml/100ml/min,67.53±10.25 ml/100ml respectively.and the mean BF,BV,TTP,PM,PBV of renal medulla were 157.78±34.58 ml/100ml/min,28.53±3.90 ml/100ml,12.38±1.15s,75.59±22.68 ml/100ml/min,28.24±0.94 ml/100ml.③Using analysis of variance,there were no gender and right or left differences in the perfusion parameters(The P value of the BF,BV,TTP,PS,PBV of renal cortex were 0.55,0.73,0.60,0.16,0.68; The P value of the BF,BV,TTP,PS,PBV were 0.09,0.72,0.60,0.09,0.65.P＞0.05),but the perfusion parameters of cortex and medulla was lower in the elder(P＜0.05).Conclusion:①It can measure the cortex and medulla perfusion parameters of the nomal kidney with 64—slice spiral CT perfusion imaging.It can quantitatively evaluate the haemodynamics change in the normal renal tissue..②There were no gender and right or left differences in all the perfusion parameters of the normal kidney,but there were relationship between age with all the perfusion parameters. PartⅡ:64—Slice Spiral CT Perfusion Imaging in the Single Renal Functional Assessment of Hydronephrotic kidneyObjective:The purpose of this study was to evaluate the diagnostic value of MSCT perfusion imaging in assessment of single renal function of hydronephrotic kidney,and to compare the results with GFR which were obtained with SPECTMethods:64-slice spiral CT perfusion were performed in 36 obstructive nephrohydrosis patients whose split renal glomerular filtration rate(GFR) were measured by SPECT renal dynamic imaging.①To compared the perfusion parameters of the renal cortex and renal medulla of the Hydronephrotic kidney with the normal kidney studied in the primary part.②The 72 kidneys were divided into normal renal function,mild and severe renal impairment groups according to renal function.Differences between the groups respect to all the mean perfusion parameters of the renal cortex and renal medulla were assesses by ANOVA.③Using Pearsons correlation test,the correlation between all the mean perfusion.parameters of the renal cortex and renal medulla and renal GFR were examined.Result:①The time-density curves of bilateral normal renal cortex and medulla are not symmetric.The mean BF,BV,PS,PBV of renal cortex were 203.20±44.93ml/100ml/min,27.61±3.90 ml/100ml,30.68±6.48 ml/100ml/min,46.49±10.85 ml/100ml;and the mean BF,BV,PM,PBV of renal medulla were 99.89±24.08 ml/100ml/min,18.32±4.32 ml/100ml,51.80±12.09 ml/100ml/min,21.31±2.95ml/100ml.The mean Perfusion parameters of the cortex and medulla of obstructed kidney were lower compared to that of normal kidney.②There were significant differences of all the perfusion parameters of the renal cortex and medulla between three groups(P＜0.05).③The perfusion parameters of the renal cortex and medulla had positive linear corelation with GFR.The best correlatin was the blood flow of the cortex of kidney.The correlation coefficient r=0.852.Conclusion:①It can quantitatively evaluate the haemodynamics condition and functional lesion of the kidney using 64—slice spiral CT perfusion imaging;②It can classify the impaired kidney function;③The perfusion parameters of the renal cortex and medulla had positive linear corelation with GFR.So it is of certain value in evaluating the half renal function of hydronephrosis. PartⅢ:The 64-slice Spiral CT Study of Relationship between Renal Corticomedullary Differentiation,Contrast Between Renal Cortex and Medulla(CMC),Renal Cortex and Medulla Peak Value with the Single Renal Functional of Hydronephrotic kidneyObject:To observe 64-slice spiral CT perfusion imaging features about renal corticomednllary differentiation,differentiation contrast between renal cortex and medulla(CMC),renal cortex and medulla CT peak value in normal and hydronephrotic kidney,and to explore the relationgship between them with the single renal functional.Material and methods:64-slice spiral CT perfusion were performed in 36 obstructive nephrohydrosis patients whose split renal glomerular filtration rate(GFR) were measured by SPECT renal dynamic imaging. The 72 kidneys were divided into normal renal function,mild and severe renal impairment groups according to GFR.Renal corticomedullary diferentiation on CT images were divided into clear group,obscure group,part clear group and vanish group according to the level of CMD. The CT intensity of cortex and medulla was measured in order to calculate contrast between renal cortex and medulla(CMC),Using Pearsons correlation test,the correlation between them and renal GFR were examined.Results:①The 24 kidneys of normal group,24(100%) kidneys showed clear CMD.The 21 kidneys of mild renal impairment group, 14(66.67%)kidneys showed clear CMD,2(9.52%)showed obscure CMD and 5(23.81%) showed part clear of CMD;The 27 kidneys severe renal impairment group,7(25.93%)kidneys showed clear CMD,5(18.52 %)showed obscure CMD and 15(55.56%)showed part clear of CMD;②The normal group CMC was 0.616±0.203,The mild renal impairment group CMC was 0.517±0.140,The severe renal impairment group CMC was 0.367±0.110.The CMC had positive linear corelation with GFR,The correlation coefficient r=0.536.③The renal cortex and medulla CT peak value of normal group were 132.95±21.99Hu and 104.07±16.15Hu;The renal cortex and medulla CT peak value of mild renal impairment group were 90.97±29.32Hu and 75.90±24.70Hu;The renal cortex and medulla CT peak value of severe renal impairment group 68.45±24.09Hu and 56.90±21.31Hu.The renal cortex CT peak value had positive linear corelation with GFR,The correlation coefficient r=0.672, The renal medulla CT peak value had positive linear corelation with GFR,The correlation coefficient r=0.623.Conclusion:①The CMC and the renal cortex and medulla CT peak value all degrade when the kidney functiong decrease of obstructive nephrohydrosis patients.Hypofunction.②The CMC and the renal cortex CT peak value of obstructive nephrohydrosis had positive linear corelation with GFR.So they are of certain value in evaluating the single renal function of hydronephrosis. PartⅣRelationship between renal cortex thickness or volume and split renal function:study with CT measurementObjective To study the relationship between renal cortex thickness or volume and renal function,and to assess the value of CT as a criterion to grade renal function.Methods Enhancement CT were performed in 36 nephrohydrosis patients whose split renal glomerular filtration rate(GFR) were measured by SPECT renal dynamic imaging.The 72 kidneys were divided into normal renal function,mild and severe renal impairment groups according to renal function.Differences between the groups respect to the mean cortex thickness and volume were assesses by ANOVA.Using Pearson's correlation test,the corelation between the renal cortex thicknesses,volume and renal GFR were examined.Results The renal cortex thicknesses of normal renal function,mild and severe renal impairment groups were(0.51±0.1),(0.37±0.12),(0.23±0.80) cm respectively,and the renal cortex volume were (74.26±11.92),(55.28±15.19),(27.57±7.02)cm~3.There were significant differences of renal cortex thickness and volume between three groups (cortex thickness F=51.60,P＜0.01:cortex cortex F=77.01,P＜0.01),The thicknesses of renal cortex(r=0.778 P＜0.01),the volume of renal cortex (r=0.815 P＜0.01)had positive linear corelation with renal function.Conclusion The thicknesses and volume of renal cortex measured by CT can reflect renal function.CT was a supplementary method to a ssess renal function.