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Purpose To investigate the value of arterial spin labeling (ASL) in evaluating renal function in patients with renal cell carcinoma (RCC) after laparoscopic partial nephrectomy.Materials and Methods Fifteen patients with RCC undergoing laparoscopic partial nephrectomy were studied prospectively.The patients were performed ASL scan one week before and three months after operation.The correlation between renal blood flow (RBF) value measured by ASL and the glomerular filtration rate (GFR) measured by radionuclide method in the renal cortex of healthy side was analyzed.The RBF values in the kidney of affected side or healthy side were measured,the difference of which between before operation and three months after operation was compared.Results The RBF value and GFR data in the renal cortex of healthy side had positive correlation (r=0.638,P＜0.05).In the affected side of kidney,the RBF value of remaining renal tissue [(291.5 ± 37.3) ml/(100g·min)] compared with that of preoperative renal tissue [(237.8 ± 46.2) ml/(100g·min)]increased about 53.7 ml/(100g · min) (P＜0.05).In the healthy side of kidney,the RBF value of renal tissue [(241.1 ± 50.3) ml/(100 g · min)] compared with that of preoperative renal tissue [(290.4 ± 51.8) ml/(100 g·min)] decreased about 49.3 ml/(100 g·min) (P＜0.05).Conclusion ASL can be used to evaluate renal function,and it is valuable to evaluate renal perfusion function after laparoscopic partial nephrectomy of RCC.
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Objective To explore the correlationships between microperfusion diffusion indexes derived from intravoxel incoherent motion(IVIM)and perfusion values measured by arterial spin labeling (ASL)in renal allograft. Methods A total of 76 renal allograft recipients and 26 age-matched volunteers (group 0)were included in this prospective study. All subjects were underwent conventional MRI, IVIM and ASL MRI which were performed in the oblique-sagittal plane. Seventy-six recipients were divided into two groups based on the estimated glomerular filtration rate(eGFR):recipients with good allograft function(group 1, eGFR≥ 60 ml · min-1 · 1.73m-2,n=44)and recipients with impaired allograft function(group 2, eGFR0.05), but RBF value was significantly lower(P<0.05). The ADCslow, ADCfast, PF and RBF values of renal cortex were significantly lower in allografts with impaired function compared to allografts with good function(all P<0.01). In renal allografts, there were significant positive correlations between cortical ADCslow, ADCfast, PF, RBF value and eGFR(r values were 0.604, 0.552, 0.579 and 0.673, all P<0.01). Cortical ADCfast and PF value exhibited a significant correlation with RBF for recipients(r values were 0.501 and 0.423, all P<0.01). Conclusion Cortical ADCfast and PF values derived from IVIM and RBF measured by ASL show a significant positive correlation in renal allografts.
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Objectives To investigate the ability of T1 mapping and intravoxel incoherent motion imaging (IVIM) parameters for evaluating renal allografts at the early stage after renal transplantation. Methods This prospective study protocol was approved by the local ethics committee, and written informed consent was obtained from all subjects. Sixty two recipients 2 to 4 weeks after kidney transplantation and 20 healthy volunteers (control group) underwent routine MRI, T1 mapping, and IVIM imaging (11 b values, 0 to 700 s/mm2). Recipients were divided into two groups base on their estimated glomerular filtration rate (eGFR):37 recipients with good allograft function (eGFR≥60 ml·min-1·1.73 m-2) and 25 recipients with impaired allograft function (eGFR<60 ml·min-1·1.73 m-2). The ADC, true diffusion coefficient (ADCslow), pseudo-diffusion coefficient (ADCfast), perfusion fraction (f) and T1 values were measured on both cortex and medulla. Differences among groups were compared using the one-way analysis of variance. Correlations between eGFR and the parameters in renal allografts were assessed by using Pearson correlation analysis. ROC was performed to assess the diagnostic utilities of using these parameters to discriminate allografts with impaired function from good function. Results Excepting for cortical T1, ADCfast and medullary T1, f values, allografts with good function showed no differences in other parameters compared with healthy control. Excepting for medullary T1 and ADCfast,the other values showed significantly differences in allografts with impaired function compared to allografts with good function (all P<0.05). Excepting for medullary f and ADCfast values, allografts with impaired function showed significantly differences in the parameters compared with good function group(all P<0.05). In renal allografts, excepting for medullary T1, ADCfast, and f values, cortical T1 exhibited a negative correlation with renal function, and there was a significant positive correlation between eGFR and other parameters. Cortical T1 value showed high sensitivity(91.9%) to discriminate renal allografts with different function, with the threshold of 17.36 × 102 ms, and ADC value showed high specificity(96.0%)with the threshold of 1.98 × 10-3 mm2/s. Conclusion T1 mapping and IVIM technique may be useful for detecting renal allograft dysfunction, and be a reliable imaging for evaluating and monitoring allograft function.
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Objective To assess the value of arterial spin labeling(ASL) MRI in the staging of early renal allograft function. Methods Sixty two renal allograft recipients (2 to 4 weeks after kidney transplantation) and 20 age match volunteers were included in this study. All subjects underwent conventional MRI and ASL MRI which was performed in the oblique-sagittal plane. Recipients were divided into two groups according to the estimated glomerular filtration rate (eGFR), recipients with good allograft function (eGFR≥60 ml · min-1 · 1.73 m-2,n=37) and recipients with impaired allograft function (eGFR<60 ml · min - 1 · 1.73 m - 2,n=25). Renal blood flow (RBF) was measured and an intra-class correlation coefficient (ICC) was calculated to confirm the reproducibility of the measured results from two doctors. One-way analysis of variance (ANOVA) and Bonferroni were used to compare the different cortical RBF among three groups. Correlation of RBF with eGFR was evaluated using Pearson correlation coefficients. The receiver operating characteristic (ROC) curve was performed to assess the diagnostic efficacy of using cortical RBF to discriminate allografts with impaired function from good function. Results RBF values showed good reproducibility between doctors with an ICC larger than 0.90 in different group. Mean cortical RBF were (390 ± 61),(290 ± 69),(201 ± 86) ml · 100 g-1 · min-1 for healthy controls, recipients with good and impaired allograft function, respectively(F=37.313,P<0.01). RBF exhibited a significant correlation with renal function as determined by eGFR for recipients (r=0.60,P<0.01). Mean cortical RBF showed a high area under the ROC curve (0.773) to discriminate renal allografts with different function, with a sensitivity of 56.0% (14/25) and a specificity of 89.2% (33/37). Conclusion ASL MRI can assess the early renal allografts perfusion, and provide valuable information in the staging of renal function. It could be a useful method for evaluating renal function noninvasively.