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[Objective]To study the relationship between bridging septa thickening in the perinephric space and split renal function in acute unilateral upper urinary tract obstruction.[Methods]50 patients with acute unilateral upper urinary tract obstruction by calculus were analyzed retrospectively. According to the images of multi-slice spiral CT (MSCT)scanning,all cases were divided into thickened bridging septa group(n=25)and normal bridging septa group (n=25),The CT values of renal cortical in the plain(CTp)and renal cortical enhancing(CTe)phase were measured, the difference of increasement value(CTe-CTp)and the CT value ratio of the ipsilateral and opposite in renal cortical phase was analyzed by independent sample T test.[Results]The CT increasement value of bridging septa thickening and normal group were(103±30)HU and(128±24)HU respectively,the difference between the two groups was statistically significant(P<0.01);and CTac/CTuc were 0.81±0.13 and 0.96±0.06 respectively(P<0.01).[Conclusion]Thickening of bridging septa in the perinephric space with acute unilateral upper urinary tract obstruction will weaken the enhancement of renal cortical,and increased the likelihood of split renal function impairing.
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Objective To study the value of renal CT scan in evaluating split renal function.Methods 147 patients undergone CT scan from June 2009 to June 2011 were involved in this study.There were 73 cases of obstructive hydronephrosis and 74 cases of renal tumors.66 patients were males and 81 were females with a mean age of 53 years ( range 17 - 87 years).GFR detected by single-photon emission computed tomography (SPECT) was used as the reference of split renal function.The kidneys were divided into 3 groups according to the GFR:normal renal function (113 cases,GFR ≥ 34 ml/min),mildly impaired renal function (66 cases,GFR:20 -34 ml/min) and severely impaired renal function (41 cases,GFR ＜20 ml/min).One-way ANOVA and linear regression analysis were used to analyze the relationship between the results of CT scan and split renal functions. Results There were significant differences in the cortical thickness among the normal renal function,mildly impaired renal function and severely impaired renal function groups.The cortical thicknesses were (0.62 ±0.11) cm,(0.45 ±0.10) cm and (0.26 ±0.07) cm,respectively (P ＜ 0.01 ).The renal cortical thickness was strongly correlated with GFR (r =0.806,P ＜0.01 ).There were significant differences in the enhancement during the cortical phase among the 3 groups,which were (162.1 ±25.3) HU,(121.6 ±21.0) HU and (63.5 ±20.0) HU,respectively (P＜0.01).The enhancement during the cortical phase was strongly correlated with the GFR (r =0.851,P ＜ 0.01 ).The enhancement during the parenchymal phase and excretory phase was moderately correlated with the GFR ( r =0.467 and r =0.451,P ＜ 0.01 ). Conclusions The renal cortical tbickness and the enhancement during the cortical phase detected by CT scan might be useful for the clinical evaluation of split renal function.
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PURPOSE: Split renal function on diuretic renography has been considered to be a good tool for evaluating renal function, selecting treatment modalities and assessing efficacy of surgery in hydronephrosis, especially in ureteropelvic junction(UPJ) obstruction. However, contradictory supranormal function on renography has provided controversy with urologists. Is the phenomenon the result of fact or artifact? The authers thought that contradictory supranormal renal function measured with 99mTc-DTPA Is fundamentally related with a question. How accurately does the split renal function test represent the real renal function, namely, glomerular filtration rate(GFR)? To know relation of split renal function with real renal function(GFR) and to disclose clinical significance of contradictory supranormal renal function on diuretic renal scan, a prospective study was performed. MATERIALS AND METHODS: Diuretic renography was done in 14patients with upper urinary tract obstruction including UPJ obstruction, ureteral stone and lower urethral obstruction. Afer the first diuretic renography using 99mTc-DTPA percutaneous nephrostomy was performed on affected kidney, which was followed by the second diuretic renography. Endogenous creatinine clearance tests were done on the patients. Urine was collected through the nephrostomy tube, self voiding or indwelling Foley catheter, respectively So the endogenous creatinine clearance was determined respectively on both the renal unit. Also the endogenous creatinine clearance ratio of affected kidney was determined to compare with split renal function on renography. RESULTS: In 7patients, ratio of endogenous creatinine clearance on affected kidney was less than 40%. In the other 7patients, the ratio was more than 48%. In patients with less than 40% of endogenous creatinine clearance ratio on affected kidney, split renal function was overestimated by 10.3% to 27.5%(19.5+/-4.9%) comparing to endogenous creatinine clearance ratio. In the other 7patients split renal function had a little difference from endogenous creatinine clearance ratio (4.5+/-2.5%). The endogenous creatinine clearance ratio was not closely related with split renal function(correlation coefficients: 0.65). Split renal function of the first renography was closely related with that of the second renography(correlation coefficients: 0.88). Contradictory supranormal function occurred in 4cases. In 2cases it was real finding, in the other it was not. CONCLUSIONS: It appears that split renal function is overestimated in poor renal function and split renal function is closely related with real renal function in good renal function slate. Supranormal renal function is real finding in part, not in part. Clinical significance of split renal function should be cautiously and basically reevaluated through further study.
Subject(s)
Humans , Artifacts , Catheters , Creatinine , Filtration , Hydronephrosis , Kidney , Nephrostomy, Percutaneous , Pentetic Acid , Prospective Studies , Radioisotope Renography , Ureteral Obstruction , Urethral Obstruction , Urinary TractABSTRACT
PURPOSE: We evaluated whether increased split renal function ratio (%) on the renal scan with Tc-99m diethylenetriamine pinta-acetic acid (DTPA) represent elevated renal function in the obstructed kidney. MATERIALS AND METHODS: From 1994 to 1995, we evaluated 36 patients with unilateral hydronephrosis due to ureteropelvic junction (UPJ) obstruction and split renal function ratios of the affected kidneys were calculated using Tc-99m DTPA renal scan. RESULTS: Of the 36 patients, 7 patients showed that split renal function ratios of the affected kidneys were all over 52%. To assess the significance of the split renal function ratio on the Tc-99m DTPA renal scan, we performed Tc-99m mercaptoacetyltriglycine (MAG3) renal scan with the time interval of 3 days and calculated the split renal function ratios of the affected kidneys on the MAG3 renal scan in all 7 patients. The split renal function ratios of the affected kidneys on the MAG3 renal scan were also higher than those of the normal kidney. And the split renal function ratios of the affected kidneys on the MAG3 renal scan were well correlated with those of DTPA renal scan (r=0.83). CONCLUSIONS: Our results suggest that the increased split renal function ratio in affected kidney due to UPJ obstruction is not an artifact of the DTPA renogram.