| Purpose:Using two sample of 99 m Tc-DTPA plasma clearance as the reference standard evaluate the accuracy of glomerular filtration rate?GFR?valued by Renal dynamic imaging with four methods:CT renal depth correction and Tonnesen Formula.Method: Based on the new Chronic Kidney Disease?CKD?staging standard proposed by the American Kidney Disease Foundation in 2002,542 patients with concurrent renal dynamic imaging in our hospital were divided into 4groups,in which group A: GFR?90 ml/min,a total of 188 cases;group B: 60 ml/min?GFR<90ml/min,a total of 211 cases;group C: 30 ml/min?GFR<60ml/min,a total of 97 cases;group D: GFR<30 ml/min,a total of 46 cases.After radionuclide?99m Tc?-diethylenetriamine pentaacetic acid?DTPA?bolus-type iv injection of imaging agent,542 patients underwent conventional renal dynamics and immediately performed CT scan in both kidneys.The actual depth of both sides of the kidney was measured,and the time of 99 m Tc-DTPA injection was recorded,and the blood plasma was measured by blood drawing at 2h and 4h.The actual depth of the kidney was measured by CT.Then the actual depth of the kidney obtained by the CT measurement and the depth of the kidney assessed by the Tonnsson formula were substituted into the Gates method GFR measurement software,and the total GFR of the respective kidneysafter the depth of the kidney was measured.The statistical analysis of the left and right renal depths and the paired t-tests were performed by using the CT method to measure the depth of the kidney and the Tonnesen formula.The Pearson correlation analysis was performed on the CT measured kidney depth method,the Tonnesen formula and the double plasma method GFR.Bland-Altman method was used to compare the degree of deviation between the two methods and the double plasma method GFR.The GFR obtained from the double plasma method was used as the standard subgroup.The GFR values obtained from the two methods of the actual kidney depth method and the Tonnesen formula were compared with the GFR values obtained from the double plasma method.The paired t test was used.Result: The depths of kidney measured by both the CT method and the Tonnesen formula respectively in the left kidney was 7.05±1.12,5.63±0.51,t=19.625?p<0.001?,and in the right kidney was 7.23±0.87 and 5.67±0.51,t=20.513?p<0.001?.The GFRs of the double plasma method,the CT measured kidney depth method and the Tonnesen formula were: group A?95.99±13.69,92.69±14.36,82.7±15.2?,group B?76.0±8.4,83.4±16.3,66.5±14.5?,group C?45.7 ± 8.8,64.1 ± 16.8,50.9 ± 14.2?,group D?19.1 ± 6.8,35.0± 19.4,26.8 ± 16.5?.The total GFR values measured by CT measured kidney depth method and Tonnesen formula had good correlation with the double plasma method.The correlation coefficients were 0.763?P<0.01?and 0.660?P<0.01?,respectively.The mean values of difference about the GFR obtained from the CT measured kidney depth method and the Tonnesen formula comparied with total plasma GFR were: 6.83±18.79and-8.24±20.46,respectively;between the groups: group A?16.21 ±10.50,26.89±16.25,t=8.865?,group B?11.37±7.76,16.87±10.62,t=5.931?,group C?19.92±14.47,11.53±8.4,t=6.878?,group D?16.61± 13.25,10.84 ± 8.23,t=5.401?.The differences were statistically significant.Conclusion: The function of CT in SPECT/CT renal dynamic imaging is used to accurately measure the depth of both kidneys.It is easy to operate and helps to improve the accuracy and reliability of GFR measurement.Both CT depth-of-test kidneys and Tonnesen calculations have good correlation with plasma methods,but there were also differences.In the renal function normal and mild renal impairment groups,the accuracy of the measured kidney depth by CT was significantly higher than that of the Tonnesen algorithm.In severe renal function or renal failure,the correlation between the Tonnesen algorithm and the double plasma method is slightly better than that measured by the deep kidney method.While the difference of GFR between the CT measured renal depth method and the plasma method is small.And SPECT/CT tomography provides additional information for clinical diagnosis. |
PDF Full Text Request