RESUMEN
Objective To study the value of MR diffusion tensor imaging(DTI) in the staging of chronic kidney disease(CKD).Method MR diffusion tensor imaging was used on 26 CKD patients.All patients were diagnosed as CKD according to the criteria of clinical diagnostic.All MR images achieved diagnostic requirements.Diethylenetriamine pentaacetic acid(99mTc-DTPA) renal dynamic imaging was used to determine the unilateral renal function.CKD patients were determined as mildly renal impairment group and moderately to severely renal impairment group based on the glomerular filtration rate(GFR).Twenty healthy volunteers underwent DTI at the same time.The cortical and medullary ADC value and FA value were measured in all subjects who underwent conventional MRI and DTI.The paired Student's t test was used to compare the cortico-medullary difference of the mean ADC and FA values in all subjects.The oneway analysis of variance(ANOVA) was carried out to assess the difference among the medullary and cortical diffusion parameters(ADC,FA) of all the three groups,and LSD was used to assess multiple comparisons.The correlation of GFR and ADC value of the patients,and FA value of the patients were tested by Pearson correlation analysis.Results The cortical and medullary ADC values of 46 subjects were(2.25±0.25) × 10-3 and(2.10±0.20) × 10-3 mm2/s respectively,FA of them were(3.48±0.61) and(4.27±0.75) respectively(t =6.754,10.043 respectively; P＜0.01).The cortical ADC values of volunteers,mild renal impairment group,severely renal impairment group were(2.25±0.22) ×10-3,(2.31±0.19) ×103,(2.18±0.32) ×10-3mm2/s respectively.The medullary ADC value of the three groups were(2.09±0.19) × 10-3,(2.17±0.17) × 10-3,(2.06±0.24) × 10-3mm2/s respectively(F=0.968,0.882 respectively; P＞0.05).The cortical FA values of the three groups were 3.85± 0.47,3.18±0.62,3.20±0.52 respectively.The medullary FA of the three groups were 4.92±0.38,3.93±0.57,3.62 ± 0.53(F=8.725,33.705 respectively; P＜0.01).There was no correlation between cortical ADC,medullary ADC,cortical FA of the patients and GFR [(30.14±15.79) ml· min-1 · 1.73 m-2](r =0.243,0.197,0.196 respectively; P＞0.05).There was a positive correlation between medullary FA of the patients and GFR (r=0.556,P=0.003).Conclusion FA value has certain value in evaluating CKD early diagnosis and renal function.