SPECT and CT in Evaluating Preoperative Renal Function of Patients with Unilateral Hydronephrosis / 中国医学影像学杂志

ABSTRACT

Purpose To analyze the relationships between glomerular filtration rate (GFR) measured by SPECT and renal parenchyma thickness and enhanced CT value measured by CT, and to explore predictive significance of CT in evaluating renal function of patients with hydronephrosis.Materials and Methods One hundred and fifteen patients diagnosed with unilateral hydronephrosis by ultrasound were retrospectively analyzed. GFR% (GFR percentage of affected kidney to the both kidneys) was measured by SPECT. CT% (percentage of affected renal parenchyma thickness to the both kidneys) and enhanced CT% (percentage of enhanced CT value of affected kidney to the both kidneys) were measured by pre- and post-contrast CT scan. According to GFR, the renal function was divided into mild-to-moderate impairment, severely impairment and non-function. Twenty-five volunteers were recruited as control group. CT%, enhanced CT% and GFR%among the four groups were compared, and the correlation of CT% and enhanced CT%with GFR% was analyzed to evaluated CT in predicting renal function.Results CT%, enhanced CT% and GFR% in mild-to-moderate impairment group was significantly greater than those in severely impairment group and non function group (F=20.24, 7.78 and 329.21,P<0.05). GFR% was positive correlated with CT% (r=0.58,P<0.05) and enhanced CT% (r=0.61,P<0.05). Area under curve (AUC) of CT% were 0.54, 0.79 and 0.83 for mild-to-moderate impairment, severely impairment and non-function, with sensitivity of 92.91%, 93.47%, 65.72%, and specificity of 35.33%, 59.47%, and 88.62%, respectively. AUC of enhanced CT% were 0.79, 0.89 and 0.96 for the three groups, with sensitivity of 97.51%, 80.02%, 97.66%, and specificity of 58.14%, 89.82% and 94.27%, respectively.Conclusion There was high correlation between renal function imaging by SPECT and CT in evaluating renal function of hydroneohrosis patients. Pre- and post-contrast CT scan can be used as complements in predicting renal function, and post-contrast CT with high accuracy.