The imaging study on morphological differences of renal tuberculosis and non-tuberculous obstructive hydronephrosis / 中华放射学杂志

ABSTRACT

Objective To investigate the value of morphological features in differentiating between tuberculous hydronephrosis and non-tuberculous obstructive hydronephrosis.Methods The abdominal enhanced-CT examination data of 33 patients with renal tuberculosis and 37 patients with non-tuberculous obstructive hydronephrosis were retrospectively collected.All patients were examined in Peking University First Hospital from September 2009 to November 2016 and confirmed by surgical pathology or clinical manifestation.The longest diameter and largest area of all dilated calices,the anteroposterior longest diameter and the area of renal pelvis at the renal hilum level were measured.The standard deviation of dilated calyx's longest diameter and largest area in each case,the ratio of the mean value of dilated calyx's longest diameter to the anteroposterior longest diameter of renal pelvis and the ratio of the mean value of dilated calyx's largest area to the area of renal pelvis were calculated.These data were compared between the two groups with the t test.Based on the ratio of dilated calyx's longest diameter and largest area to those of renal pelvis,receiver operating characteristic (ROC) curves were used to calculate cut-off values for diagnosis of tuberculous hydronephrosis.Results The standard deviation of dilated calyx's longest diameter and largest area were significantly different in the renal tuberculosis group and the non-tuberculosis group (P＜0.01).The ratio of dilated calyx's longest diameter and largest area to those of renal pelvis of tuberculosis group were significantly larger than those of non-tuberculous group (P＜0.01).ROC analysis of the ratio of dilated calyx's longest diameter to that of renal pelvis showed that the area under the curve was 0.87 (95％ confidence interval 0.77-0.94),the best cut-off point was 0.73,with 81.8％ sensitivity (27/33) and 81.1％ specificity (30/37).ROC analysis of the ratio of dilated calyx's largest area to that of renal pelvis,the area under the curve was 0.90 (95％ confidence interval 0.80-0.95),the best cut-off point was 0.42,with 81.8％ sensitivity (27/33) and 86.5％ specificity (30/37).Conclusions In tuberculous hydronephrosis,the dilatation of calices is more obvious than renal pelvis,and the size of dilated renal calices is remarkably different.In non-tuberculous obstructive hydronephrosis,the dilatation of renal pelvis is more obvious than calices,and the size of dilated renal calices is similar.The morphological differences are helpful in differentiating tuberculous and non-tuberculous hydronephrosis.